H1, H2, K1, K2 Controls; Operation; Functional Description; Solenoid Valve - Danfoss 51 Series Service Manual

Service Manual

H1, H2, K1, K2 Controls

Operation

Repair

Series 51 Hydraulic Proportional Controls Service Manual

Functional Description

The H1, H2, K1, and K2 controls consist of a ported housing mounted on the multiblock. It contains a
solenoid valve and internal porting to direct the external variable signal pressure through the solenoid
valve to the end of the 4-way valve. A threshold spring and ramp spring(s) act on the opposite end of the
4-way valve.

Solenoid Valve

The solenoid valve (M1) is a 2-position 3-way valve that passes the external signal pressure to the end of
the 4-way valve, or blocks the external signal and drains the end of the 4-way valve to the motor case.
The H1 and K1 solenoid valves have a 12-volt coil with DIN connector. The H2 and K2 solenoid valves
have a 24-volt coil with DIN connector. The 4-way valve and the solenoid valve are the same for H1, H2,
K1, and K2 controls. The control housings are different between the H1, H2, and the K1, K2 controls. The
logic for the control is:
•
If H1 or H2 are energized operation is proportional; if de-energized output is maximum displacement.
•
If K1 or K2 are energized, output is maximum displacement; if de-energized, operation is
proportional.
Refer to Multiblock on page 8
Pressure Defeat (BPD) Option
H1, H2 Schematic
BPD Spool
U7
U6
T5
PCOR Valve
XA XB
Multiblock
The solenoid valve (M1) is available as a complete assembly only. Do not remove unless it is being
replaced.
11009446 • Rev BA • July 2014
Pressure Compensator OverRide (PCOR) Function
on page 9 for multiblock, PCOR and brake pressure defeat information.
Shuttle
A
T4
T6
B
M7
on page 8 and
Loop Flush
M4 M3
max.
disp.
T2 T3
T7
T8
T1
X1
P107 825
4-Way Valve
Brake
M1
L1
L2
M3 (M5)
M2
23