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
