Komatsu Galeo PC800-8 Shop Manual page 143

10 Structure, function and maintenance standard
Function
• The EPC valve consists of the proportional sole-
noid portion and the hydraulic valve portion.
• When it receives signal current (i) from the con-
troller, it generates the EPC output pressure in
proportion to the size of the signal, and outputs it
to the VC valve.
Operation
1. When signal current is 0 (coil is de-
energized)
• When there is no signal current flowing from the
controller to coil (5), coil (5) is de-energized.
• Spool (2) is pushed to the right by spring (3).
• Port (P) closes the pressurized oil from the self
pressure reducing valve does not flow to the con-
trol valve.
• The pressurized oil from the VC valve is drained
to the tank through port (C) and port (T).
PC800, 850-8
SEN00383-03
21