Pump output flow direction vs. control signal
Shaft rotation
CW
CCW
Coil energized
*
C1
C2
C1
C2
Port A
out
in
in
out
Port B
in
out
out
in
Servo port pressurized
M4
M5
M4
M5
*
For coil location see Installation drawings.
Control Response
H1controls are available with optional control passage orifices to assist in matching the rate of swash-
plate response to the application requirements.
The time required for the pump output flow to change from zero to full flow (acceleration) or full flow to
zero (deceleration) is a net function of spool porting, orifices, and charge pressure.
H1 pumps are limited in mechanical orifice combinations. Mechanical servo orifices are to be used only
for fail-safe return to neutral in a case of an electrical failure.
A swash-plate response times table is available for each frame size. Testing should be conducted to verify
the proper orifice selection for the desired response. Typical response times at the following conditions:
Δ p = 250 bar [3626 psi]
Charge pressure = 20 bar [290 psi]
Viscosity and temperature = 30 mm²/s [141 SUS] and 50 °C [122 °F]
Speed = 1800 min
-1
(rpm)
MP1 EDC response time
Stroking direction
0.8 mm [0.03 in]
orifice
1.0 mm [0.04 in]
orifice
1.3 mm [0.05 in]
orifice
No orifice
28/32
38/45
28/32
38/45
28/32
38/45
28/32
38/45
Neutral to full flow
1.3 s
2.1 s
0.9 s
1.3 s
0.6 s
0.9 s
0.4 s
0.6 s
Full flow to neutral
1.0 s
1.5 s
0.7 s
0.9 s
0.4 s
0.6 s
0.2 s
0.3 s
Manual Over Ride (MOR)
Electro-hydraulic controls are available with a Manual Over Ride (MOR) either standard or as an option for
temporary actuation of the control to aid in diagnostics.
Initial actuation of the o-ring seal MOR plunger will require a force of 45 N. Additional actuations typically
require less force to engage the MOR plunger. Proportional control of the pump via the MOR is not
intended. The MOR plunger has a 4 mm diameter and must be manually depressed to be engaged.
Depressing the plunger mechanically moves the control spool which allows the pump to go on stroke.
Unintended MOR operation can cause the pump to go into stroke.
The vehicle or device must always be in a safe condition (example: vehicle lifted off the ground) when
using the MOR function. The MOR should be engaged anticipating a full stroke response from the pump.
Refer to control flow table for the relationship of solenoid to direction of flow.
Service Manual
MP1
Operation
16 |
©
Danfoss | April 2019
AX00000244en-000201