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 supply and the three-pin command input device
ACTION
Check Power Input. Disconnect the two-pin power
supply connector from 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
command input device connector from EP Control
electronic module. Inspect the two connectors for
corrosion, loose contacts, loose wires and broken wires.
If 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.
If ±100 mA differential 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 ±2.8 volts
for input command currents of ±100 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. Reverse Steps 11 and 12 on pages 11
and 12. 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 19 for typical readings.
Check Electronic Module. Disconnect the two-pin power
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. Reverse Steps 11 and 12 on pages 11
and 12. 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 19 for typical readings.
EATON CORPORATION Fluid Power
EP Control for Medium Duty 72400 Piston Pumps
Installation 04-10-0003-EN-0901 September 2001 15