Troubleshooting; Excessive Noise And /Or Vibration; Low Pump Output Flow; No Or Low System Pressure - Danfoss D1 Series Service Manual

Service Manual
D1 High Power Open Circuit Pumps Size 65/130/145/193/260

Troubleshooting

Excessive Noise and /or Vibration

Low Pump Output Flow

No or Low System Pressure

32 | © Danfoss | July 2019
Item
Check fluid level in reservoir.
Check for air in system.
Check pump inlet pressure / vacuum. Improper inlet conditions cause
Inspect shaft couplings.
Check shaft alignment.
Hydraulic fluid viscosity above
acceptable limits.
Item
Check fluid level in reservoir.
Hydraulic fluid viscosity above
acceptable limits.
Check external system relief valve
setting.
Check pressure compensate (PC),
load sensing (LS) and power (T)
control setting.
Check LS control signal pressures.
Check Pilot pressure for hydraulics
displacement control and input
current for electric displacement
control.
Check pump inlet pressure / vacuum. High inlet vacuum causes low output
Check input speed.
Check pump rotation.
Item
Check pressure compensate (PC) and
power (T) control setting.
Check external relief valve.
Description
Insufficient hydraulic fluid causes
cavitation.
Air in system causes noisy, erratic
control.
erratic behavior and low output flow.
A loose or incorrect shaft coupling
causes excessive noise and / or
vibration.
Misaligned shafts create excessive
noise and / or vibration.
Hydraulic fluid viscosity above
acceptable limits or low fluid
temperature will not allow the pump
to fill or control to operate properly.
Description
Insufficient hydraulic fluid will limit
output flow and cause internal
damage to pump.
Fluid viscosity above acceptable
limits or low fluid temperature will
not allow the pump to fill or control
to operate properly.
External relief valve set below PC
setting causes low output flow.
Low PC setting prevents the pump
from achieving full stroke. Low LS
setting limits output flow. Low T
setting limits output flow.
Incorrect LS signal will not allow
pump to operate correctly.
Incorrect input signal causes low
output flow.
flow.
Low input speeds decrease flow.
Incorrect rotational configuration
causes low flow.
Description
Low PC and T setting leads to low
system pressure.
External relief valve setting below PC
setting.
Action
Fill the reservoir to proper level.
Purge air and tighten fittings. Check
inlet for leaks.
Correct pump inlet pressure /
vacuum conditions.
Repair or replace coupling and
ensure that correct coupling is used.
Correct shaft misalignment.
Allow system to warm up before
operating, or use fluid with the
appropriate viscosity grade for
expected operating temperatures.
Action
Fill the reservoir to proper level.
Allow system to warm up before
operating, or use fluid with the
appropriate viscosity grade for
expected operating temperatures.
Adjust external relief valve following
manufacturer's recommendation.
External relief valve setting must be
above PC setting to operate properly.
Contact Danfoss Service.
Inspect system to ensure that proper
LS signal transmit to pump.
Adjust input hydraulic or electric
signal to right value.
Correct inlet pressure conditions.
Adjust input speed.
Use pump with appropriate
rotational configuration.
Action
Contact Danfoss Service.
Adjust external relief valve according
to manufacturer's recommendations.
External relief valve must be set
above PC setting to operate properly.
L1527453 | AX00000292en-CN0201