AMPLIFIER LOADED TYPE DIRECTIONAL AND FLOW CONTROL VALVE WITH DIGITAL SETTING DEVICE（EHD3A）■Features
1. The valve enables easy 2-speed control and shockless control.
2. A digital setting device is used for 2-speed and shockless control allowing excellent
repeatability.
3. The digital setting device is detachable, making it possible to adjust the setting
while observing the actuator closely.
4. The throttle can be selected from among the meter-in throttle, meter-out throttle
and meter-in/meter-out throttle.
5. The mounting dimensions have interchangeability with conventional size 025 andsize 03 solenoid-operated directional valves.

■Application examples
1. 2-speed and shockless control for a transfer unit
2. Shockless control in reversing the direction of operation of a cylinder
3. Shockless control for a single-acting cylinder
4. Remote / proportional control■Cautions on use

Caution● Since the valve incorporates precision electronic parts, pay attention tothe following points when handing the valve.
1. Do not stand on the valve.
2. Do not drop or apply shock to the valve or setting device.
3. Do not lift up the valve by the cable of the setting device.
4. Be sure to tighten the screws of the lid of the amplifier and the setting
device.

SOLa input

GSOLb input

5. The valve is designed to have adequate environmental resistance against
vibration, electric noise, water, etc. However, it is advisable to consult us if
the valve is installed in especially harsh conditions such as in a vehicle.

■Cautions on wiring
1. The power cable must be larger than 0.75 ㎜2.
2. The tightening torque of the screws on the terminal block should be 0.8
N-m or less. Screws on terminals where cables are not connected mustalso be tightened to prevent them falling.
3. Since internal control circuits may be damaged if power cables areconnected incorrectly, check that the power cable connections are correct
before turning on the power.
4. ① +PT terminal
The +PT terminal is the voltage output terminal for an external settingdevice. Therefore, do not apply voltage to this terminal.
② Terminal INa/INb
When the valve is used with the setting device mounted, the output of thesetting device is connected to terminals INa and INb. Therefore, do not
apply voltage to these terminals.

5. The amplifier is able to operate correctly under the voltage range indicatedbelow.
Confirm that the valve is connected to the correct power supply before
turning on the power.

Voltage: DC21 to 28 V
Current: 1.3 A or larger
6. Do not leave metallic objects in the amplifier.

G−9

CURRENT CONTROLLED TYPE CONTROL VALVES

1. Do not directly spray organic solvent (ether solution, thinner, etc.) onto theamplifier or the setting device of the valve. When coating the valve withpaint, be sure to mask these parts.
2. The applicable fluid is equivalent to hydraulic oil ISO VG32 to VG56. The
permissible dynamic viscosity is 15 to 300 ㎜2/s.
3. To achieve stable characteristics, keep the solenoid immersed in the oil.
For this purpose, sink the R port pipe into the fluid completely or install thecheck valve at the R port to prevent entry of air into the R port.

4. When using the valve as a current-controlled valve without mounting thesetting device, avoid simultaneous input of the SOLa and SOLb signals. Ifeither of the solenoids is to be turned ON immediately after turning OFF
the other signal, allow an interval of at least 0.1 seconds between turning
OFF and turning ON. When the setting device is mounted, smoothshockless control is possible without providing an interval between theseevents.
0.1 sec■Description of the model designation

EHD３AｰDｰF３０ｰBCAｰ０２５AｰS１D

Current-controlled type directionaland flow control valve
Max. operating pressure 3: 25 MPa
Valve with amplifier
Drive method
D: Direct spool drive
Throttle method V: Meter-in/meter-out (NOTE 1)F: Meter-out
Y: Meter-in
Control flow 30: 30 L/min
60: 60 L/min
Spool type
Nominal size 025A: Size 025
03A: Size 03

Type D: Contact input type A: Analog input type
Cable length 1: 0.3 m 2: 1 m
Setting device No code: Without setting device S: With setting device

V**ｰBCAY**ｰBCA

F**ｰBCAY**ｰBGANOTE: The opening area of meter-in/meter-out throttle is “P →A, P→B > B→R, B→A”, to give priority
to the meter-in throttle.

■General specifications
Size 025

Nominal size

25Max. Operating pressure

MPa

Flow adjustment range

L/min

0.5 to 30

MPa7Permissible back pressureAmplifier

Power supply(for control)

Power supply
for external setting unit

CURRENT CONTROLLED TYPE CONTROL VALVES

Settingdevice

1 to 60
16Voltage

V

DC24 (DC21 to 28)

Current

A

1.3 (at DC24 V)

VoltageV

DC0 to 5kΩ

10Voltage

V

DC5.6

Load current

mA

15

Analog input(without setting device) Input resistance

GSize 03

1/100

Flow setting resolution (F1, F2)

0 to 10 (NOTE 1)

Switching time adjustment range (t1 to t3) sec.
Switching time adjustment resolution

Switching signalTime constant control, Constant slope control (selectable) (NOTE 2)

ON voltage

VDC12 to 32

OFF voltage

V

DC0 to 8CurrentmA

10/1 contact point
Bi-directional photocoupler, sink/source common use

Input interface
Analog input(analog input type)

0.05

sec.

Switching time control mode

VoltageV

DC0 to 5

Input resistancekΩ

20

m0.3, 1

Cable length℃

Operating temperature range

0 to 60
JIS B 1176M5×45

Accessories (4 bolts)
MasskgSolenoid model

Acceleration time constant control

JIS B 1176M8×60

2.7

6.5

LHSｰM46T0

SDM3ｰ03ｰD

Acceleration slope constant control

Acceleration time t does not change evenwhen flow Q is changed.

Acceleration slope θ does not change evenwhen flow Q is changed.

■Environmental resistance specifications
Noise resistance1000 Vp-p (pulse width: 1 µs)

Withstanding voltage

AC1500 V, 1 min. (across input terminal and valve body)Insulation resistance

DC500 V, 10 MΩ or larger (across input terminal and valve body)Protection

IP55

Vibration
ResistanceConstant vibration

Amplitude 4 mm, Frequency 30 Hz 69 m/s2 {7G} JIS C0911

Sweep

Amplitude 1.5 mm, Frequency 10 to 55 Hz/min 89 m/2 {9G} JIS C0911

Shock resistance

G−102147m/s｛15G｝
11 ms

NOTE 1: In acceleration slope
constant control, the time
to be set corresponds to100% output.
NOTE 2: Acceleration time
constant control andacceleration slope
constant control are
performed in the mannershown below.

■Performance curve
Current - Flow characteristics
Size 025

Size 03
Flow

Flow

Input current (A)Input current (A)■Outside dimensions
EHD3AｰDｰ***ｰ***ｰ025AｰS**
Valve mounting dimensions

40.5
30.2
21.5
12.7

Setting unit

G4ｰJISB2401ｰ1AP9(O-ring)

137Cable

8Subplates to be used

4563
217.6

4ｰM548Mass: ２.7㎏

SHD025ｰ02T1A
SHD025ｰ03T1A
SHD025ｰ02T3A
SHD025ｰ03T3A

EHD3AｰDｰ***ｰ***ｰ03AｰS**

14

Valve mounting dimensions
54
50.8
37.3
27
16.7
3.2
P143

B

A
RR

6.4
21.4
32.5
46
11

Setting device clamp fitting

5ｰJISB2401ｰ1BP12
Setting unit (O-ring)

Amplifier

Cable inlet G1/2

150.2

Cable

11

Subplates to be used
82316

4ｰM868Mass: 6.5㎏

SHD03ｰ04T1A
SHD03ｰ06T1A
SHD03ｰ04T3
SHD03ｰ06T3

G−11

CURRENT CONTROLLED TYPE CONTROL VALVES

Cable inlet G1/2BP

143
Amplifier

25.9
31
31.75

7RA

0.75

105.1
15.5

Setting device clamp fitting

■Control with digital setting device
1. The digital setting device is classified into two types according to the typeof input, namely the contact input type and the analog input type.
2. Set values can be altered during operation.
3. The setting resolution is 1/100, facilitating fine adjustments.

Parameter indicator
Indicates successive parameternames in the order F1 → F2 → t1 →t2 → t3 when the parameter key ispressed repeatedly.

Set value indicator

Parameter key

Displays the set value in the
program mode and the active
solenoid in the run mode.
When the UP and DOWN keys arepressed simultaneously, this unit
displays the output data.

Once this key has been pressed themode changes to the program mode.
After that, pressing the parameter key
selects the parameter in the order F1→ F2 → t1 → t2 → t3. The modechanges to the operation mode
automatically if the key is notoperated.

Up / Down keys
Increases / decreases theparameter setting value in theprogram mode.

Solenoid selection indicator
Indicates the selected solenoid
when inputting a parameter.

Solenoid selection switch

Time control mode selectionswitch

Allows selection of SOLa and SOLb
when inputting a parameter.

G

Allows the selection of the time
constant control mode or the slope
constant control mode.

CURRENT CONTROLLED TYPE CONTROL VALVES

Operation procedure(For details, refer to the Instruction Manual.)
1. Select the control mode with the time control mode
selection switch
2. Select SOLa or SOLb with the solenoid selection switch
3. Select the parameter with the parameter key
4. Set the value with the UP and DOWN keys.

■Setting examples
Contact Input type
1. Acceleration time constant control and acceleration slope constant control
can be selected.
2. Since SOLa and SOLb can be controlled independently using contact
commands, cylinder operation can be set independently for advance andretraction (upward and downward movements). Flow for high-speed
operation and low-speed operation, and acceleration / deceleration / halttime can be set.
3. Shockless positioning control is possible using contact commands of the
programmable controller and relays.

Parameter indicator

Flow patternt2

t1

SOLat3

Wiring diagram

Solenoid selection switch

F1Time control mode selection switch

F2FlowCylinder

F2F1SOLbt1
CR1Switchingsignal

CR2
CR3CR4

Parameter key
Solenoid selection indicator

t2t3

ONON

DOWN KeyON
ON

CR1
CR2
CR3
CR4

UP KeySet value indicator
Control power DC24 VG−12

Analog Input Type1. Acceleration slope constant control is possible.
2. Flow can be controlled in proportion to analog voltage with acceleration/deceleration.
3. Multi-step control is possible using a joy stick or external trimmers.
Parameter indicator

Flow pattern

Wiring diagram

Parameter key
Solenoid selection indicatorFlowSOLa

θ1
θ1F1F2

θ2F3Solenoid selection switch
θ3SOLbV1VaV2

θ1 F1F2θ1F3Time control mode selection switch

θ3θ2V3Analog input
V1VbSwitchingsignal

V2V3DOWN Key
CR1ONCR1Va

CR3

UP KeyVbSet value indicator
ONCR3Control power DC24 V■Control without digital setting device
Control in various patterns is possible in the same manner as for the EHD 3
type current-controlled type directional / flow control valve by inputting acommand voltage from an external device such as a computer, joy stick orprogram setting device.

Computer

Joy stick

Program setting device

GCURRENT CONTROLLED TYPE CONTROL VALVES

Command voltage■Wiring diagram
The figure below shows the cable connection for controlling the operation with a command voltage.
Power output terminalfor external setting unit (+PT)

SOLb analog input terminal (INb)

SOLa analog input terminal (INa)1) Using an external trimmer

Control power DC24 V

2) Using an external analog voltage

Wiring method

G−13