TSE DP20-4H, Owner'S Manual

Page: 49 / 242

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
MP1 controls are available with optional control passage orifices to assist in matching the rate of
swashplate response to the application requirements (e.g. in the event of electrical failure). 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. A swashplate response
table is available for each frame indicating available swashplate response times. Testing should be
conducted to verify the proper orifice selection for the desired response.
MP1 pumps are limited in mechanical orificing combinations. Mechanical servo orifices are to be used
only for fail-safe return to neutral in the event of an electrical failure.
Typical response times shown below at the following conditions:
Δp
250 bar [3626 psi]
Viscosity and temperature
30 mm²/s [141 SUS] and 50 °C [122 °F]
Charge pressure
20 bar [290 psi]
Speed
1800 min
-1
(rpm)
Response time, EDC
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.
Unintended MOR operation will cause the pump to go into stroke. The vehicle or device must always be
in a safe condition (i.e. vehicle lifted off the ground) when using the MOR function. 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. The MOR should be engaged
anticipating a full stroke response from the pump.
W
Warning
An o-ring seal is used to seal the MOR plunger where initial actuation of the function will require a force
of 45 N to engage the plunger. Additional actuations typically require less force to engage the MOR
plunger. Proportional control of the pump using the MOR should not be expected.
Refer to the control flow table in the size specific technical information for the relationship of solenoid to
direction of flow.
Service Manual
MP1
Operation
© Danfoss | July 2017 AX00000244en-US0103 | 15