Komatsu ecot3 PC300LC-8 Shop Manual page 123

10 Structure, function and maintenance standard
Function
q The EPC valve consists of the proportional
solenoid portion and the hydraulic valve por-
tion.
When it receives signal current (i) from the
q
controller, it generates the EPC output pres-
sure in proportion to the size of the signal, and
outputs it to the LS (PC) valve.
PC300, 350-8
Operation
1) When signal current is 0 (coil is deener-
gized)
When there is no signal current flowing from
q
the controller to coil (2), coil (2) is deenergized.
q Spool (5) is pushed to the left by spring (4).
q Port (P) closes and the pressurized oil from the
self pressure reducing valve does not flow to
the LS (PC) valve.
q The pressurized oil from the LS (PC) valve is
drained to the tank via port (C) and port (T).
SEN01993-00
27