Eaton EP Control User manual

Electronic Proportional (EP) Control for
Medium Duty 72400 Piston Pumps
Parts & Service 08-10-0003
EN-0901

2EATON EP Control for Medium Duty 72400 Piston Pumps Parts & Service 08-10-0003-EN-0901 September 2001
EP Control for
Medium Duty
72400 Piston
Pumps
Table of Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Parts and Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Tools Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Reassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Neutral Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Interconnect Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Troubleshooting Reference Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

3EATON EP Control for Medium Duty 72400 Piston Pumps Parts & Service 08-10-0003-EN-0901 September 2001
In order to assure the most
reliable installation and
operation of any electronic
control, proper component
selection and installation
procedures must be followed
with respect to interconnec-
tion wiring harnesses, input
command signal devices,
fusing, and input power
switching.
Appropriate industry practices
must be followed to prevent
damage of and shorting of all
electrical and electronic
components caused by
environmental hazards and
application specific hazards.
Typical hazards that damage
the wiring harnesses or other
components are abrasion,
moving objects, and heat from
the engine or exhaust system.
Moisture can damage poorly
sealed connectors and/or
components, causing short
circuits and other problems
like corrosion.
A switch must be installed
in line with (+ battery) power
to the electronic module, so
that power may quickly be
disconnected in case of
emergency (component failure
or inadvertent commands).
A fuse rated at the maximum
module operating current (3
Amp) must be installed in the
+ battery line to the electronic
module.
All the electrical connections
to the EP Control electronic
module must be disconnected
prior to performing any
electrical welding on the
vehicle or machine. The elec-
tronic module and/or the
hydraulic pump are not to be
used as a connection point for
electrical welding equipment.
During initial start-up and/or
checkout of the machine after
service, the machine must be
placed on jack stands to pre-
vent inadvertent movement.
The reliable operation and
suitability of this product is
dependent upon how it is
applied and the other
components used in the
system. The system integrator
must review all aspects of the
application
and all of the components
used to assure proper
operation and reliability.
This manual provides the
necessary information to
troubleshoot and repair the
EP Control for Eaton®Medium
Duty 72400 piston pumps.
The EP Control consists of two
main parts, the valve assembly
and the electronic module.
Note: Many EP Control
components are not repairable,
i.e., the EP Control electronic
module has internal circuitry that
is environmentally encapsulated
into its housing. Replacing the
electronic module with a new
one is necessary if the module
is the source of a fault.
Complete kits are listed along
with individual components
should you choose to replace
individual components.
CAUTION
Information contained in this parts and service manual is
accurate as of the publication date and is subject to change
without notice. Performance values are typical values.
Customers are responsible for selecting products for their
applications using normal engineering methods.

4EATON EP Control for Medium Duty 72400 Piston Pumps Parts & Service 08-10-0003-EN-0901 September 2001
Parts List
ITEM PART NO. QTY. DESCRIPTION
1111520-016 1 Electronic Module - 1-6 V Input - 12/24 V
1111520-020 1 Electronic Module - ±4-20 mA Input - 12/24 V
2101673-175 4 10-24 Button Head Cap Screw (1/8" hex key) - 1.75"
316045-203 4 #10 Lockwasher
416147-326 6 10-24 Hex Head Cap Screw (5/32” hex key) - 2.75"
5111501-000 2 Solenoid Tube Subassembly*
6114241-012 1 Solenoid Coil Subassembly - 12 V (includes two coils and wiring harness)
6114241-024 1 Solenoid Coil Subassembly - 24 V (includes two coils and wiring harness)
74993057-012 1 Valve Assembly - (includes items 5 & 6 - 12 V Solenoid Coil & Tube Subassemblies)
74993057-024 1 Valve Assembly - (includes items 5 & 6 - 24 V Solenoid Coil & Tube Subassemblies)
872400-752 2 Electronic Module Bracket
916147-312 4 10-24 Hex Head Cap Screw (5/32" hex key) - 1.25" (can use existing from pump)
10 72400-631 1 Control Valve Gasket
*Includes necessary O-Rings.
EP Control Kits
MODEL CODE INPUT VALVE ELECTRONIC
KIT NO. REFERENCE KIT DESCRIPTION SIGNAL ASSEMBLY MODULE VOLTAGE
9900015-000 EE EP Ctrl Kit MD 72400: 1-6 V input, w/o brackets 1-6 V 4993057-012 111520-016 12/24 V
9900016-000 EC EP Ctrl Kit MD 72400: 12 V coils w/o electronics — 4993057-012 — 12 V
9900017-000 ED EP Ctrl Kit MD 72400: 24 V coils w/o electronics — 4993057-024 — 24 V
9900019-000 EG EP Ctrl Kit MD 72400: ±4-20 mA input, w/o brackets ±4-20 mA 4993057-012 111520-020 12/24 V
9900021-000 EG EP Ctrl Kit MD 72400: ±4-20 mA input ±4-20 mA 4993057-012 111520-020 12/24 V
9900022-000 EE EP Ctrl Kit MD 72400: 1-6 V input 1-6 V 4993057-012 111520-016 12/24 V
990830-000 EP Ctrl Electronic Module 1-6 V 1-6 V — 111520-016 —
990832-000 EP Ctrl Electronic Module ±4-20 mA ±4-20 mA — 111520-020 —
72400-942 Brackets and Screws
Note: All kits using Eaton EP Control Electronic Modules use 12 V coils.
Parts
Electronic Module Mating Connector Kit
KIT NO. PART (QTY.) DELPHI PACKARD P/N
990762-000 Command Input Signal Connector (1) 1211 0293
Terminal (3) 1204 8074
Cable Seal (3) 1204 8086
Cavity Plug (1) 1205 9168
Secondary Lock (1) 1205 2845
Power Supply Connector (1) 1205 2641
Terminal (2) 1204 8074
Cable Seal (2) 1204 8086
Secondary Lock (1) 1205 2634
Recommended wire size: 16 - 18 AWG
Recommended cable diameter: 2.03 - 2.80 mm
Alternate reference source: Pioneer Standard Electronics 1-800-257-6613
www.pios.com
Solenoid Coil Mating Connector Kit
(not needed when using an Eaton Electronic Module)
KIT NO. PART (QTY.) DELPHI PACKARD P/N
9900023-000 Connector (1) 1218 6568
Terminal (4) 1204 8074
Cable Seal (4) 1204 8086
Secondary Lock (1) 1204 7948
Recommended wire size: 16 - 18 AWG
Recommended cable diameter: 2.03 - 2.80 mm
Alternate reference source: Pioneer Standard Electronics 1-800-257-6613
www.pios.com
Solenoid Connector Update Kit
KIT NO. PART (QTY.) DELPHI PACKARD P/N
9900045-000 Tool (1) 1209 4429
4-Pin Housing Connector (Female) (1) 1218 6568
4-Pin Housing Connector (Male) (1) 1218 6271
EP Control Connector Kits

5EATON EP Control for Medium Duty 72400 Piston Pumps Parts & Service 08-10-0003-EN-0901 September 2001
Parts
•1/8" Bit Socket or Hex Key
•5/32" Bit Socket or Hex Key
•9/16" Open-End Wrench
•3/4" Open-End Wrench
•Flat Blade Screwdriver
•12 VDC Power Supply or Battery
•Voltage Ohm Meter (VOM)
•Charge Pressure Gauge
Required Tools for Disassembly, Repair and Test

6EATON EP Control for Medium Duty 72400 Piston Pumps Parts & Service 08-10-0003-EN-0901 September 2001
Disassembly
Step 2
Using a 5/32" hex wrench (or bit
socket), remove the two cap
screws on each side of the pump
holding the “L” brackets to the
pump.
Step 3
Using a 1/8" hex key (or bit socket),
remove the four 10-24 button head
cap screws and lockwashers on top
of the electronic control.
Disconnect the four-pin connector
between the EP Control module
and the solenoids. Caution must be
used when disconnecting these
connectors as they are latched with
keepers.
Step 1
Disconnect all power to the input
device. Carefully disconnect the
command input device from the
three-pin connector on the EP
Control electronics module by
releasing the connector latches.
Thoroughly clean the outside of the
EP Control and surrounding pump
surface.
To Pump
Repair & Service

7EATON EP Control for Medium Duty 72400 Piston Pumps Parts & Service 08-10-0003-EN-0901 September 2001
Step 5
Using a 3/4" open-end wrench,
remove each tube subassembly by
turning counterclockwise.
If only replacing the coil and tube
subassemblies, skip to Reassembly,
Step 12.
Step 6
Using a 5/32" hex key (or bit
socket), remove the six 10-24 hex
head cap screws.
Carefully lift the EP Control valve
assembly upward and slide the
assembly away from the pump to
disengage the feedback link from
the servo piston. Note which slot
the feedback link is assembled into.
Step 4
The two solenoid coils can be
removed by turning each solenoid
tube knob counterclockwise.
Remove the knob and associated
O-ring. Slide the coil off the tube
subassembly. Repeat for other coil.
Note: Each coil is stamped with a
position number “1” and “2” and
the voltage “12V” or “24V”. There
are also numbers stamped on the
valve assembly indicating positions
#1 and #2. When reassembling the
coils, the numbers stamped on the
coil and valve assembly must
match. Refer to page 3.
Repair & Service

8EATON EP Control for Medium Duty 72400 Piston Pumps Parts & Service 08-10-0003-EN-0901 September 2001
Step 7
Remove and discard the control
valve gasket.
Step 8
In most cases it will not be
necessary to remove the control
orifices that are staked in the pump
housing. Only remove if the orifice
size needs to be changed. The
orifice size is stamped on the flat
plate orifices in the pressure,
servo-1, and servo-2 ports.
S2 S1
P
Reassembly Step 9
Clean the EP Control mounting
surface. Install a new control valve
gasket by aligning with screw and
porting holes.
Repair & Service

9EATON EP Control for Medium Duty 72400 Piston Pumps Parts & Service 08-10-0003-EN-0901 September 2001
Step 10
Carefully install the EP Control valve
assembly on the pump housing,
making sure the feedback link is
installed in the appropriate servo
piston land.
Note: There is a narrow land on the
servo piston for the EP Control
feedback link and a wide land for
the swashplate follower.
Replace and hand tighten the six
10-24 hex head cap screws.
Step 11
Locate the new solenoid tube
subassembly. Each solenoid tube
subassembly comes with new
O-rings installed on the tubes.
The tube subassemblies are
interchangeable.
Step 12
Using a 3/4" open-end wrench,
replace each tube subassembly by
turning clockwise. Torque the
solenoid tubes to 32.5 ±2.5 lbf·ft.
Repeat for other tube subassembly.
Replace the coils. Note: The
position number stamped on the
coil and the valve assembly must
match.
Repair & Service

10 EATON EP Control for Medium Duty 72400 Piston Pumps Parts & Service 08-10-0003-EN-0901 September 2001
Step 13
Attach the retaining knob, and
torque to 12±1 lbf·ft.
Step 14
Using a 5/32" hex key or bit socket,
tighten the six 10-24 hex head cap
screws. Torque to 60-68 lbf·ft.
Step 15
Neutral Adjustment
Caution: All hoses and fittings
must be connected, and the pump
ready for operation before
attempting to check neutral
adjustment. Electrical wiring
harnesses for the solenoid coils
and command input should be left
disconnected while adjusting
neutral.
A. Disengage the input drive to
vehicle or elevate wheels.
B. Install charge pressure gauge. A
0-1000 psi or 0-1500 psi pressure
gauge is recommended.
C. Start the prime mover.
D. Loosen the locknut holding the
neutral adjustment screw until it
is just snug enough that the
threaded screw can be rotated.
Use a 9/16" end wrench to hold
the locking nut while rotating the
neutral adjustment screw.
Repair & Service

11EATON EP Control for Medium Duty 72400 Piston Pumps Parts & Service 08-10-0003-EN-0901 September 2001
Install and
Torque
Alignment slot to be
towards control spool ±90˚
Spool
Solenoid Solenoid
E. Note the number stamped on
the cap of the low pressure relief
valve. -022 is 220 psig (15 bar), -
030 is 305 psig (21 bar), etc. This
will be the high setting. Settings
can vary from 155 psig (11 bar) to
325 psig (22.4 bar).
F. Slowly rotate the neutral adjust-
ment screw clockwise until
charge pressure drops to its low
setting. Mark the neutral adjust-
ment screw location.
Note: The charge pressure low
setting is usually 40-60 psig
lower than the high setting.
G. Rotate the neutral adjustment
screw counterclockwise. The
charge pressure will rise.
Continue turning counterclock-
wise until the pressure drops
again to its low setting. Mark
the neutral adjustment screw
location.
H. Rotate the neutral adjustment
screw to the position between
the two marks.
I. Carefully hold adjustment screw
while torquing locknut. Torque
locknut to 10±1 lbf·ft. Neutral
adjustment is completed.
Step 16
Install the two “L” brackets on each
end of the servo piston cap with
the flat end facing up to hold the
electronic module. Replace the 10-
24 cap screws on the pump and
torque with 5/32" hex key or bit
socket to 60-68 lbf·in.
300
200 400
100 500
0600
PSI
300
200 400
100 500
0600
PSI
High
Setting Range
Low
Setting Range
Repair & Service

12 EATON EP Control for Medium Duty 72400 Piston Pumps Parts & Service 08-10-0003-EN-0901 September 2001
Step 18
Carefully position the EP Control
electronic module. Tuck all cables
under the module. Caution: Avoid
pinching cables at mounting points.
Step 19
Install the four lockwashers and
four 10-24 button head cap screws.
Place two of the screws through
the “L” brackets. Using a 1/8” hex
key or bit socket, torque the four
screws to 60-68 lbf·in.
Step 17
Connect the four-pin connectors
between the EP Control electronic
module and the solenoid coils. The
connectors must be latched
securely.
Step 20
Power should still be disconnected
to the input device. Connect the
command input device to the three-
pin connector on the EP Control
electronic module.
Step 21
Connect the electrical power
source to the two-pin connector on
the EP Control electronic module.
Install a 3 Amp SLO-BLO®fuse per
the Interconnect Schematic on
page 12. Recheck your work and
then reconnect the power to the
vehicle or system.
Step 22
The pump is now ready to return to
operation.
Repair & Service

13EATON EP Control for Medium Duty 72400 Piston Pumps Parts & Service 08-10-0003-EN-0901 September 2001
Interconnect
Schematic
A +
B -
POWER
SUPPLY
CONNECTOR
(2-Pin)
see chart
Customer
Supplied
Components Valve
Assembly
Electronic
Module Proportional
Solenoid 1
Solenoid
Connector
Proportional
Solenoid 2
S1
S2
P
Mechanical
Swashplate
Feedback
Supply Orifice
(Optional)
Servo Orifices
(Optional)
A
B
C
COMMAND
INPUT SIGNAL
CONNECTOR
(3-Pin)
see chart
Battery or
Power Supply
FUSE
On/Off Switch
+-
A
B
C
D
Power Supply Connector
PINS WIRE COLOR SIGNAL
ARed + Supply Voltage
BBlack Supply Return
Fuse Rating
3 Amp SLO-BLO®(Time Delay) fuse for
12-24 Vdc system - customer supplied
Command Input Signal Connector
COMMAND INPUT SIGNAL PINS WIRE COLOR SIGNAL
ABlack Ref Low - 1 Vdc
1 to 6 Vdc Potentiometric B Green Command (wiper)
CRed Ref Hi - 6 Vdc
AOrange Loop Return
4 to 20 mA Current Loop B White Loop In
CNo Connection Required*
*EP Control Electronic Module Mating Connector Kit 990762-000 contains plug
used to seal mating end connector.
Pump Displacement
vs. Input Signal
Typical Control Characteristics
Full Stroke Port B Flow*
Full Stroke Port A Flow*
Minimum Neutral Range
A
BC D E
*Note: Actual flow direction depends
on pump type and rotation
ABCDE
(MAX) (MIN) (MIN) (MAX)
Command Input Signal
1-6 Vdc 1.5 Vdc 3.3 Vdc 3.5 Vdc 3.7 Vdc 5.5 Vdc
±4-20 mA -20 mA -4.5 mA 0 mA +4.5 mA +20 mA
Shaft Rotation
CCW Solenoid #2 Neither Solenoid #1
Flow OUT port “B” No flow Flow OUT port “A”
CW Solenoid #2 Neither Solenoid #1
Flow OUT port “A” No Flow Flow OUT port “B”
Note: The +20 mA command input signal configuration
operates the pump in one direction. The customer has to
change the polarity on the -20 mA signal to operate the
pump in the opposite direction.

14 EATON EP Control for Medium Duty 72400 Piston Pumps Parts & Service 08-10-0003-EN-0901 September 2001
No Flow in Either Defective Power Check Power Input. Disconnect the two-pin connector from the power supply to the
Direction Connection, or EP Control electronic module. Inspect the two connectors for corrosion, loose wires or
Loose Wires broken wires. Measure the DC voltage across pins “A” and “B” at the connector. The
reading should be between 9 to 30 Vdc.
Command Signal Check Command Input Signal. Disconnect the three-pin connector from the command
Missing input device to the EP Control electronic module. Inspect the two connectors for
corrosion, loose contacts, loose wires and broken wires.
If 1-6 Vdc joystick or potentiometer is used, measure the DC voltage across pins “A” and
“B” at the connector. Move the joystick or potentiometer position. The voltage reading
will be approximately 2.5 volts DC at joystick neutral or the half range position of the
potentiometer. The DC voltage will be approximately 5 volts at one end of the joystick or
potentiometer travel. At the opposite end of travel the DC voltage will be approximately
zero.
If ±4-20 mA current loop input is used, measure the DC voltage across pins “A” and “B”
at the connector. The DC voltage reading should be approximately zero at zero input cur-
rent which occurs at command input neutral. The DC voltage reading should be approxi-
mately ±5 volts for input command currents of ±20 mA respectively.
Defective Check Solenoid Coil. Disconnect the two-pin power supply and the three-pin command
Solenoid Coil input device connectors from the EP Control electronic module. Inspect the connectors
for corrosion, loose contacts, loose wires and broken wires. Remove the EP Control
electronic module. Refer to instructions on page 5. Disconnect the two mating four-pin
connectors. Measure the coil resistance across the designated pins at the solenoid
four-pin connector. Refer to the Solenoid 4-pin Connector chart on page 17 for typical
readings.
Defective Check Electronic Module. Disconnect the two-pin power supply and the three-pin
Electronic Module command input device connectors from the EP Control electronic module. Inspect the
connectors for corrosion, loose contacts, loose wires and broken wires. Remove the EP
Control electronic module. Refer to instructions on page 5. Caution: The engine or
motor driving the pump should not be running. Connect command input device and
power to the module. Measure the current to the coil at the four-pin connector. Activate
the input device end to end and at neutral. Monitor the current on one coil, and then on
the other. Refer to Command Input Device chart on page 17 for typical readings.
Manual Override Check Manual Override. Disconnect two-pin power supply and the three-pin command
Does Not Function input device connectors from the EP Control electronic module. Inspect the connectors
for corrosion loose contacts, loose wires and broken wires. Remove the valve assembly.
Refer to instructions on page 6. Use a small Phillips screwdriver to push on the manual
override of the solenoid tube’s solenoid tube actuator pin.
Flow Only in One Command Signal Check Command Input Signal. Disconnect the three-pin command input device
Direction Incorrect connector from the EP Control electronic module. Inspect the two connectors for
corrosion, loose contacts, loose wires and broken wires.
If 1-6 Vdc joystick or potentiometer is used, measure the DC voltage across pins “A” and
“B” at the connector. Move the joystick or potentiometer position. The voltage reading
will be approximately 2.5 volts DC at joystick neutral or the half range position of the
potentiometer. The DC voltage will be approximately 5 volts at one end of the joystick or
potentiometer travel. At the opposite end of travel the DC voltage will be approximately
zero.
If ±4-20 mA current loop input is used, measure the DC voltage across pins “A” and
“B” at the connector. The DC voltage reading should be approximately zero at zero input
current which occurs at command input neutral. The DC voltage reading should be
approximately ±5 volts for input command currents of ±20 mA respectively.
SYMPTOM CAUSE ACTION
Troubleshooting

15EATON EP Control for Medium Duty 72400 Piston Pumps Parts & Service 08-10-0003-EN-0901 September 2001
Flow Only in One Defective Check Solenoid Coil. Disconnect the two-pin power supply and the three-pin command
Direction (con’t) Solenoid Coil input device connectors from the EP Control electronic module. Inspect the connectors
for corrosion, loose contacts, loose wires and broken wires. Remove the EP Control
electronic module. Refer to instructions on page 5. Disconnect the two mating four-pin
connectors. Measure the coil resistance across the designated pins at the solenoid
four-pin connector. Refer to the Solenoid 4-pin Connector chart on page 17 for typical
readings.
Defective Solenoid Check Solenoid Tube Subassembly. Disconnect the two-pin power supply and the
Tube Subassembly three-pin command input device connectors from the EP Control electronic module.
Inspect the connectors for corrosion, loose contacts, loose wires and broken wires.
Remove the two solenoid tube subassemblies. Visually inspect the actuator pin in the
tube subassembly. The pin should be free to move.
Defective Check Electronic Module. Disconnect the two-pin power supply and the three-pin
Electronic Module command input device connectors from the EP Control electronic module. Inspect the
connectors for corrosion, loose contacts, loose wires and broken wires. Remove the EP
Control electronic module. Refer to instructions on page 5. Caution: The engine or
motor driving the pump should not be running. Connect command input device and
power supply to the electronic module. Measure the current to the coil at the four-pin
connector. Activate the input device end to end and at neutral. Monitor the current on
one coil, and then on the other. Refer to Command Input Device chart on page 17 for
typical readings.
Flow in Neutral Command Signal Check Command Input Signal. Disconnect the three-pin command input device
Incorrect connector from the EP Control electronic module. Inspect the two connectors for
corrosion, loose contacts, loose wires and broken wires.
If 1-6 Vdc joystick or potentiometer is used, measure the DC voltage across pins “A” and
“B” at the connector. Move the joystick or potentiometer position. The voltage reading
will be approximately 2.5 volts DC at joystick neutral or the half range position of the
potentiometer. The DC voltage will be approximately 5 volts at one end of the joystick or
potentiometer travel. At the opposite end of travel the DC voltage will be approximately
zero.
If ±4-20 mA current loop input is used, measure the DC voltage across pins “A” and “B”
at the connector. The DC voltage reading should be approximately zero at zero input cur-
rent which occurs at command input neutral. The DC voltage reading should be approxi-
mately ±5 volts for input command currents of ±20 mA respectively.
Neutral Out of Check Neutral Adjustment. Disconnect the two-pin power supply and the three-pin
Adjustment command input device connectors from the EP Control electronic module. Inspect the
connectors for corrosion, loose contacts, loose wires and broken wires. Remove the EP
Control electronic module. Refer to instructions on page 5. Disconnect the two four-pin
solenoid connectors. Follow instructions for setting neutral on page 9 Step 15.
Flow Limited, Command Signal Check Command Input Signal. Disconnect the three-pin command input device
Cannot Achieve Incorrect connector from the EP Control electronic module. Inspect the two connectors for
Full Pump Stroke corrosion, loose contacts, loose wires and broken wires.
If 1-6 Vdc joystick or potentiometer is used, measure the DC voltage across pins “A” and
“B” at the connector. Move the joystick or potentiometer position. The voltage reading
will be approximately 2.5 volts DC at joystick neutral or the half range position of the
potentiometer. The DC voltage will be approximately 5 volts at one end of the joystick or
potentiometer travel. At the opposite end of travel the DC voltage will be approximately
zero.
If ±4-20 mA current loop input is used, measure the DC voltage across pins “A” and “B”
at the connector. The DC voltage reading should be approximately zero at zero input cur-
rent which occurs at command input neutral. The DC voltage reading should be approxi-
mately ±5 volts for input command currents of ±20 mA respectively.
SYMPTOM: CAUSE: ACTION:
Troubleshooting

16 EATON EP Control for Medium Duty 72400 Piston Pumps Parts & Service 08-10-0003-EN-0901 September 2001
Flow Limited, Defective Check Electronic Module. Disconnect the two-pin power supply and the three-pin
Cannot Achieve Electronic Module command input device connectors from the EP Control electronic module. Inspect the
Full Pump Stroke connectors for corrosion, loose contacts, loose wires and broken wires. Remove the EP
(con’t) Control electronic module. Refer to instructions on page 5. Caution: The engine or
motor driving the pump should not be running. Connect command input device and
power supply to the electronic module. Measure the current to the coil at the four-pin
connector. Activate the input device end to end and at neutral. Monitor the current on
one coil, and then on the other. Refer to Command Input Device chart on page 17 for
typical readings.
Manual Override Check Manual Override. Disconnect the two-pin power supply and the three-pin
Does Not Function command input device connectors from the EP Control electronic module. Inspect the
connectors for corrosion loose contacts, loose wires and broken wires. Remove the
valve assembly. Refer to instructions on page 6. Use a small Phillips screwdriver to
push on the manual override of the solenoid tube’s actuator pin should move the spool.
Does Not Return Command Signal Check Command Input Signal. Disconnect the three-pin command input device
to Neutral Incorrect connector from the EP Control electronic module. Inspect the two connectors for
corrosion, loose contacts, loose wires and broken wires.
If 1-6 Vdc joystick or potentiometer is used, measure the DC voltage across pins “A” and
“B” at the connector. Move the joystick or potentiometer position. The voltage reading
will be approximately 2.5 volts DC at joystick neutral or the half range position of the
potentiometer. The DC voltage will be approximately 5 volts at one end of the joystick or
potentiometer travel. At the opposite end of travel the DC voltage will be approximately
zero.
If ±4-20 mA current loop input is used, measure the DC voltage across pins “A” and “B”
at the connector. The DC voltage reading should be approximately zero at zero input cur-
rent which occurs at command input neutral. The DC voltage reading should be approxi-
mately ±5 volts for input command currents of ±20 mA respectively.
Neutral Out of Check Neutral Adjustment. Disconnect the two-pin power supply and the three-pin
Adjustment connectors from the EP Control electronic module. Inspect the connectors for
corrosion, loose contacts, loose wires and broken wires. Remove the EP Control
electronic module. Refer to instructions on page 5. Disconnect the two solenoid
four-pin connectors. Follow instructions for setting neutral on page 9 Step 15.
SYMPTOM: CAUSE: ACTION:
Troubleshooting

17EATON EP Control for Medium Duty 72400 Piston Pumps Parts & Service 08-10-0003-EN-0901 September 2001
Troubleshooting
Reference Settings
Solenoid 4-Pin Connector
PINS SOLENOID 12 VOLT COIL 24 VOLT COIL
A & B Coil 1 5 ohms 21 ohms
C&D Coil 2 5 ohms 21 ohms
Note: Only 12 volt coils are used with EP Control electronics module
Joystick Position
DC VOLTAGE MEASURED ACROSS DESIGNATED
PINS AT THE CUSTOMER THREE-PIN CONNECTOR
Ato B
Full-Forward 5 Vdc
Neutral 2.5 Vdc
Full-Reverse 0 Vdc
Command Input Device – 12/24 Volt Systems (5 Ωcoils)
CURRENT TO COIL 1 CURRENT TO COIL 2
PINS A & B PINS C & D
YELLOW & WHITE WIRES ORANGE & BLACK WIRES
Max command in Minimum 1.5 A 0 A
one direction Maximum 2.0 A 0 A
Neutral 0 A 0 A
Max command in 0 A Minimum 1.5 A
the same direction 0 A Maximum 2.0 A
Troubleshooting

© 2001 Eaton Corporation
All Rights Reserved
Printed in USA
Form No. 08-10-0003
EN-0901
September 2001
ISO-9001 CERTIFICATED FIRM
DET NORSKE VERITAS INDUSTRY BV, THE NETHERLANDS
ACCREDITED BY
THE DUTCH COUNCIL
FOR CERTIFICATION
Reg. No. 24
Quality System Certified
Products in this publication are manufactured
in an ISO-9001-certified site.
Eaton
14615 Lone Oak Road
Eden Prairie, MN 55344
Telephone: [phone]
Fax: [phone]
www.eaton.com
Eaton
46 New Lane, Havant
Hampshire PO9 2NB
England
Telephone: [phone]
Fax: [phone]
www.eaton.com