Hyundai HX145LCR Manual page 316

2. BOOM PRIORITY EPPR VALVE 2. BOOM PRIORITY EPPR VALVE
1) 1) COMPOSITION COMPOSITION
The boom priority EPPR valve is built in a manifold and mainly consisting of valve body and coil.
This EPPR valve installed under the solenoid valve.
2) 2) CONTROL CONTROL
The boom priority EPPR valve has to be controlled by a specific electronic amplifier card, which is
supplying the coil with a current 580 mA at 30
OPERATING PRINCIPLE OPERATING PRINCIPLE
3) 3)
(1) (1) Structure Structure
A
P
T
1 O-ring
2 Support ring
(2) (2) Operation Operation
In de-energized mode the inlet port (P) is closed and the outlet port (A) is connected to tank port
(T).
In energized mode the solenoid armature presses onto the control spool with a force
corresponding to the amount of current. This will set a reduced pressure at port A. The setting is
proportional to the amount of current applied.
(3) (3) Maximum pressure relief Maximum pressure relief
If a pressure from outside is applied on port A the valve may directly switch to tank port (T) and
protect the system before overload.
1 5
P T
2 Control spool 3
P : Pilot supply line
A
T : Return to tank
A : Secondary pressure to flow MCV
3 Valve body
4 Coil
Ω
and 24 V.
4
5-57
6
5 Connector
6 Cover cap
21095MS14