YUKEN KOGYO ELDFG-01EH 10 Series User manual

Instruction Manual
ELDFG-*EH Series
Direct Operated and High Response Type
Proportional Electro-Hydraulic
Directional and Flow Control Valves
Model: ELDFG-01EH-*-*-*-*-*-10
Model: ELDFG-03EH-*-*-*-*-*-10
- To ensure safe and correct use of the product -
●To ensure proper handling of the product, read this manual thoroughly before use.
●Be sure to follow the instructions described in the Safety Precautions section of this manual.
●Keep this manual at hand for future reference.
●When creating instruction manuals for systems equipped with the product, be sure to reflect
the contents of this manual in such documents.
YUKEN KOGYO CO., LTD.
Doc. No. Pub. EM-1359
Date of Issue December 20, 2013
Public Relations Group,
Products Publicity Section,
Sales Administration Department

EM-1359
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About This Manual
●Some figures and illustrations in this manual are simplified and may not be an exact
representation of the product.
●The contents of this manual are subject to change without prior notice as improvements are
made to the product.
●Although this manual has been prepared with great care, please contact the place of
purchase or our customer support if you find any ambiguous explanations, errors, or
omissions.
●If there are missing pages or erratic pagination in this manual, please contact our customer
support. We will replace the manual.
●Reprint, reproduction, or modification of this manual without the permission of YUKEN
KOGYO CO., LTD. is prohibited.

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■Safety Precautions
●This manual is intended for users of the product with basic knowledge of hydraulics (who
are at least equivalent to a class-2 hydraulic system control engineer or who have
received technical training from YUKEN KOGYO).
●The product should be handled by users with knowledge equivalent to that stated above
or under the supervision of such personnel.
●Be sure to provide end-users with the instructions, warnings, and cautions described in
this manual.
●Be sure to attach this manual when transferring or reselling the product.
Safety precautions in this manual are classified into three levels: “DANGER”, “WARNING”, and
“CAUTION”. Be sure to read and understand the safety precautions before reading the main
body of this manual.
Symbols and definitions for safety precautions in this manual are as follows.
Symbols and definitions for safety precautions in this manual are as follows.
Ignoring safety precautions labeled “CAUTION” may result in serious consequences depending
on the situation. Regardless of their classification, all safety precautions contain important
instructions. Be sure to follow them.
YUKEN KOGYO CO., LTD. assumes no liability for any accident or damage arising from the use
or operation of the product in a manner other than specified in this manual.
Indicates an imminent danger that is very likely to cause death or
severe injury if the instructions are ignored.
Indicates a potential danger that may cause death or severe injury if
the instructions are ignored.
Indicates a potential danger that may cause injury or property
damage if the instructions are ignored.
DANGER
WARNING
CAUTION

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Always follow the safety precautions.
Wirin
g
location
Never use the product in an explosive
atmosphere where flammable gases or
explosives are handled. Doing so may
result in a fatal accident, such as fire or
explosion.
Foreign matter in hydraulic fluid may result
in malfunction of the product. Keep
hydraulic fluid clean (NAS 1638 class 10 or
better).
When handling the valve, pay attention not
to apply tension to the cable. Doing so
may cause malfunction due to cable
breakage.
The connector is not included with the valve.
Wire the valve correctly by using the
specified standard connector and referring
to the instructions for the connector. For
the use of YUKEN’s connector TK290457-1,
see the ”Wiring” section of this manual.
Never touch the connector while the power
is on. Doing so may cause electric shock,
resulting in a fatal accident.
Do not modify the product. Doing so may
prevent the product from achieving the
design performance and impair safe
o
p
eration.
Do not step on or put any heavy object on
the product. Doing so may result in
damage to the product/equipment or injury
from collapse/falling.
Valve characteristics may vary depending
on the load pressure and fluid temperature.
Make adjustments so that the valve can
accelerate, decelerate, and stop safely
across the entire range of operating
pressures and fluid temperatures.
Make sure of correct wiring!
Do not apply load to the cable.
DANGER
WARNING
CAUTION
Cable

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Table of Contents
1. Introduction
1.1 Intended users of the product························································· 5
1.2 Intended purpose ··········································································· 5
1.3 Product check ················································································ 5
2. About the product
2.1 Model number designation ····························································· 6
2.2 Specifications ················································································· 6 - 7
2.3 External dimensions/valve mounting surface dimensions ·············· 8 - 9
2.4 Fail-safe function ············································································10
2.5 Electrical specifications ·································································· 10
3. Valve installation
3.1 Valve mounting surface dimensions ··············································· 11
3.2 Required tools ················································································ 11
3.3 Check of the valve mounting surface ············································· 11
3.4 Mounting position ··········································································· 11
3.5 Installation ······················································································ 12
4. Wiring
4.1 Recommended cable ····································································· 13
4.2 Connection between the cable and the connector·························· 14
5. On-board amplifier
5.1 Appearance of the on-board amplifier ············································ 15
5.2 Wiring ····························································································· 15 - 16
5.3 Block diagram ················································································ 16
5.4 Description of signals ····································································· 17
5.5 In the event of valve malfunction···················································· 17
6. Operating the valve
6.1 Adjustment ····················································································· 18
6.2 Operating environment··································································· 18
6.3 Hydraulic fluid················································································· 19
7. Maintenance ····································································· 19
8. Storage of unused valves ······················································· 20
9. Disposal ············································································ 20
10. Customer service ··························································· 20

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1. Introduction
1.1 Intended users of the product
The product should be handled by users with basic knowledge of hydraulics and electrics (who
are at least equivalent to a class-2 hydraulic system control engineer, who have received
technical training from YUKEN KOGYO, or who can fully understand the contents of this
manual) or under the supervision of such personnel.
1.2 Intended purpose
The valves are closed loop, high response type proportional electro-hydraulic directional and
flow control valves with OBE (on-board electronics). With closed loop control based on a
combination of newly developed compact, powerful solenoids and a LVDT for spool position
detection, the valves provide high response, high accuracy, and high reliability equivalent to
those of simple servo valves. The spool type 3C2L is suitable for position control (2%
overlap).
1.3 Product check
Check the following points upon delivery of the product.
If any questions or problems arise, please contact the place of purchase or our local customer
support.
●Check that the model is correct.
Check the model number marked on the nameplate.
●Check for any damage to the product and/or loose screws.
●Check that all accessories are included.
1) Port O-rings (attached to Ports P, A, B, and T on the valve mounting surface)
Valve Model Number Ports P, A, B, and T Qty.
ELDFG-01EH AS568-012(NBR, Hs90) 4
ELDFG-03EH AS568-014(NBR, Hs90) 5
For phosphate ester type fluids, special seals (fluororubber) are required.
2) Valve mounting bolts
Valve Model Number Valve Mounting Bolt Qty.
ELDFG-01EH M5 × 45L 4
ELDFG-03EH M6 × 35L 4
Note) The connector is separately available. Use a 6 + PE connector [EN175201 Part
804]. When using YUKEN’s connector, place your order by specifying the
following parts number.
YUKEN parts number: TK290457-1
Nameplate
ELDFG-01EH ELDFG-03EH

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2. About the product
2.1 Model number designation
*1. The spool in the neutral position is shown.
*2. Phosphate ester type fluids are also supported. When phosphate ester type fluids are used, prefix “F-” to the model
number because the special seals (fluororubber) are required to be used.
2.2 Specifications
ELDFG-01EH ELDFG-03EH
Model Number -10-3C* -20-3C* -35-3C* -40-3C* -80-3C*
Max. Operating Pressure MPa 35
Max. Tank Line Back Pressure MPa 21
Rated Flow
@∆P = 1 MPa (4-Way Valve)*1L/min 10 20 35 40 80
Hysteresis 0.1% or less
Repeatability 0.1% or less
(0↔100％V) ms
Step Response
(Typical Rating)*2(100↔0％V) ms 16 23
(Phase: -90°) Hz
Frequency Response
(±25％Amplitude)
(Typical Rating)*2 (Gain: -3 dB) Hz
80 50
Vibration Proof G 10
Protection IP65
Ambient Temperature ºC -15 - +60
Spool Stroke to Stops mm ±2.5 ±3
Coil Resistance [20 ºC] Ω3 2
Current Consumption A 2 (Impulse Load: 3 A)
Approx. Mass kg 3.3 7.3
Electric Connection 6 + PE Connector
*1. Use the valves so that the relationship between the valve pressure difference and the flow rate, as specified in “Range
of flow control” on page 7, is met.
*2. This value is measured for each valve at a supply pressure of 14 MPa; it may differ depending on the actual circuit and
operating conditions.
ELDF G - 01 EH - 35 - 3C2P - XY - C T 10
Series
Number
Type of
Mounting
Valve
Size
Amplifier
Type
Rated Flow
L/min
(∆P= 1 MPa)
Spool Type *1Direction
of Flow
Fail-Safe
Function
Input Signal/Spool
Travel Monitoring
Design
Number
01
10: 10 L/min
20: 20 L/min
35: 35 L/min
ELDFG:
Direct
Operated
and High
Response
Type
Proportional
Electro-
Hydraulic
Directional
and Flow
Control
Valves
G:
Sub-plate
Mounting
03
EH:
OBE
Type
40: 40 L/min
80: 80 L/min
3C2: 10% Overlap
3C40:
A, B, T Connection
3C2L: 2% Overlap
(Linear Flow Gain)
XY:
Meter-In
/Meter-
Out
C: Neutral
A:
P→A, B→T
Position
B:
P→B, A→T
Position
D: Voltage Signal ± 10 V
(P→A→B→T Flow with
Positive Input)
E: Current Signal 4 - 20 mA
(P→A→B→T Flow with
12 - 20 mA Input)
F: Current Signal ± 10 mA
(P→A→B→T Flow with
Positive Input)
10

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2.2.1 Range of flow control
●Control Method: 4-Way Valve
●Control Method: 3-Way Valve
Valve Pres. Diff. [MPa] Valve Pres. Diff. [MPa]
Valve Pres. Diff. [MPa] Valve Pres. Diff. [MPa]
Flow Rate [L/min] Flow Rate [L/min]
Flow Rate [L/min] Flow Rate [L/min]

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2.3 External dimensions/valve mounting surface dimensions
ELDFG-01EH-*-*-XY-*-*-10
*1. For NULL adjustment, remove the protective screw and turn the trimmer behind the screw.
After adjustment, be sure to attach the protective screw.
*2. The 6 + PE connector is not included with the valve. Prepare it separately.
YUKEN parts number: TK290457-1
●Dimensions of Mounting Surface
Prepare the mounting surface as shown below. Basically, the dimensions of the mounting
surface conform to ISO 4401-03-02-0-94. The mounting surface should have a good
machined finish, e.g. surface roughness of 6-S.
Indicator Lamp Cylinder Port “A” Tank Port “T“ Cylinder Port “B“
Protective Screw for NULL Adjuster Hole
*1
M5 (+) Thd.
Pressure Port “P” 5.5 Dia. Throu
g
h
9.5 C’ Bore 4 Places
A
ir Vent
3 Hex. Soc.
Indicator Lamp
Color
Green
Red
Power Supply
Deviation Alarm
Cable A
pp
licable:
Outside Dia. 8 - 10 mm
6 + PE Connecto
r
*2
Name
p
late
Mounting Surface
(O-Rings Furnished)
●O-Rings for the Ports
A
S568-012 (NBR, Hs90): 4 Pieces
M5 Thd. 10 Deep
4 Places
7 Dia.
4 Places

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ELDFG-03EH-*-*-XY-*-*-10
*1. For NULL adjustment, remove the protective screw and turn the trimmer behind the screw.
After adjustment, be sure to attach the protective screw.
*2. The 6 + PE connector is not included with the valve. Prepare it separately.
YUKEN parts number: TK290457-1
*3. With standard sub-plates, one (“TA”) of the two tank ports is used, but either one may be used.
●Dimensions of Mounting Surface
Prepare the mounting surface as shown below. Basically, the dimensions of the mounting
surface conform to ISO 4401-05-04-0-94. The mounting surface should have a good
machined finish, e.g. surface roughness of 6-S.
Indicator Lamp Cylinder Port “A” Pressure Port “P“ Cylinder Port “B“
M5 (+) Thd. Tank Port “T
A
”
7 Dia. Throu
g
h
A
ir Vent
3 Hex. Soc.
Indicator Lamp
Color
Green
Red
Power Supply
Deviation Alarm
Cable A
pp
licable:
Outside Dia. 8 - 10 mm
6 + PE Connecto
r
*2
Name
p
late
Mounting Surface
(O-Rings Furnished)
●
Protective Screw for NULL Ad
j
uster Hole*1
Tank Port “TB”
4 Places
11 Dia.
4 Places
M6 Thd. 13 Deep
●O-Rings for the Ports
A
S568-014 (NBR, Hs90): 5 Pieces
11 C’ Bore 4 Places

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2.4 Fail-safe function
With reference to the information given below, select the option for the fail-safe function
according to the use of applications. A separate safety circuit should be provided if the
hydraulic actuator must be reliably held or stopped to ensure safety in the event of electric
failure (power failure, power cable disconnection, etc.) or upon startup.
- Electric System: OFF
*1. The fail-safe function’s activation time depends on the electric and hydraulic conditions.
2.5 Electrical specifications
*1. Differential input signals can be used only for the valves with the voltage signal
specifications of ±10 V (ELDFG-*EH-*-D).
*2. The recommended load resistance is 200 Ω.
Fail-Safe Function
*
1
Model Number Spool
Position Function Graphic Symbols
(F-)ELDFG-*EH-*-3C2-XY-C Neutral All Ports Blocked
(F-)ELDFG-*EH-*-3C2L-XY-C Neutral - or or
(F-)ELDFG-*EH-*-3C40-XY-C Neutral A, B, T Connection
(F-)ELDFG-01EH-*-*-XY-A ab.20% P→A→B→T Position
(F-)ELDFG-01EH-*-*-XY-B ab.20% P→B→A→T Position
(F-)ELDFG-03EH-*-*-XY-A ab.17% P→A→B→T Position
(F-)ELDFG-03EH-*-*-XY-B ab.17% P→B→A→T Position
Valve Model ELDFG-*EH-*-D ELDFG-*EH-*-E ELDFG-*EH-*-F
Pin A 24 V DC (21.6 - 26.4 V DC Included Ripple), 75 VA or more
Pin B Power Supply 0 V
Pin C Signal Common COM (0 V)
Pin D Input (+)
(Differential)*1
Pin E Input (-)
(Differential)*1
0 - ±10 V
Ri
≧
50 kΩ
4 - 20 mA
Ri = 200 Ω
0 - ±10 mA
Ri = 200 Ω
Pin F Spool Travel
Monitoring
0 - ±10 V
Ri
≧
10 kΩ
4 - 20 mA
Ri = 100 - 500 Ω*2
0 - ±10 mA
Ri = 100 - 500 Ω*2
Pin Protective Earth -
●I/O Signal Characteristics
Input Signal
Output Signal
(Spool Travel Monitoring)

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3. Valve installation
3.1 Valve mounting surface dimensions
For the valve mounting surface, see the table below.
For the detailed dimensions of the mounting surface, see 2.3 or the installation drawing.
The mounting surface should have a good machined finish, e.g. surface roughness of 6-S.
Valve Model Number Mounting Surface
ELDFG-01EH Basically, conforming to ISO 4401-03-02-0-94.
ELDFG-03EH Basically, conforming to ISO 4401-05-04-0-94.
* Use the dimensions of the valve mounting surface specified in 2.3 or the installation
drawing.
3.2 Required tools
Prepare the tools listed below.
Valve Model Number Tool Name Use
ELDFG-01EH Hexagon Wrench
(Width Across Flats: 4 mm) For M5 Valve Mounting Bolts
ELDFG-03EH Hexagon Wrench
(Width Across Flats: 5 mm) For M6 Valve Mounting Bolts
ELDFG-*EH Phillips Screwdriver for M5 Screws For Protective Screw for
NULL Adjuster Hole
3.3 Check of the valve mounting surface
(1) Any critical scratch on the valve's mounting surface may cause
fluid leakage. In particular, take extra care to ensure that there
is no critical scratch on the valve mounting surface of
equipment.
(2) Improper mounting of the O-rings may cause damage to them
or outflow of hydraulic fluid. Check that the O-rings are
properly mounted in the grooves.
3.4 Mounting position
Mount the valve with the angle of the axis line L-L' within about ±15° from the horizontal plane
as shown below.
CAUTION
CAUTION

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3.5 Installation
Upon valve installation, check the port locations with reference to the installation drawing. Be
careful to install the valve in the correct direction for the proper operation of equipment. When
mounting the valve, use four hexagon socket head cap bolts supplied with the product.
Tighten the bolts gradually and evenly in the order shown by the numbers 1 to 4 below and
repeat this cycle two to three times. Refer to the recommended tightening torque listed below.
Valve Model Number Mounting Bolt Tightening Torque
ELDFG-01EH M5 × 45L 6 - 8 Nm
ELDFG-03EH M6 × 35L 13 - 16 Nm
For valve installation, use the specified number of bolts and apply
the specified tightening torque. Failure to do so may cause
damage to the bolts or outflow of hydraulic fluid, resulting in a
major accident.
(1) Install the valve in the correct direction. Failure to do so
may interfere with the normal operation of equipment,
resulting in a major accident.
(2) Handle the valve carefully, since it is a precision device.
(3) Do not install the valve with any foreign matter left between
the valve and the mounting surface or with the O-rings
mounted improperly. Doing so may cause damage to the
O-rings or outflow of hydraulic fluid, resulting in injury or fire.
1 3
24
Tighten the bolts diagonally in the
order of 1 →2 →3 →4 →1.
Bolt Tightening
CAUTION
WARNING

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4. Wiring
To drive the valve, it must be wired to the power supply and the setting adjuster. Connect the
cable/connector to the connector port of the valve as shown below.
According to the input signal type, determine the cable length with reference to the table below.
Valve Model Number Input Signal Type Maximum Cable Length for
Input Signals
ELDFG-*EH-*- D* ±10 V 50 m*
ELDFG-*EH-*- E* 4 - 20 mA
ELDFG-*EH-*- F* ±10 mA 300 m
* If the cable length exceeds 50 m, consult us separately.
4.1 Recommended cable
Depending on the operating environment, use the following standard cable or the equivalent.
JCS 271 "Polyvinyl chloride insulated flexible cords for microphone (shielded)/MVVS"
or the equivalent
JIS C 3306 "Polyvinyl chloride insulated flexible cords (shielded)/VCTF" or the equivalent
JIS C 3401 "Control cables (shielded)/CVVS" or the equivalent
- Finished outside diameter: 8 - 10 mm
- Nominal cross-sectional area:
0.75 - 1 mm2(cable length less than 25 m) or 1 mm2(cable length of 25 m or more)
Be sure to use the recommended cable or the equivalent for
protection against noise.
Be sure to use a shielded cable, since noise generated with the
solenoid powered on may affect other equipment depending on the
wiring environment.
Cable Connection for the Valve
Cable
Connector (To Be Separately Prepared)
Connector Port of the Valve
Kee
p
the
p
owe
r
cable resistance within 1Ωand as low as
p
ossible.
CAUTION
CAUTION
CAUTION

EM-1359
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4.2 Connection between the cable and the connector
The connector is not included with the valve. Prepare a connector that conforms to the
standard specified by YUKEN and wire it correctly by following the instructions for the
connector.
Connect the connector to the power supply and the setting adjuster via the recommended
cable with reference to the connector pin assignment shown in 2.5 or the installation
drawing.
For YUKEN’s connector TK290457-1, see 4.2.1 “Assembly of the 6 + PE connector”.
4.2.1 Assembly of the 6 + PE connector
(YUKEN parts number: TK290457-1)
Components
Assembly
1. Cable preparation
a. The applicable cable outside diameter is φ8 to 10 mm.
b. The applicable lead wire size is 1.0 mm2(AWG17) or less.
c. Terminate the end of the cable as shown below.
Peel off the length of the cable sheath and the ends of the lead wires as shown above.
2. Wiring
a. Pass the cable through (6), (5), (4), (3), and (2) in this order in the direction of the arrow
in the figure above.
b. Solder the lead wires to the terminals in the terminal box (1). Then, tighten the screws
of the cable clamp (2) to hold the cable sheath securely.
c. Screw the housing (3) into the terminal box (1).
d. Put the packing (4) and the washer (5) into the housing (3). Then, tighten the cable
gland (6).
* The tightening force depends on the cable size. Tighten the cable gland so that no
gap is left between the cable and the packing.
Do not wire the connector while the power is on. Doing so may
cause electric shock, resulting in a fatal accident.
DANGER
(1) Terminal Box (2) Cable Clamp (3) Housing (4) Packing (5) Washer (6) Cable Gland

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Do not remove the amplifier cover, since the amplifier contains
precision devices. Doing so may cause malfunction or failure.
5. On-board amplifier
5.1 Appearance of the on-board amplifier
NULL Adjuster
This trimmer is used to adjust the neutral position of the
valve spool. It is set by default. If neutral position
adjustment is required for the load conditions, remove
the protective screw (M5) and turn the trimmer behind
the screw. After adjustment, be sure to attach the
protective screw. The adjustment range is about ±15%.
Indicator Lamp
●Power Supply (Green)
Lights up when the valve is powered on.
●Deviation Alarm (Red)
Lights up when the spool travel deviates about 3% or more from the input value and does not
follow the input signal for one second or more.
5.2 Wiring
NULL Adjustment Range
Input Signal
Valve Spool Travel
Rated
Travel (+)
Rated
Travel (-)
CAUTION
Connect the earth
wire independently to
the earth terminal of
the control panel.
If necessary, take
measures against AC
power noise, such as
inserting a noise filter.
Use a stabilized power supply
dedicated to the valve.
Recommended power capacity:
75 VA or more. Valve
AC Power Supply
DC Power Supply
Input Signal
Input (+)
Input (-)
Spool Travel Monitoring
COM

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♦When installing/relocating the valve or connecting the cable, be sure to turn off
the main power supply in advance. Failure to do so may cause electric shock,
fire, amplifier malfunction, or failure.
♦Be sure to use the specified power supply voltage (24 V DC). Failure to do so
ma
y
cause fire or electric shock.
♦The permissible power supply voltage fluctuation for the on-board amplifier is ±
10%. Surge voltage exceeding the permissible range may cause malfunction of
the amplifier. To prevent such cases, take measures against noise, such as
inserting a noise filter on the power supply side.
♦Do not share the AC power source to the DC power supply with high noise
generating equipment (solenoid operated directional valves, heaters, motors,
etc.).
♦If high noise generating equipment (e.g. inverter) is located in the same cabinet,
use separate power supply filters and earth wires.
5.3 Block diagram
The circuit of the on-board amplifier is shown below.
CAUTION
WARNING
Powe
r
Supply
Input
Signal
Input (+)
Input (-)
Spool Travel
Monitoring
COM
Protective Earth
Power
Indicator
Deviation
Alarm
Internal
Power
Supply
(Green)
(Red)
Low Voltage
Detection Circuit
LVDT Amplifier
The input stage for the models (F-)ELDFG-*EH-*-*-*-*-E/F (current signal) is as follo
w
.
Input Signal Input (+)
Input (-)

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5.4 Description of signals
5.4.1 Input signal and spool travel monitoring
Input signals to drive the valve are used for spool position control.
The types of input and spool travel monitoring signals differ depending on the model
number.
Model Number Input Signal Spool Travel Monitoring
ELDFG-*EH-*-D ±10 V ±10 V
ELDFG-*EH-*-E 4 - 20 mA*4 - 20 mA
ELDFG-*EH-*-F ±10 mV ±10 mV
* For the 4 - 20 mA type, an input signal of 1.5 mA or less means that the spool is in its
neutral position (12 mA).
5.5 In the event of valve malfunction
In the event of valve malfunction, check the following items.
(1) When the power indicator LED (green) does not light up:
- Check the power supply voltage.
→Check the power supply side if no voltage is present.
(2) When the deviation alarm LED (red) lights up:
- The spool has malfunctioned.
→Spool sticking or seizure caused by foreign matter in the hydraulic fluid.
(3) When the valve spool travel (monitored voltage) does not change in response to the
command input
- Check the command signal input.
→Check the input signal and valve model (input type).
- Check the wiring.
→Check that each cable has been connected correctly.
- Check the power supply voltage.
→Check the power supply side if the voltage is low.
/E＊/F＊
ELDFG-*EH-*-E/F
ELDFG-*EH-*-E/F
Ｄ
E
F
C
Valve
Input Signal
Input (+)
Input (-)
Spool Travel Monitoring
Current Output:
Current Input:

EM-1359
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6. Operating the valve
6.1 Adjustment
●The neutral position of the valve spool has been adjusted. Do not disassemble the valve to
adjust the neutral position.
●All trimmers for the on-board amplifier are set by default. If the adjustment of the neutral
position of the valve spool is required for the actual load conditions, perform NULL
adjustment as described in 5.1.
6.2 Operating environment
●Use this product for hydraulic circuit switching and speed/pressure adjustment for hydraulic
equipment.
●To ensure the stable operation of the valve and the hydraulic circuit, bleed air completely
from the hydraulic circuit.
●The valve may be used without air bleeding. If air bleeding is necessary, loosen the air vent
to release air and make sure that the solenoid is filled with the hydraulic fluid. Note that air
bleeding should be performed in unload condition.
●Take appropriate measures to protect the valve cable against noise. Using a cable longer
than the specified length may interfere with the stable performance of the valve.
●Provide a separate safety circuit, if necessary, to securely hold/stop the hydraulic actuator for
safety at the time of immediate shutdown or startup of hydraulic equipment.
●Do not operate the valve when the tank port is dry. If the tank port is dry, the inside of the
solenoid core is not filled with the hydraulic fluid, resulting in unstable valve operation and/or
solenoid failure.
●Do not connect the tank port to any line that generates a surge pressure. Doing so may
cause malfunction or failure of the valve.
●Be sure to fill the tank port “T” with the hydraulic fluid. Providing a check valve with a
cracking pressure of about 0.04 MPa is recommended to take back pressure. Do not
connect the tank pipes to other lines, but connect them directly to the reservoir.
●For environmental requirements, such as water resistance and vibration conditions, refer to
"Vibration Proof" and "Protection" in the specification table in 2.2 "Specifications".
●Meet the requirements for fluid viscosity and temperature specified in 6.3.2. Operate the
valve at an ambient temperature of 0 to 50 °C under non-condensing conditions.
●Be sure to use the valve in the operating environment (ambient temperature, etc.) specified
in this manual. Failure to do so may interfere with proper operation.
(1) The product has a structure involving internal leakage. This internal leakage
sometimes activates the actuator.
(2) The valve may generate electrical noise from its solenoid. Be aware that
such noise may affect surrounding electronic devices.
(3) The valve may become excessively heated during operation. Avoid
touching the valve (solenoid, in particular) during operation or immediately
after the end of operation. Failure to do so may result in burn.
(4) When operating the product manually, ensure safety by taking precautionary
measures, e.g. keeping people away from the moving parts of equipment.
CAUTION

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6.3 Hydraulic fluid
6.3.1 Fluid type
Petroleum base oil: Use a fluid equivalent to ISO VG32 or 46.
Synthetic fluid: Use a phosphate ester or polyol ester fluid.
When phosphate ester fluids are used, prefix “F-” to the model number
because the special seals (fluororubber) are required to be used.
(Note) For use with hydraulic fluids other than those listed above, consult us
separately.
6.3.2 Fluid viscosity and temperature
Meet the following requirements for fluid viscosity and temperature during operation.
- Viscosity: 15 to 400 mm2/s
- Fluid temperature: - 15 to 60 ºC
Note that the recommended fluid temperature ranges from 40 to 50 ºC.
6.3.3 Control of contamination
Contamination of hydraulic fluid with foreign matter often affects the proper operation of
the valve. Keep hydraulic fluid clean and use a line filter. To ensure a longer service
life of the valve, improving hydraulic fluid cleanliness is recommended.
Contamination Level
NAS 1638 Class 10
ISO 4406 21/19/15
Never use contaminated fluid.
Doing so may result in malfunction or failure of the valve.
7. Maintenance
●The service life of the O-rings is about two or three years depending on the condition of
valve operation. Please keep spare O-rings handy for replacement in the event of fluid
leakage.
●The components and performance of the valve deteriorate as the duration of service
increases or depending on the operating conditions. To keep the valve in working order
and prevent unexpected failure of hydraulic equipment, inspecting the valve regularly is
recommended. The recommended inspection interval is at least two to three years. The
valve deterioration conditions depend on the operating conditions of hydraulic equipment
and the fluid contamination level. Thus, performing regular inspection depending on the
situation is recommended. For periodic maintenance, contact our customer support.
●Contamination of hydraulic fluid with foreign matter often affects the proper operation of the
valve. It may cause failure or shorten the valve’s service life. Keep hydraulic fluid clean
(contamination level: NAS class 10/ISO 4406 21/19/15 or better). Also, use a line filter and
inspect/clean it regularly.
●Petroleum base oil containing water shortens the valve’s service life. To avoid this situation,
inspect the fluid regularly.
●Air entry into the circuit may impair the proper operation of the valve. Bleed air completely
from the circuit.
CAUTION