MS61A-RA

Manostar switch
List ofproducts

WO81

MS61A-RA
Small-size fine differential pressure switch

RoHS• Small-size/lightweight type that can be installed anywhere you likeWO71• The operating pressure can be set only by adjusting the scale knob with oneaction.

FR51A• Unique mechanism less subject to abnormal high pressure inrush• High-performance silicone rubber diaphragm with small hysteresis

MS99

MS99S

MS61A-RA

QDP33

EMD8A

EMD7

EMT1

EMTGP1MS61A-RA

EMT1H

With built-in lead switch(single-pole normally open sealed type)

EMT6*Model MS61A-RA, which came to be resold in September 2019, is not compliant with the UL standard.

EMP5A

EMRT1

HWS15A

Accessories
Application

Precautions
Maintenance<Main application fields>• Part of semiconductor
manufacturing equipment• Negative pressure for dust
collector/differential pressure of airconditioner• Filter pressure loss management• Precision machine manufacturingline• General factory management
equipment

MS61A

LPressure range code

Ｖ120

Ｄ －ＲＡ (Example)

Contactspecification<Usage>• Measurement of internal pressure ofindoor device• Detection of clogging of air filter• Measurement of clogging of bugfilter• Measurement of dynamic pressure
at ventilation/exhaust device• Room pressure measurement in aclean room*(Refer to pages 114 to 117)

47

Product codeUnit
Range
Base
Scalesetting◆When making an inquiry or placing an order, specify the above product code.

normally open－ＲＡ Single-polesealed type

ＤＥ

PakPa

Maximum scale value

ＶFor vinyl pipe

ＨＬ

Upper limit setting
Lower limit setting

MS61A-RA

Manostar switch
MS61A-RA

List ofproducts

Specifications
ModelWO81
Instrument for upper limit setting

Instrument for lower limit setting

MS61AHVMS61ALV

Pressure unit

Pa, kPa

Pressure measurement
methodDifferential pressure method

Pressure-receiving
element

Diaphragm (silicone rubber)

Measured gas

Air and noncorrosive gas (liquid cannot be measured)

Pressure setting method

Setting by knob with scale

Standard mounting
orientation

Mounted at arbitrary angle between horizontal and uprightOperating ambient
temperature−10°C to +50°C (no freezing allowed)

Operating ambient
humidity

90% RH or below (no condensation allowed)

Instrument bodywithstanding pressure

100 kPa (refer to page 118)

Withstanding pressureof pressure-receiving
element

20 kPa (refer to page 118)

Exterior material

Polyamide

WO71

Durable vibration

5 to 10 Hz, amplitude of 10 mm,
10 to 50 Hz, acceleration of 39 m/s2 (two hours each for three axialdirections)

Durable impact

100 m/s2 (six times each for three axial directions)

Insulation resistance

Between terminal and case
20 MΩ or higher (500 V DC megger)

Withstand voltage

Between terminal and case
500 V AC 50/60 Hz for one minuteCompatible pipe

Vinyl pipe or rubber pipe (inner diameter of 4 mm)Terminal screw size

M3.5

Base polarity

Indicating high-pressure side and low-pressure side with “H” and “L” marks,
respectively, at the piping connection base part.

MassApprox. 140 g

Mounting screw size

M4

FR51A

MS99

outer diameter of φ8 or below

MS99S

MS61A-RA

Pressure range code

Scale setting accuracy(at 20°C)

Pressure range

Maximum operatingpressure difference

120 D*

20–120 Pa±5.0 Pa37.5 Pa

300 D

50–300 Pa±15 Pa

60 Pa

600 D

100–600 Pa±25 Pa120 Pa

1.2 E

0.2–1.2 kPa±0.050 kPa

0.240 kPa

3E

0.5–3 kPa

±0.15 kPa

0.60 kPa

6E

1–6 kPa±0.30 kPa1.20 kPa*Instrument for upper limit setting cannot be manufactured.
◆If you desire to procure a model with a mounting orientation other than above, such as downward and horizontal mounting and mounting
orientation 135°, let us know in advance because adjustment needs to be made before shipment from the factory.
◆For use environment, refer to page 118.

Opening/closing capability
Contact typeSpecifications

RatingOpening/closing
voltage

Opening/closing
current

Opening/closing
powerSingle-pole normallyopen sealed typeContact configuration: SPST (Single Pole
Single Throw) N.O.
Electric service life: 100,000 times ormore
Contact structure: Lead switch

0.1 A–30 V DC

100 V DC(maximum)

0.25 A DC(maximum)

10 W DC(maximum)！
CautionThe product may malfunction from the influence of the external magnetic field. Install the product at a sufficient distance from the circuit withhigh voltage and large current, apply a magnetism shield as necessary, and use the product after sufficiently checking its operation.

QDP33

EMD8A

EMD7

EMT1

EMTGP1

EMT1H

EMT6

EMP5A

EMRT1

HWS15AAccessories
Application

Precautions
Maintenance48

MS61A-RA

Manostar switch
List ofproducts

WO81

MS61A-RAExternal dimension drawing
MS61A-RA w/built-in lead switch (single-pole normally open sealed type)îĳ0RXQWLQJKROH

WO71

COM.
10WHUPLQDOVFUHZZWHUPLQDOFRYHU

FR51A.QREFRYHU
0RXQWLQJ
VFUHZ'LIIHUHQWLDOSUHVVXUH
LQFUHDVHV&RQWDFWFRQILJXUDWLRQ

80

90

２MS99

N.O.
2îĳ KROH
RU0WDS

１1DPH
SODWH
80±0.3MS99S

QDP33L

φ5.5

H

MS61A-RA4577441573DQHOFXWWLQJ

EMD8A

Mounting orientation and range
EMD77KHVZLWFKFDQEHPRXQWHGDWDUELWUDU\DQJOHEHWZHHQKRUL]RQWDODQGXSULJKW)RURWKHUPRXQWLQJRULHQWDWLRQVLWLVQHFHVVDU\WRVSHFLI\WKHRULHQWDWLRQDWWKHWLPHRIRUGHUSODFHPHQW
8SULJKWSODQH

EMT110°EMTGP17KHLQVWUXPHQWFDQEHPRXQWHG
RQWKHPRXQWLQJSDQHOLQDQ
DUELWUDU\PDQQHU%HWZHHQKRUL]

90°

5°

LJKW $UELWUDQGXSU
U\PDODRX
RQW

132WKHU

EMT1H

180°

0°

EMT6J
QWLQ

90°

EMP5A+RUL]RQWDO
SODQH

10゜

EMRT1

HWS15A

Overview of structure1

Number3

Accessories
Application

4

Precautions
Maintenance

Name

1

Microswitch2

Diaphragm

3

Cover

4

Housing5

BaseHigh-pressure side baseLow-pressure side base！
549

2

CautionTerminal screw tightening torque: 0.7 to 1.0 N·m
Do not tighten with a greater force than necessary because doing sobreaks the instrument body.

MS61A-RA

Manostar switch
MS61A-RA

List ofproducts

Accessories dedicated to MS61ARoHSKnob cover set

WO81

Terminal cover(Auxiliary item)

WO71

FR51A
This is to protect the scale knob for
setting use from inadvertent turning aftersetting.
Item number

TCVRA-61

Material

Brass/steel

MS99
Item number

TCA-61A

Material

Polycarbonate

MS99S

MS61A-RA

Configuration of switch contact○ The contact configuration of this instrument is as shown on the right.

COM.
1○ When no differential pressure (pressure) is applied to the instrument, the section

N.O.
2

between COM. (1) and N.O. (2) is open.

Differential
pressure
increases.

○ When the differential pressure increases and reaches the set pressure, the contact isswitched and the section between COM. (1) and N.O. (2) turns to be closed.

EMD8A
Set
pressure
Operatingpressuredifference

Upper limit setting and lower limit settingpressure (pressure) applied to the instrument has increased from zero is referred to as
the set pressure.

Resetpressure

EMT1
TimeThen, the pressure at which the contact has returned to the former state as thedifferential pressure has decreased from the use condition at a pressure greater than theEMD7(dead band)

Differential
pressure

The pressure at which the electric contact of the switch is triggered as the differential

QDP33

Figure for explanation ofoperating pressure difference

set pressure, and the electric contact has been triggered is referred to as the reset pressure.
The set pressure and reset pressure mentioned above are not the same values, but are slightly different from each other. ThisEMTGP1

EMT1H

difference is referred to as the operating pressure difference (dead band).
This instrument has two variations: one with the scale of setting dial set to the set pressure; and the other with the scale set toEMT6

the reset pressure.
This instrument with the scale set to the set pressure is referred to as the instrument for upper limit setting, and the instrumentwith the scale set to the reset pressure is referred to as the instrument for lower limit setting.
When the setting pressure is set to 100 Pa in the pressure range of 50 to 300 Pa for example (operating pressure difference isassumed to be 60 Pa)
Scale setting

Setting dial scale adjustment

Contact action

Instrument for upperlimit setting

Adjustment is made by means ofset pressure.

When the differential pressure increases, the section between N.O. (2) andCOM. (1) closes at 100 Pa. Then, when the differential pressure decreases, thesection between N.O. (2) and COM. (1) opens at 40 Pa.

Instrument for lower
limit setting

Adjustment is made by means ofreset pressure.

When the differential pressure increases, the section between N.O. (2) andCOM. (1) closes at 160 Pa. Then, when the differential pressure decreases, thesection between N.O. (2) and COM. (1) opens at 100 Pa.

！
Caution

It is not possible to change from the upper limit setting to the lower limit setting and vice versa.

EMP5A

EMRT1

HWS15A

Accessories
Application

Precautions
Maintenance50

Warranty■Warranty period
The warranty period for our product is one (1) year from delivery to the location specified by the orderer who makes a direct transaction
with us.

■Scope of warranty
If any failure or defect attributable to us becomes clear during the above warranty period, we will repair the product or supply asubstitute product free of charge. However, even during the warranty period, we will exclude the product from the scope of the warranty
if the failure or defect corresponds to any of the following:(1) The failure or defect was caused by an unreasonable condition, environment, handling, or usage not mentioned in theinstruction manual, specifications, and our product catalog.
(2) The failure or defect was caused by a factor other than our product.
(3) The failure or defect was caused by a modification or repair conducted by a party other than us.
(4) The failure or defect was caused by an event that could not be foreseen at the scientific and technical levels at the time ofproduct shipment from us.
(5) The failure or defect was caused by an external factor not attributable to us, such as acts of God and disasters.
Please note that the warranty mentioned here means the warranty for our individual product, and damage provoked by a failure or
defect of the product is excluded from the scope of the warranty.
*This warranty is valid only in Japan.

Application and usage
Our products are designed and manufactured as general-purpose instruments for general industries.
Therefore, our products are not intended for the following uses, and our products used in such a manner are outside the scope ofapplication.
(1) Equipment that is anticipated to greatly affect lives and properties, such as nuclear power generation, aviation, railways, marine
vessels, vehicles, and medical devices(2) Utilities that include electricity, gas, and service water(3) Use in outdoor locations and under similar conditions or environments other than those stipulated in the instruction manual(4) Usage to which considerable safety consideration and attention equivalent to (1) and (2) above need to be given

Service■Scope of service
Because the product price does not include service expenses, such as the dispatch of engineers, we will separately charge for theexpenses in the following cases:(1) Instruction for installation and adjustment and a witnessed test run(2) Maintenance inspection, adjustments, and repairs(3) Technical guidance and technical education(4) Witnessed inspections of products at our factory<<Note>> The product specifications and information in this catalog are subject to change without prior notice for product improvement orother reasons.

●For order placement, contactGeneral
agent

Manostar Shop Co., Ltd.

1-2-3 Nishishiriike-cho, Nagata-ku, Kobe City, Hyogo 653-0031
TEL. +81-78-621-7000 FAX. +81-78-621-7788

Manufacturer

Yamamoto Electric Works Co., Ltd.

1-2-3 Nishishiriike-cho, Nagata-ku, Kobe City, Hyogo 653-0031
TEL. +81-78-631-6000 FAX. +81-78-631-6020

SEPTEMBER 2021 YAMAMOTO ELECTRIC WORKS CO., LTD., JAPAN