Troubleshooting - Eaton EP Control Manual

Troubleshooting

SYMPTOM CAUSE
No Flow in Either Defective Power
Direction Connection, or
Loose Wires
Command Signal
Missing
Defective
Solenoid Coil
Defective
Electronic Module
Manual Override
Does Not Function
Flow Only in One Command Signal
Direction Incorrect
14 EATON EP Control for Medium Duty 72400 Piston Pumps Parts & Service 08-10-0003-EN-0901 September 2001
ACTION
Check Power Input. Disconnect the two-pin connector from the power supply to the
EP Control electronic module. Inspect the two connectors for corrosion, loose wires or
broken wires. Measure the DC voltage across pins "A" and "B" at the connector. The
reading should be between 9 to 30 Vdc.
Check Command Input Signal. Disconnect the three-pin connector from the command
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.
Check Solenoid Coil. Disconnect the two-pin power supply and the 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 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.
Check Electronic Module. Disconnect the two-pin power supply and the 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 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.
Check Manual Override. Disconnect two-pin power supply and the 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 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.
Check Command Input Signal. Disconnect the three-pin command input device
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.