Bulletin No. MIE-B6104P

Bulletin No. MIE-B6104P

INSTRUCTION MANUAL
http://www.motoyama-cp.co.jp
本 社 工 場
Main Oﬃce & Factory〒981-3697 宮城県黒川郡大衡村大衡字亀岡5−2 TEL（022）344-4511（代表）/ FAX（022）344-4522
E‒mail:info@motoyama-cp.co.jp
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TEL +81-22-344-4511 / FAX +81-22-344-4522
E-mail: info-overseas@motoyama-cp.co.jp

Models EA91A Flameproof Type of
Explosion-protected Construction●販売・サービスネットワーク

東

京

支

店

〒210-0007 神奈川県川崎市川崎区駅前本町10-5

大

阪

支

店

〒550-0014 大阪市西区北堀江一丁目12-19

クリエ川崎11F

TEL（044）381-8770（代表） FAX（044）381-8772
TEL（06）6535-8111（代表） FAX（06）6535-8655

クリモトビル3F

国

際

営

業

部

〒210-0007 神奈川県川崎市川崎区駅前本町10-5

クリエ川崎11F

TEL（044）381-8771

FAX（044）381-8773

札

幌

営

業

所

〒001-0912 札幌市北区新琴似12条七丁目1-47

リバティタウンP棟101号 TEL（011）766-1520

FAX（011）766-1521

東 北 営 業 所
大衡サービスセンター〒981-3697 宮城県黒川郡大衡村大衡字亀岡５-２

TEL（022）344-1761

FAX（022）344-1762

上 越 営 業 所
上越サービスセンター〒942-0036 新潟県上越市大字東中島2393番地

TEL（025）542-5151

FAX（025）542-5152

関 東 営 業 所
千葉サービスセンター〒290-0046 千葉県市原市岩崎西一丁目５-19

TEL（0436）21-4400

FAX（0436）21-3540

静〒422-8033 静岡市駿河区登呂二丁目10-13

TEL（054）288-2237

FAX（054）288-2239

岡

営

業

所

ハイツ富士１F

名 古 屋 営 業 所
中部サービスセンター〒481-0012 愛知県北名古屋市久地野安田36番地

TEL（0568）26-6681

FAX（0568）26-6631

阪神サービスセンター〒560-0894 大阪府豊中市勝部二丁目18-３

TEL（06）6854-7511

FAX（06）6854-7512

徳 山 営 業 所
周南サービスセンター〒745-0861 山口県周南市新地一丁目６-11

TEL（0834）21-5012

FAX（0834）31-0450

四 国 営 業 所
新居浜サービスセンター 〒792-0851 愛媛県新居浜市観音原町1013-１

TEL（0897）40-0270

FAX（0897）40-0305

大 分 営 業 所
大分サービスセンター

TEL（097）527-3704

FAX（097）522-2352〒870-0108 大分市大字三佐字山ノ神980-1●海外関連会社（大連）有限公司 〒116601

中国

遼寧省大連市金州新区港興大街39-14-7

TEL +86-411-6589-1277

FAX +86-411-6589-1278●海外販売代理店
中国、韓国、台湾、シンガポール、インドネシア、マレーシア、サウジアラビア●SALES AND SERVICE NETWORK

Overseas Marketing & Sales Dept. :11th Floor, Clie Kawasaki, 10-5, Ekimae-honcho, Kawasaki-ku, Kawasaki city, Kanagawa, 210-0007 Japan
TEL: +81-44-381-8771
FAX: +81-44-381-8773
Domestic Sales Branches:Tokyo, Osaka, Sapporo, Tohoku, Joetsu, Kanto, Shizuoka, Nagoya, Hanshin, Tokuyama, Shikoku, Oita

●OVERSEAS AFFILIATED COMPANY

MOTOYAMA VALVE(DALIAN)CO., LTD
Gangxing Street 39-14-7, 8 Jinzhou New District, Dalian-city, 116601 China

ELECTRO-PNEUMATIC
VALVE POSITIONERSTEL: +86-411-6589-1277 FAX: +86-411-6589-1278●OVERSEAS NETWORK

China, Korea, Taiwan, Singapore, Indonesia, Malaysia, Saudi Arabia◆当社は保証期間を原則として製品納入後1年としています。
◆The product will be warranted for one year after delivering this product in principle.
■本取扱説明書の記載内容は、商品の改良等のため予告なく変更することがありますので予めご了承下さい。
■MOTOYAMA is continuously improving and upgrading its product design, speciﬁcations and/or dimensions. Information included herein is subject tochange without notice.
■本取扱説明書は正しい情報の提供を目的としたものであり、本製品の市場性または適合性の保証を証明するものではありません。
■This instruction manual is supplied for information purpose only and should not be considered certiﬁed marketability and conformability of this product.

Printed in Japan
2020.
TKP

Model EA90A Intrinsic Safety Type of
Explosion-protected ConstructionModel EA91A＆EA90A

FOREWORD
Thank you very much for purchasing our Model EA91A/EA90A Electro-pneumatic
Valve Positioner. Take fully notice that the items described below to use this valve
positioner safely and correctly.

1 General Information⑴

This Instruction Manual describes the basic recommended procedures for opera-ting the Model EA91A/EA90A Electro-pneumatic Valve Positioner. Thoroughly readand understand all descriptions in this manual before operation. This Instruction
Manual should always be referred prior to any operations.
⑵

This product is mounted to a control valve as dedicated equipment. Read andfollow all individual procedures in this instruction manual with the instruction manualof control valve when working and operating this product mounted to the control
valve.
⑶

As the result of studying and improving this product without notice, thespeciﬁcations, dimensions, adjustments, illustrations, and other items included inthis manual might be diﬀerent in details. For any questions about the delivered
product or this instruction manual, contact MOTOYAMA sales oﬃce or sales
agency for purchase before operation.

2

Safety Information
To handle this product safely, the symbol marks and signal words shown below
are used in this instruction manual to alert risk as required. The contents of symbol
mark and signal word are described below.
Symbol Mark &Signal Word

Description
This mark with this signal is used when the possibility of

WARNING

death or serious injury to user is assumed if handling thisproduct incorrectly.
This mark with this signal is used when the possibility oflight injury or middle injury to user, or property damage

CAUTIONis assumed if handling this product incorrectly.
This mark and signal are used to comply the instructions

IMPORTANT

to prevent damage of this product or malfunction.

29

Model EA91A＆EA90A

CONTENTS
Page

Page

1. SAFETY INSTRUCTIONS ………………2

5. EXTERNAL CONNECTION ……………15…………2

5.1 Piping and Wiring Systems …………15

1.2 Safety Instructions on Model EA91A Electro-pneumatic Valve Positioner …………2

5.2 Pneumatic Piping ………………………16

1.1 General Safety Instructions

1.3 Safety Instructions on Model EA90A Electro-pneumatic Valve Positioner …………3

5.3 Electrical Wiring ………………………16
6. CALIBRATION ……………………………19

2. GENERAL INFORMATION ………………4

6.1 Advance Check before Calibration …19

2.1 Purpose ……………………………………4

6.2 Adjusting Procedure …………………20

2.2 Applicable Regulation …………………4

6.3 Zero Adjustment ………………………20

2.3 Standard Speciﬁcations ………………4

6.4 Zero Adjustment for Cam ……………20……………5

6.5 Stroke Adjustment ……………………20

2.5 Nameplate Identiﬁcation ………………5

6.6 Split Range Adjustment ………………20

2.6 System Conﬁguration …………………5

6.7 Reverse Positioner Adjustment ……22

2.7 Construction ………………………………6

6.8 Manual Switching Mechanism-A/M Switching …22

3. PRINCIPLE OF OPERATION ……………7

7. MAINTENANCE …………………………23

2.4 Model Numbering System

4. INSTALLATION ……………………………8
4.1 Dimensions ………………………………8
4.2 Installation Conditions …………………94.3 Pre-Installation Check …………………94.4 Installation to Linear Motion Actuator ……10
4.5 Installation to Rotary Motion Actuator…11

4.6 Conformity of Capacity
and Characteristics ……………………12

7.1 Periodic Maintenance …………………23
7.2 Maintenance Procedure………………24
8. TROUBLESHOOTING …………………25
9. REFERENCE INFORMATION …………26
9.1 Predicted Service Life ………………26
9.2 Dimension of Fitting ……………………27

4.7 Installation Dimensions ………………14

1

Model EA91A＆EA90A

1 SAFETY INSTRUCTIONS
1.1 General Safety Instructions
1.1.1 Compliance with Safety Instructions

CAUTION

When handling and operating the electro-pneumatic valve positioner, all the safety instructions herein should
be securely followed.

1.1.2 Conformance with Speciﬁcations

CAUTION

Both the Model EA91A Electro-pneumatic Valve Positioner (ﬂameproof explosion-protected construction) andthe Model EA90A Electro-pneumatic Valve Positioner (intrinsically safe explosion-protected construction)
have been approved in accordance with the Labor Safety and Hygiene Law of "Technical Criteria of Electrical-mechanical Equipment Explosion-protected Construction"(hereafter referred to as "Technical Criteria").
The certiﬁed seal, and the nameplate or the cautionary label describing the speciﬁcations to be required
protecting explosion are attached to each valve positioner in conformance with all speciﬁed requirements.
Check the items described in the certiﬁed seal, and the nameplate or the cautionary label, and use thisproduct.
Model No.

Explosion-protection Type

Applicable
Explosive Gases

EA91A

Flameproof TypeTechnical Criteria, Ex sd ⅡC T6X

ⅡC T6

EA90A

Intrinsic Safety TypeTechnical Criteria, Ex ia ⅡC T５

ⅡC T5

Installation Location
All gases classiﬁed in Group left and Div.1 and 2 Hazard-ous Area. Non-Hazardous Area. (Locations speciﬁed inTechnical Criteria and Division 1 and 2 Hazardous Area)
All gases classiﬁed in Group left and Div.0, 1 and 2 Hazard-ous Area. All Non-Hazardous Area. (Locations speciﬁed inTechnical Criteria and Division 0,1, and 2 Hazardous Area)

CAUTION
1.1.3 Prohibition of Changing Speciﬁcations and Modiﬁcations
Do not change the speciﬁcations or modify the valve positioners by user.

1.2 Safety Instructions on Model EA91A Electro-pneumatic Valve Positioner
1.2.1 Limitation of Installation Locations

WARNINGThe EA91A Valve Positioner can be installed in the hazardous area according to the available explosive gasof the valve positioner.
However, do not install the EA91A Valve Positioner in the Class 0 hazardous area.

1.2.2 Maintenance during Operation

WARNING

Do not perform maintenance of the EA91A valve positioner while the power is being turned ON. Whenperforming maintenance by opening the terminal box with the valve positioner turned ON due tocircumstances, carefully make sure before and during maintenance that the explosive gases are absent using
gas detector.
When impossible to check whether the explosive gases are absent or not, maintenance must be limited tovisual inspection and adjustment of movable parts not requiring the opening of the terminal box such as
zero adjustment and stroke adjustment. Be careful not to generate impact sparks during this maintenance.

1.2.3 Repairs

CAUTIONa ) Turn OFF the power and move the EA91A Valve Positioner to safety place before repairing.
b ) Both mechanical and electric repairs are. limited to restoring the valve positioner to its original condition
in principle.
c ) The use is limited to the repairable degree only using general tools without soldering iron.

1.2.4 Protection against Conventional Short-circuit Current

WARNING

The coil part ﬁlled with resin of the EA91A Valve Positioner is the special explosion-protected construction
compliance with the Technical Criteria. This Technical Criteria requires the "protection against 4000A
conventional short-circuit current for the electrical device or part with resin-ﬁlled construction to beconnected to the external power supply". For the host device such as controller to be connected to the EA91A
Valve Positioner, use fuse or breaker with breaking capacity 4000A or more.
"WARNING" seal is aﬃxed on terminal box.

2

Model EA91A＆EA90A
1.3 Safety Instructions on Model EA90A Electro-pneumatic Valve Positioner
The EA90A Electro-pneumatic Valve Positioner (intrinsically safe explosion-protected construction) consists of
one intrinsic safety device (electro-pneumatic valve positioner) designed and produced following to the new
Technical Criteria and one intrinsic safety related device (safety barrier).
Use the safety barrier individually passed the device test for combining with the EA90A Electro-pneumatic
Valve Positioner. Select the safety barrier that complies with the combination conditions described in Item 2.6.2"Model EA90A Electro-pneumatic Valve Positioner (Intrinsic Safety Type) in this manual.

1.3.1 Limitation of Installation Location

WARNINGThe electrical device with the intrinsically safe explosion-protected construction consists of the combinationof the intrinsic safety device (EA90A Electro-pneumatic Valve Positioner) to be installed in hazardous area
and the safety barrier (intrinsic safety related device) to be installed in non-hazardous area.
The EA90A Valve Positioner can be installed in hazardous area according to the available explosive gas of
the intrinsic safety device. However, do not install the safety barrier to be electrically connected to the
EA90A Valve Positioner in hazardous area unless the safety barrier is used in combination with other explosion-protected construction (ﬂameproof explosion-protected construction, etc.)

1.3.2 Combination with Safety Barrier

WARNING

The safety barrier that does not individually pass the model test in compliance with the Technical Criteria
should not be used by connecting to this electric-pneumatic valve positioner EA90A.
The explosion-protected device type of the safety barrier shall be "ⅡC" and the classiﬁcation shall be "ia".
Be sure to comply with the conditions since there are limitations of inductance and capacitance for safety
rate and external wiring. (Refer to Item 2.6.2 "Model EA90A Electro-pneumatic Valve Positioner (Intrinsic SafetyType)" in this manual for maintenance of the EA90A Electro-pneumatic Valve Positioner.)
CAUTION
1.3.3 MaintenanceConsult with Motoyama for maintenance of the EA90A Electro-pneumatic Valve Positioner in principle.
If performing maintenance by user, read the following instructions herein and carefully follow the instructions
described in Chapter 8 "MAINTENANCE" for speciﬁc procedures.
WARNING(1) Maintenance of EA90A Valve Positioner
When performing maintenance the EA90A Valve Positioner installed in hazardous area, carefully make sure
before and during maintenance whether the explosive gases are absent or not by using gas detector.

(2) Maintenance during Operation
Do not perform maintenance of the EA90A Valve Positioner while the power is being turned ON.
When performing maintenance with the valve positioner turned ON due to circumstances, maintenance mustbe limited to visual inspection and adjustment of movable parts such as zero adjustment and stroke
adjustment.
CAUTION(3) Repairsa ) Turn OFF the power, disconnect the external wiring, and then move the EA90A Valve Positioner to non-hazardous area.
b ) Both mechanical and electric repairs are restricted to only restoring the valve positioner to its
original condition in principle.
c ) The repair by user shall be limited to repair using general tools without soldering iron.

(4) Veriﬁcation of Intrinsic Safety
CAUTION
Check the following items in non-hazardous area when conﬁrming intrinsic safety of the EA90A Valve
Positioner at periodic maintenance of the EA90A Valve Positioner and at replacement of the parts forrepairs.
Check the insulation performance by applying voltage with 500V for one minute to the plus (+)
terminal or the minus (‒) terminal, and the grounding terminal of the terminal block.

3Model EA91A＆EA90A

2 GENERAL INFORMATION
2.1 Purpose
The Model EA91A and EA90A Electro-pneumatic Valve Positioners are mounted to control valves. They convert
electric signals from the controller into pneumatic pressure to control the opening of the control valve properly.
The valve positioners are of explosion-protected construction, and are improved the positioning accuracy
and response performance of process control valves installed in hazardous areas.

2.2 Applicable Regulation
The valve positioners delivered are passed the test in accordance with technical criteria of explosionprotected construction standard for electrical machine and equipment (issued by the Ministry of Labor inJapan, No. 556, 1996).

2.3 Standard Speciﬁcations

Type

Model EA91A

Model EA91AC

Model EA90A

Model 90AC

Lever Type(Single Action)

Cam Type(Single Action)

Lever Type(Single Action)

Cam Type(Single Action)

Input Current

4 to 20mADC

Input Resistance250Ω

Supply Air Pressure

Max.

500kPaG(5.0kgf/cm2G)

Structure

Intrinsic safety type
(TIIS) Ex ia ⅡC T5(NEPSl) Ex ia ⅡC T5 Ga

Explosion-protection

Protection ClassIEC IP65（※IEC IP66）

Connection

Flame-proof type
(TIIS) Ex sd ⅡC T6X(NEPSl) Ex d mb ⅡC CT6 Gb(KOSHA) Ex d mb ⅡC T6

Air Piping Connection

Rc 1/4（PT 1/4）

Conduit Connection

G 1/2

Output Characteristics

LinearCharacteristics

Standard Stroke

10 to 65mm
60°
Eq%
60°
（Linear）※(※over 65 to 130mm)
90°
Linear

10 to 65mm
60°
Eq%
60°
（Linear）※(※over 65 to 130mm)
90°
LinearLinearity≦±1.0%F.S≦±2.0%F.S≦±1.0%F.S≦±2.0%F.S

Hysteresis Error≦

1.0%F.S≦

1.5%F.S≦

1.0%F.S≦

1.5%F.S

Dead band≦

0.1%F.S≦

0.3%F.S≦

0.1%F.S≦

0.3%F.S(substance alone)

Repeatability≦±0.3％ F.S

Air Consumption≦6.0ℓ/ min Nor (Sup. 140kPaG (1.4kgf/cm2 G), Signal 50％)

Maximum

Supply and Exhaust of air

7.0 ℓ/min Nor (Sup. 140kPaG (1.4kgf/cm2 G), Signal 50％)

Insulation Resistance≧100MΩ (with 500V DC Mega between terminal and case)

Ambient Temperature
Painting
Mass−40℃ to 100℃（−20℃ to 60℃ for explosion protection）
Munsell 2.5PB 5/8 (Blue)
Approx. 2.9kg【Notes】 (1) ※Available as options on customer's request.
(2) Model EA90A/EA90AC positioner is not available for reverse action type pilot.

4−20℃ to 60℃

Model EA91A＆EA90A
2.4 Model Numbering System
Structure

Specifications

Basic Model No.

Flameproof TypeEA91A

Intrinsic safety Type

EA90A

Specification CodeDisplacementtransfer Method

Lever Type（Blank）

Cam Type

Ｃ

Method of Leading
External Cable

Conduit Type (standard)（Blank）
Ｔ

Explosion-proof conector with packing Type(option)【Note】 If method of leading external cable is explosion-proof connector(Spec. code:T), applicable standard is JIS, ﬂame-proof.
In case of NEPSI ﬂame-proof type, ﬂame-proof packing connector(cable glands), certiﬁed by NEPSI, shall be supplied bycustomer.

2.5 Nameplate Identiﬁcation(1) The safety certiﬁed seal nameplate (Oﬃcial Certiﬁcation Plate) is attached on the top of positioner case.

労（●●●.●）検 ※1
※2
株式
会社

本山製作所

［Notes］※１．Described date may be diﬀered bytime of manufacture.
※２．To be described authorization Nos. in.

(2) The explosion protection "WARNING" nameplate is attached on the upper part of terminal box.
(EA91A and EA90A have diﬀerent contents each other.)(3) The speciﬁcation nameplate is attached on the right side of positioner case.
(4) The oriﬁce plate classiﬁcation nameplate is attached on the pilot cover.

2.6 System Conﬁguration
2.6.1 Model EA91A Electro-Pneumatic Positioner (Flameproof Type)
Hazardous Area
Model EA91A
Electro-pneumatic Positioner

Non-hazardous Area
General Equipment

Power Source
4〜20mA DC

5

Model EA91A＆EA90A
2.6.2 Model EA90A Electro-Pneumatic Positioner (Intrinsic Safety Type)
Hazardous area

Non hazardous area

Mdel EA90A
Electro-pneumatic positioner

Safety barrier

General device
Source

4〜20mA DC

Earth bus bar
Safety earth

To combine with a safety barrier
The safety barrier which is used in combination with electro-pneumatic positioner EA90A must be
TIIS certiﬁed type.
For the safety barrier selection, please refer to the following data for Intrinsically safe approval ofmodel EA90A.

Caution※2① Performance classiﬁcation and Groupia IIC② Permissible maximum values
Ui = 30V, Ii = 100mA , Pi = 0.75W③ Parameters
Ci = negligibly small
Li = negligibly small※2

TIIS ; Technology Institution of Industrial Safety (JAPAN)※ Motoyama distribute recommended safety barriers. If you are interested or have any questions about the product,
please contact our sales oﬃces or sales agents.

IMPORTANTDo not connect a constant voltage power supply to the Electro-pneumatic positioner EA90A, which
has an intrinsic safety type. Overcurrent may ﬂow and damage the diode inside the positioner.

2.7 Construction
2.7.1 Lever Type
Restriction

2.7.2 Built-in Cam Type

Right-hand lateral faceSupply Air Connection

Output Air Connection
Supply Pressure Gauge

Output Pressure Gauge
Auto/Manual Switching Screw

Cam
StrokeAdjustment Knob

Zero Adjustment Knob
Terminal Box

Conduit Connection

NozzleFlapper
Body

6

Pilot
Valve

Model EA91A＆EA90A

3 PRINCIPLE 0F OPERATIONThe Model EA91A and EA90A Electro-Pneumatic Positioner is used as accessory measuring instrument topneumatic control valves. This converts electric signals from the controller into pneumatic pressure to position
the opening of pneumatic control valve.
As the signal current from the controller or manual operator increases, the torque motor coil generates magnetic
pole on the armature. The armature receives rotary torque in the counter-clockwise direction, and varies the
distance between the nozzle and the ﬂapper. As a result, the nozzle back pressure changes, and the pilot
valve reacts accordingly.
The output air of pilot valve is supplied to the diaphragm motor, and moves the control valve. The valve stem
movement is mechanically transmitted to the feedback spring through feedback lever, transmission lever, andstroke adjustment lever, and balances the valve movement at a position that is equal to the generated torque dueto the signal current.

Figure of Principle of Operation

NozzleBack Pressure

Pilot Valve
Inner Valve

ExhaustFilterRestriction

Auto/Manual
Switching Screw
NozzleOutputOriﬁce Plate

Feedback Spring
Transmission Pin
Stroke Adjustment Lever
Stroke Adjustment Knob
Actuator

Flapper
Supply Press.
Zero Adjustment Knob
Zero Adjustment Spring

Valve Stem

Feedback Lever

Conduit Connection
Balancer

Torque Motor
Armature

Transmission Lever

Torque Motor Coil7

Model EA91A＆EA90A

4 INSTALLATION
4.1 Dimensions Unit : mmLever Type
129

Actuator Size(Outer Dia.)Ａ

φ200 to φ330

Ｂ

φ400 to φ650

51

7

164.5

（Left Lateral View）

Air Connection
2-Rc 1/4

Type

45.5
58.5

Conduit Connection

137
218

146 (A Type)206 (B Type)

G 1/2

Built-in Cam Type

51

7

（See above as left lateral view）

45.5

137
3

218

Leading External Cable◇Conduit Type

Model : EA91A(C), EA90A(C)◇Flameproof Packing Type

(Additional Option):Applicable cable OD:φ9.1 to φ11
Model : EA91A(C)TKXB-LO-16F(Special Option)

153.5
31

12.5

135

51

KXB-LO-16(Standard)8Model EA91A＆EA90A
4.2 Installation Conditions
4.2.1 Locations for Installation
The models EA91A and EA90A electro-pneumatic
positioner can be installed and used at the hazardous
area in accordance with gases to be used.
4.2.2 Environmental Conditions
The applicable environmental conditions are shown in
the right table.

CAUTION

Model
Environmental
Conditions

Model EA91A
Model EA90A
Flameproof Type Intrinsic Safety Type

Ambient Temp. −20℃ to +60℃ −20℃ to +60℃
AtmosphericPressure

80 to 110 kPa, Absolute Press.

※The ambient temperature in the non-explosionprotected environment is ‒40℃ to +100℃①If the equipment may cause to be exposed to the radiation from plant facilities and theambient temperature may be abnormally high, take appropriate measures to insulate theheat.
② If installing the equipment under the special conditions (vibration, corrosive atmosphere,
always be exposed to drain), take appropriate measures to protect from such conditons.

※If the device is in conditions of ① or ②, contact our sales branch or sales agent.

4.3 Pre-Installation Check

Bracket (Refer to Item 9.2)

(1) Nameplate Check (related to speciﬁcations and For Model 3800
explosion-protected type)
Check the content of the nameplate attached to the main
body of the positioner whether the ordered speciﬁcationis conformed with.
(2) Appearance Check
Check the presence of damage on the device due totransport.
(3) Accessory Identiﬁcation
Lever Type : Bracket, Stem Clamp (Connector Arm
included), Feedback Lever, and Connector For Model 2900
Pin
Buit-in Cam Type : Bracket, Connecting Shaft, Set
Screw, Spacer Bolt, and Set Spring

For Model 2800

For Model 3300

Also, the relative bolts, nuts, vises, and washers, etc. areattached.
(4) Pressure Gauge Check

IMPORTANT

Be sure not to provide overpressure because
the pressure gauge appropriate for supply
air pressure is installed.

Stem Clamp

Connector Arm(5) Oriﬁce Plate Check
Remove pilot cover, and check oriﬁce plate appropriate
for actuator capacity is installed and set.

IMPORTANT

Although oriﬁce plate that conforms to theorder speciﬁcations is installed at factory
shipment, check it again. (Refer to Item 4.6.1)※Refer to Item 9.2 "Dimension of Mounting Hardware" fordimension of each part.

Feedback Lever

9Model EA91A＆EA90A
Installation Drawing ofActuator for Model 3800

4.4 Installation to Linear Motion Actuator
Use bracket suitable for actuator, and install the

Actuator

Positioner properly. When installing, use mounting
threaded hole on the back of the Positioner and mounting threaded hole in the front of the actuator.
⑴

Connecter arm should be attached to stem clamp
and these assembled parts should beclamped to

Diaphragm Stem

diaphragm stem.

IMPORTANTAt this point, attach the stem clamp upward
approx. 5 to 10 mm from lock nut. Fix theconnector arm so as to be parallel to the front
surface of actuator.

⑵

Attach the bracket to actuator.

⑶

Install the Positioner to bracket.

⑷

Install air piping. (Refer to Item 5.2)⑸

Change A/M Switch to M(Manual) and turn handle

5 to 10mm

Fixing Bolt
Bracketof air ﬁlter regulator to supply air pressure to actuator
for letting the valve stroke come up to 50％ position.
⑹

To be squareFix the connector pin to feedback lever andconnector arm.

IMPORTANT① Fix the connector pin so that feedback thelever and connector arm are positioned inhorizontal and parallel (square to positioner)at midpoint (50％) of the stroke.
② Assemble the connector pin between
feed-back lever and set spring.
③ Check that the stroke adjustment lever in the
Positioner is square.

Stem Clamp
Installation ofFeedback Lever for Front Side
Reverse Action(RA)Connector Arm※Model 3800, Model 2800, and other linear motion actuator
may be applied the same procedures as mentioned above.

Position of Stroke Adjustment Lever

Set Spring
Feedback Lever

Direct Action（DA）

Reverse Action（RA）

Connector Pin

Installation ofFeedback Lever for Back Side
Direct Action(DA)

Set Spring

Feedback Lever
Connector Pin

10

Model EA91A＆EA90A
4.5 Installation to Rotary Motion Actuator⑴ Attach the spacer bolt.
Tighten the spacer bolt to crank box. (Screw short side of spacer bolt threaded part.)⑵ Mount the connecting shaft.
Insert the lock nut, spring washer, and indicator to connecting shaft, and screw the connecting shaft to M8screw of valve shaft.
⑶ Fix the indicator.
Check that valve action is air failure-open or air-failure close. Then, ﬁx the indicator to appropriate position,
open or close, on indicator scale with lock nut.
※The hole position of set spring must be vertical to connecting shaft.

IMPORTANT

Set the inserting hole on connecting shaft vertically and the set screw on connecting rod
horizontally to proper position.

⑷ Attach the bracket.
Attach the bracket to the preinstalled spacer bolt.
⑸ Attach the connecting pipe.
Attach the connecting pipe to the serrated portion of the feedback shaft at back side of the positioner withset screw.
※The position of the set screw must be horizontal.

⑹ Mount the positioner.
Insert the connecting shaft to the connecting pipe and mount the positioner to spacer bolt.

IMPORTANT

Check the positioner and connecting shaft the connecting pipe and the feedback shaft are
ﬁxed in alignment, when the bracket is tighten.

⑺ Attach set spring.
Attach the set spring to the connecting pipe and connecting shaft.
IMPORTANTThe set spring is the important part to absorb play between connecting shaft and set screw.
Be sure to attach the set spring so that the function is served fully.

⑻ Install air piping. (Refer to Item 5.2)
Positioner Installation Drawing
to Actuator Model 2900

Diaphragm Actuator

Elector-pneumatic
Positioner
Crank Box

Bracket
Shaft

Spacer Bolt

Set Screw Connecting Pipe

Indicator
Shaft

Feedback Shaft

Connecting
Shaft

Connectingpipe

Set Screw（Horizontal）

Spring Washer
Lock Nut

Hole Position（Vertical）
Connecting Shaft

Set Spring11Model EA91A＆EA90A
4.6 Conformity of Capacity and Characteristics
4.6.1 Selection of Oriﬁce Plate for Actuator Capacity
For the purpose of obtaining stable actuation of positioner with small-capacity actuator to large-capacity
actuator, the Models EA91A and EA90A Electro-pneumatic Positioner are equipped with appropriate oriﬁce
plate in accordance with actuator size.
⑴

The oriﬁce plate has two types in accordance with the actuator size. One standard plate can becompatible with three kinds of size of actuator.

⑵ When using each size of oriﬁce plate, align V groove position of oriﬁce plate with cut position of gasket.
⑶ When replacing or changing the position of oriﬁce plate, remove pilot cover, and loosen three screws
ﬁxing pilot assembly.
⑷

General classiﬁcation for usage of oriﬁce plate, see table below.

⑸

To install booster relay for actuator size ∅270 and larger, use V groove 1 of oriﬁce plate No.1.

⑹ Model 3800 actuator ∅280 and larger with rated travel 15, 20, 25mm and spring range 20 to
100kPaG(0.2 to 1.0kgf/cm2), use V groove 3 of oriﬁce plate No. 1.
Oriﬁce Plate
for Standard Size

Oriﬁce Plate for
Small Size Actuator

V Groove 1

V Groove with Black-coatingNo

1

Positioner
Types
Linear,Buit-in Cam
Linear,Buit-in Cam
Linear,Buit-in Cam

2V
Groove3

V
Groove2

LinearActuator Size

No. of Groove
for Identiﬁcation∅270 to ∅330

V Groove 1∅400 to ∅650

V Groove 2∅240

V Groove 3∅200

V Groove withBlack-coating

Pilot Cover

Pilot Ass'y

Gasket(B)Cut for Identiﬁcation
Oriﬁce Plate

Pilot Ass'y

Gasket(A)Manifold
V Grooves

Pilot CoverFixing Screw
for Cover

V Grooves

Gasket(B)12Gasket(A)Oriﬁce PlateModel EA91A＆EA90A
4.6.2 Selection of Buit-in Cam⑴ The cam for linear motion has three types. The three typesof cam are described in the table below.
Rotating Angle

Action① Linear

60°
, 90°

DA, RA② Eq％

60°

DA, RA70°

DA, RA

Characteristics③ Eq％ (Available only for
Model 2993)

Flange Nut

Cam⑵ The starting point for characteristics and identiﬁcation of
DA (start air supply) and RA (stop air supply) are stamped on
the cam.
⑶

Loosen ﬂange nut to select cam or to adjust position of

cam.
Eq％ CamLinear Cam

ER
A

70°Eq％ Cam

RA

7ER

7ED

EDA
Starting Pointof CamStarting Pointof CamStarting Pointof CamBack Side of DA

4.6.3 Selection of Pilot CoverThe exhaust hole of pilot cover changes due to installation position of the positioner. Refer to the ﬁgure
below, and check the top and bottom of pilot cover.
※The pilot cover is machined to meet designated position if the installation position is speciﬁed. However, if changing
the installation position in ﬁeld, handle with extra attention.

Top

Top

BottomExhaust Hole

BottomExhaust Hole

Install pilot cover after preparing
the through hole.
(The hole can be opened by lightly
pushing from the inside with driver.)13

Model EA91A＆EA90A
4.7 Installation Dimensions
4.7.1 Model 3800 Actuator
Unit : mm

L

Actuator
Size

A

B

C

D

L

N24

290

77

45

185

215

N28

290

77

45

185

225

N33S

290

77

45

185

233

N40

325

100

58

195

312

C
A

B

D

4.7.2 Model 2800 Actuator

Unit : mm

Actuator
Size

A

B

C

D

L

240, 280 241

125

93

193

250

330
L

241

125

93

205

270

400, 500 241

185

143

223

305

185

143

296

405

650S

241

C
A

B

D

4.7.3 Model 2900 Actuator

Unit : mm

Actuator
Size

A

14

195

Dimension A＃2916B（V）＃2911-1M

＃2992
（−A）

240H
（P）

230

250

280H

240

250

330H
（P）

240

250

400H
（P）

270

265

500H
（P）

270

295

Model EA91A＆EA90A

5 EXTERNAL CONNECTION
5.1 Piping and Wiring Systems
5.1.1 Model EA91A Electro-pneumatic Valve Positioner (Flameproof Explosion-protected Construction)
Air Filter Regulator

Control Valve

Supply Pressure
Model EA91A Electro-pneumatic Valve Positioner

Electro-controller

Hazardous Area

Non-hazardous
Area

5.1.2 Model EA90A Electro-pneumatic Valve Positioner (Intrinsic Safety Construction)

Air Filtere Regulator

Supply Pressure

Control Valve

Electro-controller

Model EA90A Electro-pneumatic Valve Positioner

Non-hazardous
Area

Hazardous Area

Safety Barrier

15Model EA91A＆EA90A
5.2 Pneumatic Piping

IMPORTANTDA(Direct Action)①Before piping, fully purge the air tube, andcompletely remove water, oil, rust, and otherforeign matters.
②Always use dry clean air for supply air.

5.2.1 Piping⑴ The electro-pneumatic valve positioner has twoconnectors for supply air (SUP) and output air(OUT). The Rc1/4 screwed type is used forconnector.
⑵ For supply air (SUP), perform piping from theair ﬁlter regulator.
⑶ For output air (OUT), perform piping to the actuator.
⑷ Use ∅6/4 or ∅8/6 of general type copper tube
(MOTOYAMA adopts PVC coated copper tube as
standard.)⑸ After completing conduit piping, check for leakage
from piping.

OUT

SUP

RA(Reverse Action)

OUT

SUP

WARNING

5.3 Electrical Wiring※If there is a possibility of the inﬂuence on thepositioner due to noise, use shielded cable foravoiding the noise.
5.3.1 Model EA91A Electro-pneumatic Valve
Positioner (Flameproof Explosion-protected
Construction)⑴ Connect wires in accordance with the wiring
diagram in Item 5.1.1.
⑵ The parallel pipe female thread G1/2 female
screw is used for conduit connection.
⑶ Perform wiring in accordance with leading
procedure for external conduit referring to "New
Recommended Practice for Explosion-protectedElectrical Installations".
5.3.1.1 Leading Procedure for Flameproof Thread
Connecting Type of Conduit Tube
⑴ Perform thread connection securely using steel
plate conduit tube (JIS C8305) and lock nut (JISC8330) for steel plate conduit tube.
⑵ Place sealing ﬁtting near leading port of conduit
tube, and make the leading opening airtight withcompound.
⑶ For connection of EA91A Electro-pneumatic Valve
Positioner with terminal box, accessories for wiring,
conduit tube of sealing ﬁtting, etc., ﬁx with lock nut
with more than 6 threads of eﬀective threadconnected. Also, make the port watertight at thesame time.

16

Example of Leading
External Conduit

Shrouding Screw

Terminal Box

Explosion-protected Nipple

Compound Charging Box(Flameproof Type
Sealing Fitting)

Conduit Tube

Insulated Wire

Model EA91A＆EA90A
5.3.1.2 Leading Procedure for Flameproof
Packing Type (Optional Speciﬁcations)
For connector of ﬂameproof packing type, use
the following two connectors certiﬁed at thesame time of EA91A and EA91AC.

5.3.1.3 Connecting Procedure⑴

Loosen the shrouding screw (M3 Hexagon

Socket Set Screw), and remove terminal cover.
⑵

Connect cable to terminal block.

Terminal Screw Size : M4

① KXB-LO-16 (Standard)Standard Wiring (Positioner Wiring)② KXB-LO-16F

Right Terminal (−) (Black Colored Lead Wire)(Speciﬁed, Special Speciﬁcations)

Left Terminal (+) (Red Colored Lead Wire)※Impossible to use connector other than two

Reverse Positioner (Model EA90A is not applicable)

connectors described above.
KXB-LO-16

Right Terminal (Red Colored Lead Wire)

KXB-LO-16F(Standard)(Special Specifications)

Left Terminal (Black Colored Lead Wire)
Even if connecting reverse positioner, perform
wiring in accordance with the indication ofterminal. (Wiring has been converted and adjusted to reverse positioner by MOTOYAMA.)⑶

After completing connection, screw-in the
shrouding screw to terminal cover, and lockTerminal Cover
Shrouding Screw

31

WARNING

12.5

135

153.5

the shrouding screw.

Special O-Ring
Lock Nut
Connecting Body

※The cable to be connected shall be equal

Rubber Packing

to or better than vinyl insulated vinyl sheath
cable for control "CVV" (JIS C3401).
⑴ Process end of cable using crimp-styleterminal. Refer to the table shown below

WasherO-RingHexagon Socket Head Set Screw
Clamp
Pan head machine screw with cross hole
Cable Glandfor outside diameter of cable.

Union Cover⑵ Screw-in connecting assembly to terminal box, and ﬁx with lock nut.
⑶

O-RingUnion Coupling with Set Screw

Insert cable gland, union coupling, andunion cover to the cable.

⑷ Then, insert washer and rubber packing toLeft Side(＋)

Right Side(−)

the cable, screw-in cable gland securely, andlock the hexagon socket head set screw totighten clamp.
⑸ Two types of the rubber packing for cable
are included.

⑹

∅D

∅20

Basic Shape of
Rubber Packing

Unit : mm
Nominal Sizeof Packing

GroundInside Diameter Outer Diameterof Packingof Cable
∅d

10

∅10

∅9.1 to ∅10

11

∅11

∅10.1 to ∅11

Tighten union coupling and union cover.

Ground17Model EA91A＆EA90A
5.3.2 Model EA90A Electro-pneumatic Valve Positioner (Intrinsically Safe Explosion-protected Construction)

CAUTION
The Model EA90A Electro-pneumatic Valve Positioner is designed to ensure intrinsically safe. However,electric or magnetic energy from other electric apparatuses and wires may cause adverse aﬀections on
the intrinsic safety system. To avoid these aﬀections, perform external wiring in accordance with the
instructions described below. For details, refer to"New Recommended Practice for Explosion-protectedElectrical Installations".
⑴ Identify intrinsically safe circuits and un-instrinsically safe circuits, and separate intrinsically safe
circuits from other electric circuits.
⑵ Take appropriate measures to prevent inﬂuences such as electrostatic induction and electromagnetic
induction.
⑶ Minimize inductance and capacitance of the wires as much as possible, and always make them lower
than maximum value if operating condition is speciﬁed.
⑷ Protect the wires against external damages.
⑸ Be sure to ground uncharged open metallic parts.

■Wiring Procedure⑴

Connect wires in accordance with the wiring diagram shown in Item 5.1.2.

⑵

The parallel pipe female thread G1/2 female screw is used for conduit connection.

⑶

Condition for External Wiring of Intrinsically Safe Circuit :Set the parameter of intrinsically safe circuit and the parameter of safety barrier so that the conditions
described below are satisﬁed.
Lw ≦ LoCw ≦ Co
Lw : Inductance of External Wiring of Intrinsically Safe Circuit
Lo : Permissible Inductance of Intrinsically Safe Circuit
Cw : Capacitance of External Wiring of Intrinsically Safe Circuit
Co : Permissible Capacitance of Intrinsically Safe Circuit
Eﬀective internal inductance and eﬀective internal capacitance of EA90A Electro-pneumatic Valve
Positioner are negligibly small.
⑷ Use insulated wires or cables for Intrinsically Safe Explosion-protected Construction. Use metal tubes,
metal conduits, or metal protective tubes as needed to mechanically protect external wiring and prevent
induction.
⑸

Place the Model EA90A Electro-pneumatic Valve Positioner away from other electric apparatus asfar as possible, and separate its wiring from the others.

18Model EA91A＆EA90A

6 CALIBRATIONIMPORTANT

Each unit of the Positioner is completely
calibrated and inspected before delivery.
However, slight error may occur due to vibration and impact during transportation.
Be sure to perform calibration and loop
test of the Positioner before operation.

WARNING

OUT
SUP

Zero Adjustment
Knob

Do not open the cover of the terminal box forusing Flameproof Explosion-protected type
(Model EA91A) during power-on. Whencircumstances require opening the cover during
power-on, properly make sure that no explosive
gases are present using gas detector before
maintenance.In this connection, it is possible toinspect and adjust with the cover removed.
However, be very careful not to generate impact
sparks during maintenance.

6.1 Advance Check before Calibration⑴ Switching of Direct/Reverse Action for Linear
Motion Actuator

Supporting Point(Decrease output:
turn upward,
Increase output:
turn downward)

Lock Screw

Stroke Adjustment Lever
Stroke Adjustment Knob

Installing Position of Stroke
Adjustment Lever for Direct Action

Perform switching of direct/reverse action of
the Positioner by changing the supporting
point (minus groove of lever column) of stroke
adjustment lever.
Supporting Point of DA (Direct Action) :Upper Side
Supporting Point of RA (Reverse Action) :Lower Side⑵ Switching of Direct/Reverse Action for Cam
It is possible to switch action by mounting the
cam in accordance with inscription on cam.
(Inscription : DA, RA)⑶ Check of Stroke Adjustment Lever

Installing Position of Stroke
Adjustment Lever for Reverse Action

Make sure that the stroke adjustment lever isplaced vertically at the 50% point in rated
stroke (or angle). Perform manual switchingmechanism with "M" for manual operation.
(Refer to Item 6.8 "Manual Switching Mechanism")

IMPORTANT

When the stroke adjustment lever leans
with same angle in both right and left
angle with reference to the leaning angle
50％ as origin, the speciﬁcations oflinearity will be satisﬁed.

19Model EA91A＆EA90A
6.2 Adjusting Procedure⑴ Set input signal to 50％. Then, adjust to 50％
point of speciﬁed stroke with zero adjustment
knob.
⑵ Move the input signal between 25％ and 75％,
and make sure that the stroke is set to 25％
and 75％ of speciﬁed stroke. If the stroke is
not within tolerance, adjust input signal tospeciﬁed stroke by repeating stroke
adjust-ment and zero adjustment while checking plus or minus of the speciﬁed stroke. If
speciﬁedstroke point is obtained with the adjustments,
the input signal between 0％ and 100％ willapproximately adjust reference stroke point.
⑶ If shut-oﬀ power of valve is considered asimportant, check as follows. For DA (Direct
Action), make sure that the input signal is greater than the reference value and the nee-dle ofpressure gauge in OUT side indicates approx.
supply pressure. For RA (Reverse Action),make sure that the input signal is less than
the reference value and needle of pressuregauge in OUT side indicates approx.
zero.
※For cam type, basically perform same proce-dures since the speciﬁed stroke is the speci-ﬁed
angle. However, perform cam position adjustment described in Items 6.1 and 6.4.

6.3 Zero Adjustment (Common toLinear Type and Built-in Cam
Type)

6.5 Stroke Adjustment(Common to Linear Type andBuilt-in Cam Type)⑴ Loosen lock screw ﬁxing stroke adjustment
knob of the stroke adjustment lever.
⑵ If making the stroke (angle) wider, adjustby turning screw of stroke adjustment leverclockwise.
⑶ If making the stroke (angle) narrower, adjustby turning screw of stroke adjustment levercounterclockwise.
⑷ Performing these adjustments while watching the indication −＋ on the stroke
adjustment lever.
⑸ After setting is completed, be sure to tighten
the lock screw securely.

Lock Screw
Cam

Flange Nut
StrokeAdjustment Needle

Stroke Adjustment Knob

⑴ The output increases (start point rises) byturning the zero adjustment knob clockwise(downward).
⑵ The output decreases by turning the zeroadjustment knob counterclockwise (upward).

6.4 Zero Adjustment for Cam
The zero origin position of proper part of cam isinscribed on cam surface. Check the opening ofvalve, loosen ﬂange nut and adjust the position.

20

6.6 Split Range Adjustment(Common to Linear Type andBuilt-in Cam Type)⑴ The split range has four types such as 1/1.5,
1/2, 1/3, and 1/4 for both linear and built-in cam
types.
⑵ For replacement parts of split range, use
feedback spring and zero adjustment spring.
The identiﬁcation table is shown below.
⑶ Move the stroke adjustment knob of stroke
adjustment lever to meet required stroke.
Then, adjust the stroke in accordance withprocedures from Items 6.2 to 6.5 while inputt-ing the input signal as speciﬁed in the speciﬁcation.

Model EA91A＆EA90A(4) Lever Type: Actuator Type #3800(7) Built-in Cam Type: Linear Cam(Size: N24 to N40), Stroke: 5 to 65mm

(0°to 60°or 0°to 90°)

Zero
Adjustment

Identification Color

None Blue None Blue Black White Red Yellow

Feedback Spring

Standard

●

●

1/1.5

●

●

1/2
1/3
1/4

●
●

●
Note.1☆

Note.8☆

Note.2☆
●●

Kinds of Spring

Zero
Adjustment

Identification Color

None Blue None Blue Black White Red Yellow

Note.1☆

Standard

●

1/1.5

●

Split Range

Split Range

Kinds of Spring

Note.3☆

Note.4☆

Note.4

●

☆

1/2

●

1/3

●

1/4

●

Feedback Spring●

Note.1☆

●●

Note.2☆
●●

Note 1. 0°to 90°Cam Standard
Note 2. 0°to 90°Cam Split Range 1/2(5) Lever Type: Actuator Type #2800(Size: 500 to 600), Stroke: 5 to 130mm
Zero
Adjustment

Identification Color

None Blue None Blue Black White Red Yellow(8) Built-in Cam Type: Eq% Cam(0°to 60°)

Feedback Spring

1/1.5

●

●

1/2

●

●

1/3

●

1/4

●

Note.1☆

☆

Note.6☆
●☆

☆

Standard●

Note.7

1/1.5

●

1/2

●

1/3

●

1/4

●

☆
☆

Note.4☆

Note 1. #3800 N24 to N33S: Stroke 5 to under 15mm
N40: Stroke 15mm
#2800 φ500 to 650: Stroke 15mm
Note 2. #3800 N24 to N33S: Stroke 20mm or more
N40: Stroke 38 to under 65mm
Note 3. #3800 N40: Stroke 65mm
Note 4. #3800 N24 to N33S: Stroke 38mm
Note 5. #2800 φ650: Stroke 105mm or more
Note 6. #2800 φ500: Stroke 38mm or more
φ650: Stroke 38 to under 105mm
Note 7. #2800 φ500 to φ650: Stroke 70mm or more
Note 8. #3800 N40 #2800 φ500 to φ650: Stroke 65mm

(6) Lever Type: Actuator Type #3300,
Stroke: 12.7mm

Identification Color

None Blue None Blue Black White Red Yellow

Split Range

Kinds of Spring

Zero
Adjustment

Feedback Spring

●

●

1/1.5

●

●

1/2

●

●

1/3

●

●

1/4

●

None Blue None Blue Black White Red Yellow

Note.5●

Standard

Identification Color

Feedback Spring

●
●
●
●
●

(9) Built-in Cam Type: Actuator Type #3900(Standard Cam for Linear, Special Cam for Eq%)
Kinds of Spring

Zero
Adjustment

Identification Color

None Blue None Blue Black White Red Yellow

Linear●Zero
Adjustment

Eq%●

Kinds of Spring

Note.1

Split Range

Standard

Note.8Note.5

Split Range

Split Range

Kinds of Spring

Standard

●

1/2

●

Standard

●

1/2

●

Feedback Spring

●
●

●
●

●

21

Model EA91A＆EA90A（10） Calculating Method for Lever Type Positioner(Example)
Rated
StrokeSplit Range Required Stroke

Calculation

15 mm

1/2

30 mm

15 × 2 = 30mm

38 mm

1/2

72 mm

38 × 2 = 72mm

38 mm

1/3

114 mm38 × 3 = 114mm

6.8 Manual Switching Mechanism-A/M Switching (Common to Lin-ear Type and Built-in Cam Type)
Before operating manual switching mechanism,make sure that the ﬁltered regulator is placed at
the line of supply side of the positioner.(Due tosupply bypass method)※Therefore, when the stroke is greater than 65mm, thefeedback spring (or zero adjustment spring) will be
special speciﬁcation.
※For details except items described above, contact oursales oﬃce or sales agent in your region.
IMPORTANT

6.7 Reverse Positioner Adjustment(Common to Linear Type andBuilt-in Cam Type)

Manual Changeover
Switching Mechanism

6.7.1 In case of Reverse Positioner Speciﬁcations(Adjusted at Our Factory)⑴ Connect wiring in accordance withindi-cations (+) and (−) of terminal. (Reverse
positioner wiring has already been performed
and adjusted at our factory)⑵ Make sure that action of reverse positioner
is properly performed by increasing/decreasing
the input signal.
⑶ Perform operating adjustment in accordance with the procedures from Items 6.2
to 6.5, and check with loop test.

IMPORTANT①If not venting through the ﬁlteredregulator, it might apply excessive
pneumatic pressure to the positioner
or the actuator.
②If not inputting through the ﬁlteredregulator, it might be in danger thatthe air pipe of the positioner isclogged up with foreign matter.

SUP

OUT

If adjusted at our factory, nameplate of"Reverse Positioner" is stuck at the backof the terminal cover.

Stopper Screw
A/M Switching Screw

6.7.2 In case of Changing to Reverse Positioner
Speciﬁcations at Site.
⑴ Zero adjustment spring must be replaced with blue
colored spring. For your inquiry of the spring, pleasecontact us or our sales agent in your area.
⑵ Connect wiring with (+)and (−) terminals in reverseof.(Reverse positioner wiring is performed and adjusted)⑶ Make sure that adjustment for reverse positioner isperformed by increasing/decreasing the input signal.
⑷ Perform operating adjustment in accordance with theprocedures from ltems 6.2 to 6.5, and check with loop
test.

IMPORTANT22The Models EA90A and EA90AC cannot
be compatible with the reverse positioner.
(The positioner does not work even if thewiring is connected in reverse since
diode is mounted in torque motor.)

6.8.1 Switching Procedure⑴ Operate the ﬁltered regulator, and set the
supply pressure (SUP) to zero.
⑵ Turn the A/M switching screw to manual "M"side (clockwise) with minus driver until it stops.
⑶ The air is supplied through the air pipe tosupply side (SUP).
⑷ Operate the ﬁltered regulator, and perform
operation of control valve manually.
⑸ Turn the A/M switching screw to auto "A"side until it contacts with the stopper screw.
⑹ Operate the ﬁltered regulator, and reset tooriginal supply pressure.

IMPORTANT

Never remove the stopper screw.

Model EA91A＆EA90A

7 MAINTENANCE
CAUTIONBe sure to move the Valve Positioner to non-hazardous area
for repairing or maintaining incident to part replacement.

7.1 Periodic Maintenance
Periodic maintenance and check are important in preventing occurrence of non-conformance andextending service life of the positioner. A deﬁnite maintenance program should be established andfollowed using the Periodic Check List shown below as a guide.

Periodic Check List
※Before inspection of each part, check for damage of appearance, abnormal rust, airleakage, etc.

Sliding

Pilot

Pneumatic
Pressure

Check Item

Periodic Check Frequency (Yr.)
1.0

2.0
○

Pressure Gauge

Remarks
Check for presence or absence ofdamage and for accuracy

Restriction (Fixed Restriction)○

Refer to Item 7.2.1

Filter○

Refer to Item 7.2.1

Diaphragm○

Check for wear and tear, Refer to Item 7.2.2

Gasket Packing○

Check for wear and tear, Refer to Item 7.2.2

Nozzle, Flapper○

Check for presence or absence of damage

Supply Air Valve,
Seat for Main Body
Feedback Lever(Sliding Part of Connector Pin)○

Check for presence or absence of damage○

Check for presence or absence ofwear and tearConnector Pin (Transmission Pin)○

Check for presence or absence ofwear and tearSet Spring (Linear Type)○

Check for presence or absence ofwear and tear

Each Bearing (Linear, Cam Types)○

Use Plasti-lube #00 when reassembling※For ﬁltered pressure reducing valve, periodically perform blowing of drain (Guide : approx. 6months) and cleaning of ﬁlter (Guide：approx. 1 year)【Note】 Plasti-lube : Produced by SULFLO INC

23

Model EA91A＆EA90A
7.2 Maintenance Procedure
7.2.1 Restriction and Filter
The restriction of air pipe, clogging and dirt⑻

Reset the supply air pressure to original
pressure. Then, check for leakage from theof ﬁlter in the positioner might cause failure. Clean
the air pipe and the ﬁlter periodically.
⑴ Set supply air pressure at zero.
⑵ Loosen the drain cock of the ﬁltered pressure

gasket and the pilot assembly.
⑼

Align the opening of the pilot cover withoriginal position, and mount the pilot cover.

reducing valve. Then, drain and purge properly.
⑶ Remove the restriction.
⑷ Clean overall restriction by inserting a ∅0.2
mm wire into hole of restriction.

OUT⑸ Remove the ﬁlter of nozzle base. Then, clean

SUP

and purge properly.
⑹ Apply a coating of silicon grease thinly anduniformly when assembling.
⑺ Perform the reversed procedure for reassem-bling. At this point, check for leakage fromSet Screw

restriction.
Never loosen the set screw on the nozzle
base when performing the restriction
IMPORTANT

check. (The gap between ﬂapper andRestricuion

nozzle is adjusted precisely.)

7.2.2 Pilot⑴ Follow the procedure described in Item 7.2.1
for operation of supply air pressure and ﬁlteredpressure reducing valve.
⑵ For pilot assembly, loosen three pan headscrews, and remove the pilot from manifold
after removing the pilot cover.
⑶ Disassemble the pilot. Check for wear andtear in upper and lower diaphragms, and forpresence or absence of damage in supply
air valve and seat of main body.
⑷ At the same time, check for wear and tear ingasket A and B.
⑸ Clean the parts described above andove-rall pilot.

After checking each part, be sure to⑹ Reverse the procedures to reassemble thepilot. At this point, make sure that the oriﬁce
plate is placed at original position.
⑺ Reverse the procedures to mount the pilot
assembly to manifold when removing the pilot
assembly.

24

check by performing the operating test
IMPORTANT

and the loop test.

Model EA91A＆EA90A

8 TROUBLESHOOTING
Following problems and causes are non-conformances expected to encounter in routine operation. Take
following remedy if the non-conformances are encountered.

Troubleshooting Chart

Positioner does not work normally

Positioner does not work

Problem

Cause

Corrective Action

Positioner does notwork normally

Abnormal control valve

Turn manual switching mechanism to "M", adjust
supply air pressure, and check whether control
valve works normally or not. If abnormality ispresent, disassemble control valve.

Excessive vibration incontrol valve

Wear of contacting face
between nozzle and flapper

Replace positioner.

Abnormal response
speed, hunting

Incorrect selection of orifice plate,dislocation of assembling position

Check in accordance with nameplatestuck to pilot cover.

Supply air pressure isout of the standard

Supply air does not servenormally

Check supply air filter regulator,
Check air pipe for leakage.

Leakage in output air pipe

Check air pipe for leakage.

Zero position is dislocated

Apply 50% input signal, and turn zero adjustment knob to check whether air is output.

Manual switching screw is
set to "M" side

Change to "A" side.

Electric wire is disconnected

Check electric lines, and tighten eachwire securely.

Electric line is short-circuited

Remove short-circuited part, and then change
input signal from 50% to between 25% to 75%
to ensure that short-circuiting is absent.

Filter and/or restriction is
cloggedMove flapper with finger, and check whether
output increases or decreases. If output airpressure could not be obtained, clean filter
and /or restriction to remove clogging.

Contacting face between
nozzle and flapper isimproperCheck for contact by inserting seal tapebetween nozzle and flapper. If not outputting, replace pilot.

Noise influences the signal.
Signal itself changes wiggly.

Change the signal wiring to the shield one.
Adjust the gain of the Electro-controller.

Output pressure does
not increase

Valve opening changes
wiggly.

Poor repeatability

Zero position is dislocated

Check each part listed below for looseness, and tighten securely.
○ Looseness in stroke adjustment knob.
○ Prevention of backlash in zero adjustment screw. Looseness in screw.
○ Dislocation of cam.

Retighten and adjust mounted
tight-ened part listed below.

Large hysteresis error. Mounted or tightened part
Poor linearity
is loosened and twistedor○ Backlash and looseness in mountedpart of back lever.
○ Looseness in armature of feedback
spring and balance spring with tightenedparts.
○ Looseness and twist in joint, fit, orconnecting part to transmit force.

Slow response speed

Filter and/or restriction is
clogged, Air leakage from
joint

Clean filter and/or restriction, or retighten
joint part to stop air leakage. If response
speed is still slow, replace pilot.

Hunting exists

Too small capacity of actuator(Be careful if capacity is less than
300cc)

Exchange, orifice plate to V-groove 3 ofstandard orifice plate or No. 2 of orificeplate.

※Since the positioner is to be installed under several conditions, non-conformance that is diﬃcult to predict might occur.
If non-conformance occurs, contact our sales oﬃce or sales agency for purchase.

25Model EA91A＆EA90A

9 REFERENCE INFORMATION
9.1 Predicted Service Life
The predicted service life of each part used in Model EA91A/EA90A Electro-pneumatic Positioner is listed
below. However, since this predicted values will diﬀer depending on the operating temperature, operatingpressure, operating frequency, and operating environment, use this list when performing periodic repair
and periodic maintenance as the reference value.
Therefore, take note that the predicted service life listed below is not assured by MOTOYAMA. The productwill be warranted for one year after delivering this product in principle.

Model : EA91A/EA90A (Predicted Service Life:10 Years)
Main Part Name

Material

Predicted Service
Life (Yr.)

Spare Parts

Remarks

Pressure Gauge

Stainless/C6872T

３−

Pilot Valve

Aluminum Alloy/Rubber with Cloth

５

Presence

Replace packing at replacement.

Restriction

Stainless５

Presence

Replace O-Ring at replacement.

Manual Switching Screw

Stainless５−

NozzleStainless５−

Flapper

Stainless５−

Variety of Spring

Stainless-WP

10−

Cover Packing

NBR

３

−

FilterSintered Metal

３−

Variety of O-Ring

NBR

５Presence

Model EA91A/EA90A
Electro-pneumatic Valve Positioner

Air Filtere Regulator
Output Pressure Outlet

Supply Pressure Outlet

Pilot Valve
Output Pressure Gauge

Supply Air Pressure Gauge

Restriction

Auto / Manual Switching Screw

Feedback Spring
Stroke Adjustment Knob

Zero Adjustment Knob
Terminal Box

Main Body

Conduit Connection

26

Zero
Adjustment Spring

NozzleFlapperModel EA91A＆EA90A
9.2. Dimension of Fitting⑴ Bracket【Note】※1. Actuator Type：The bracket for ♯3800 and ♯3300 can be attached to Model EA91A
electro-pneumatic valve positioner and MR2000 air ﬁlter regulator.
※2. Actuator Type：When attaching the bracket for ♯2800 to MR2000 air ﬁlter regulator,
special brackets shown below are required.

Unit : mm
Mounting Eye for MR2000

Mounting Eye for MR2000

104

140

Mounting Eye for MR2000

232

222

Use backside of left dwg.

Actuator Type : ♯3800, Size:N24 to N33S

Actuator Type : ♯3800, Size:N40

Actuator Type : ♯3800, Size:N40(W/Side Handle)(W/O Side Handle)(W/Side Handle : Common)

For φ330 to φ500

160

190

For φ240 to φ280

210

210

Actuator Type : ♯2800, Size :φ240 to φ500

Actuator Type : ♯2800, Size :φ650(For φ240 to φ280, W/Side Handle : Common)(For φ330 to φ500, W/Side Handle)

Mounting Eye for MR2000

110

84

Bracket for Air Filter Regulator

Mounting Position
for MR2000
196.5

184

Actuator Type : ♯3300

Mounting Position
for MR88

Actuator Type : ♯2900, and ♯3900

Unit : mm20⑵ Feedback Lever

L

Actuator Type

Actuator Size

＃2800

∅240 to ∅330

＃3800

N24 to N33S

＃2800

∅400 to ∅650

＃3800

N40

＃2800

∅400 to ∅650

＃2800

∅240 to ∅330

＃3800

N24 to N33S

＃3300

C20

Lifting RangeL

15 to 38187

15 to 65247

70 to 130357

5 to 10

165

12.7

27

Model EA91A＆EA90A（3）Connector Arm

Unit : mm

W

90

80

52

15 to 38 1308052∅400 to ∅500S

15 to 65 183

110

70

∅500

70 to 100 293

100

80

∅500SH-BL

15 to 65 183

110

110

∅500SH-BL

70 to 100 293

100

90

∅650

15 to 65 191

110

130

∅650

70 to 130 298

100

140

W

∅270

75

Lifting Range

L

H

W

N24 to N33S

５ to 10

56

90

38

N24 to N33S

15 to 38

81

90

38

N33L to N40

15 to 65

96

90

45
50

Lift 15 to 65mm

B

∅240 to ∅280

＃3800

N24 to ∅N40

＃3300

C20

＃2800

∅330 to ∅650

A

Actuator Size

＃2800（5）Stem Clamp

L

B

Actuator Type

L

40
55

（6）Spacer Bolt

Actuator Type Actuator Size
＃2800

∅240 to ∅330

＃3800

N24 to N33S

＃2800

∅400 to ∅500

＃3800

N40

＃2800

∅650

（7）Spacer

Applied Valve Type

Ｌ1

Ｌ2

＃92
（−Ａ）

95

22

＃16B
（Ⅴ）
、
＃11-1M

85

24

∅16

Bracket Side Screw Thread

28

L1（8）Joint

78

28

20

Actuator Type : ＃3300

Actuator Size

（4）Connector Pin

L2

W

∅200
114

L

Lift 5 to10mm

Actuator Size

Actuator Type : ＃3800

H

20
L

Actuator Type : ＃3400

41∅240 to ∅330

H

20

W

５ to 10H

70∅240 to ∅330

L

20

Lifting Range

W

L

Actuator Size

32

H

20

W

Actuator Type : ＃2800

A

B

20

42

23.5

54

28

65

Model EA91A＆EA90A

FOREWORD
Thank you very much for purchasing our Model EA91A/EA90A Electro-pneumatic
Valve Positioner. Take fully notice that the items described below to use this valve
positioner safely and correctly.

1 General Information⑴

This Instruction Manual describes the basic recommended procedures for opera-ting the Model EA91A/EA90A Electro-pneumatic Valve Positioner. Thoroughly readand understand all descriptions in this manual before operation. This Instruction
Manual should always be referred prior to any operations.
⑵

This product is mounted to a control valve as dedicated equipment. Read andfollow all individual procedures in this instruction manual with the instruction manualof control valve when working and operating this product mounted to the control
valve.
⑶

As the result of studying and improving this product without notice, thespeciﬁcations, dimensions, adjustments, illustrations, and other items included inthis manual might be diﬀerent in details. For any questions about the delivered
product or this instruction manual, contact MOTOYAMA sales oﬃce or sales
agency for purchase before operation.

2

Safety Information
To handle this product safely, the symbol marks and signal words shown below
are used in this instruction manual to alert risk as required. The contents of symbol
mark and signal word are described below.
Symbol Mark &Signal Word

Description
This mark with this signal is used when the possibility of

WARNING

death or serious injury to user is assumed if handling thisproduct incorrectly.
This mark with this signal is used when the possibility oflight injury or middle injury to user, or property damage

CAUTIONis assumed if handling this product incorrectly.
This mark and signal are used to comply the instructions

IMPORTANT

to prevent damage of this product or malfunction.

29

Bulletin No.MIE-B6104P

http://www.motoyama-cp.co.jp
本 社 工 場

Main Office & Factory

TEL（022）344-4511（代表） / FAX（022）344-4522
E-mail : info@motoyama-cp.co.jp
5-2, Ohira Aza Kameoka, Ohira-mura, Kurokawa-gun, Miyagi, 981-3697, Japan
TEL +81-22-344-4511 / FAX +81-22-344-4522
E-mail : info-overseas@motoyama-cp.co.jp〒981-3697 宮城県黒川郡大衡村大衡字亀岡５－２●販売・サービスネットワーク

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TEL（044）381-8770（代表） FAX（044）381-8772

大

阪

支

店

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TEL（06）6535-8111（代表） FAX（06）6535-8655

国

際

営

業

部

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TEL（044）381-8771

FAX（044）381-8773

札

幌

営

業

所

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リバティタウンP棟101号

TEL（011）766-1520

FAX（011）766-1521

東

北

営

業

所

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TEL（022）344-1761

FAX（022）344-1762

上

越

営

業

所

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TEL（025）542-5151

FAX（025）542-5152

関

東

営

業

所

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TEL（0436）21-4400

FAX（0436）21-3540

静

岡

営

業

所

〒422-8033 静岡市駿河区登呂4丁目28-5

TEL（054）269-5377

FAX（054）237-5855

名 古 屋 営 業 所〒481-0012 愛知県北名古屋市久地野安田36番地

TEL（0568）26-6681

FAX（0568）26-6631

水〒481-0012 岡山県倉敷市二日市358

TEL（086）486-3381

FAX（086）486-3382

阪 神 サー ビ スセンター〒560-0894 大阪府豊中市勝部2丁目18-3

TEL（06）6854-7511

FAX（06）6854-7512

姫

路

出

張

所

〒672-8014 兵庫県姫路市東山276番地1

TEL（079）263-8640

FAX（079）246-2130

徳

山

営

業

所

〒745-0861 山口県周南市新地1丁目6-11

TEL（0834）21-5012

FAX（0834）31-0450

四

国

営

業

所

〒792-0896 愛媛県新居浜市阿島1丁目6-26

TEL（0897）47-8993

FAX（0897）47-8995

大

分

営

業

所

〒870-0108 大分市大字三佐字山ノ神980-1

TEL（097）527-3704

FAX（097）522-2352

TEL +86-411-6589-1277

FAX +86-411-6589-1278

大 衡 サービスセンター
上 越 サービスセンター
千 葉 サービスセンター

中 部 サービスセンター

島

営

業

所

周 南 サービスセンター
新 居 浜 サービスセンター
大 分 サービスセンター●海外関連会社本山阀门（大連）有限公司 〒116601 中国 遼寧省大連市金州新区港興大街 39 号 14-7
●海外販売代理店

中国、韓国、台湾、シンガポール、インドネシア、マレーシア、サウジアラビア●SALES AND SUPPORT NETWORK

Overseas Marketing & Sales Dept. : 11th Floor, Clie Kawasaki, 10-5, Ekimae-honcho, Kawasaki-ku, Kawasaki-city, Kanagawa, 210-0007 Japan
TEL: +81-44-381-8771
FAX : +81-44-381-8773
Domestic Sales Branches : Tokyo, Osaka, Sapporo, Tohoku, Joetsu, Kanto, Shizuoka, Nagoya, Hanshin, Tokuyama, Shikoku, Oita

●OVERSEAS AFFILIATED COMPANY

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Gangxing Street 39-14-7, Jinzhou New District, Dalian-city, 116601 China

TEL: +86-411-6589-1277

FAX: +86-411-6589-1278●OVERSEAS NETWORK

China, Korea, Taiwan, Singapore, Indonesia, Malaysia, Saudi Arabia◆当社は保証期間を原則として製品納入後１年としています。
◆The product will be warranted for one year after delivering this product in principle.
■本取扱説明書の記載内容は、商品の改良等のため予告なく変更することがありますので予めご了承下さい。
■MOTOYAMA is continuously improving and upgrading its product design, specifications and/or dimensions. Information included herein issubject to change without notice.

■本取扱説明書は正しい情報の提供を目的としたものであり、本製品の市場性または適合性の保証を証明するものではありません。
■This instruction manual is supplied for information purpose only and should not be considered certified marketability and conformabilityof this product.

202402 MSP