Komatsu Galeo PC138US-8 Shop Manual page 199

10 Structure, function and maintenance standard
Function
The EPC valve consists of the proportional
q
solenoid portion and the hydraulic valve por-
tion.
When it receives signal current (i) from the
q
pump controller, it generates the EPC output
pressure in proportion to the size of the signal,
and outputs it to the control valve.
PC138US, USLC-8
Operation
1) When signal current is 0
(coil is de-energized)
When there is no signal current flowing from
q
the controller to coil (14), coil (14) is de-ener-
gized.
Spool (11) is pushed to the right by spring (12).
q
Port (P) closes and the pressurized oil from the
q
front pump does not flow to the control valve.
The pressurized oil from the control valve is
q
drained to the tank via port (C) and port (T).
SEN02550-01
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