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 MDC response time
Code Orifice description (mm) Stroking direction (sec)
P A B Tank (A
+B)
Neutral to full flow Full flow to neutral
28/32 38/45 28/32 38/45
C3
– – – – 0.3 0.3 0.3 0.3
C6
– – – 1.0 0.5 1.0 0.5 0.7
C7
– – – 1.3 0.4 0.7 0.5 0.5
C8
0.8 – – 0.6 1.5 2.6 1.4 1.9
C9
1.0 – – 0.6 1.3 2.4 1.1 1.8
D1
1.0 – – 0.8 0.9 1.6 0.8 1.1
D2
1.3 – – 0.8 0.8 1.5 0.7 1.1
D3
1.3 – – 1.0 0.6 1.1 0.6 0.8
D4
1.3 1.3 1.3 1.0 0.8 1.3 0.7 0.9
D5
0.6 0.8 0.8 0.6 3.2 4.0 2.0 2.9
Neutral Start Switch (NSS)
The Neutral Start Switch (NSS) contains an electrical switch that provides a signal of whether the control
is in neutral. The signal in neutral is Normally Closed (NC).
Service Manual
MP1
Operation
22 |
©
Danfoss | April 2019 AX00000244en-000201
To Next Page
Loading...
Need help?
General
