Danfoss H1P 069, Руководство по обслуживанию, Страница: 31 / 67

Neutral Difficult or Impossible to Find
Item Description Action
Input to pump control Input to control module is operating improperly Disconnect input and check to see if pump comes back to
neutral.
•
If Yes – input fault, replace or repair external controller
•
If No – go to next step
Neutral Neutral set improperl Shunt servo gauge ports (M4 and M5) together with
external hose and see if pump comes back to neutral.
•
If Yes – Control neutral improperly set (see Control
Neutral Adjustment on page 38).
•
If neutral is still impossible to set, balance the swashplate
(see Mechanical Neutral Adjustment on page 40).
•
If you still cannot set neutral, replace the control.
Transmission Operates Normally in One Direction Only
Item Description Action
Input to pump control. Input to control module is operating improperly. Check control input and repair or replace as necessary.
Control orifices Control orifice(s) are blocked. Clean control orifices.
Control screens Control screen(s) are blocked. Replace control screens. Only a Danfoss Authorized Service
Center may remove the unit’s endcap without voiding the
warranty.
Exchange system pressure
limiters Exchanging the pressure limiter valves will show if the
problem is related to the valve function. If the problem changes direction, replace the valve that
does not operate correctly.
Exchange high pressure
relief valves Exchanging the high pressure relief valves will show if the
problem is related to the valve function. If the problem changes direction, replace the valve that
does not operate correctly.
Servo pressure low or
decaying Damaged servo seals may prevent servo piston from
stroking the pump. Check for torn/missing servo seals. Replace and retest. Only
a Danfoss Authorized Service Center may remove the servo
piston without voiding the warranty.
Bypass function open Open bypass will cause one or both directions to be
inoperative. Close bypass function.
System Operating Hot
Item Description Action
Oil level in reservoir
Insufficient hydraulic fluid will not meet cooling demands
of system.
Fill reservoir to proper level.
Heat exchanger
Heat exchanger is not sufficiently cooling the system.
•
Check air flow and input air temperature for heat
exchanger
•
Clean, repair or replace heat exchanger
Charge pressure Low charge pressure will overwork system.
•
Measure charge pressure.
•
Inspect and adjust or replace charge relief valve.
•
Inspect charge pump; repair or replace charge pump.
Charge pump inlet vacuum
High inlet vacuum will overwork system.
A dirty filter will increase the inlet vacuum. Inadequate line
size will restrict flow.
•
Check charge inlet vacuum. If high, inspect inlet filter
and replace as necessary
•
Check for adequate line size, length or other restrictions
System relief pressure
settings
If the system relief valves are worn, contaminated, or valve
settings are too low, the relief valves will be overworked.
Verify settings of pressure limiters and high pressure relief
valves and adjust or replace valves as necessary.
System pressure
Frequent or long term operation over system relief setting
will create heat in system.
Measure system pressure. If pressure is too high, reduce
loads.
Service Manual
H1P 069—H1P 280 Axial Piston Single Pumps
Troubleshooting
© Danfoss | January 2021 AX152886482551en-000601 | 31