Troubleshooting; Overview; Electrical Troubleshooting; Sluggish Operation - Danfoss H1B 060 Service Manual

Service Manual
H1 Bent Axis Motors, Size 060/080/110/160/210/250 cm3

Troubleshooting

Overview

Electrical troubleshooting

Check
1.
Motor operates at one
displacement only.
2. Erratic motor function

Sluggish operation

Check
1. Control orifices
2. Threshold setting (proportional
controls)
3. Control spool
4. Pressure compensator setting
5. Control input signal
6. Internal leakage

System operating hot

Check
1. Oil level
2. Heat exchanger
3. Loop flushing flow
4. Loop flushing shuttle
30 | © Danfoss | August 2018
This section provides general steps to follow if you observe undesirable system conditions. Follow the
steps until you solve the problem. Some of the items are system specific. Always observe the safety
precautions in the Introduction
W
Warning
Unintended movement of the machine or mechanism may cause injury to the technician or bystanders.
To protect against unintended movement, secure the machine or disable/disconnect the mechanism
while servicing.
Cause
Control coil failure
Electrical connection to motor is intermittent.
Cause
Blocked or restricted orifice may cause sluggish
response. Orifices installed in the wrong locations
may cause PCOR control to be sluggish.
Inappropriately high or low threshold setting may
shift the motor at the wrong time.
A sticky control may cause sluggish response or no
response.
Low pressure compensator setting may shift motor
to maximum displacement at lower pressure.
An improper or erratic input signal to the control
may cause sluggish response.
Excessive leakage will cause lower charge pressure
and affect performance.
Cause
Insufficient hydraulic fluid may cause overheating.
Blocked heat exchanger or low air flow may cause
system overheating.
Restricted orifice in loop flushing cartridge reduces
flow.
Loop flushing shuttle may be sticking in one
direction.
section.
Corrective action
Measure resistance at coil pins. Resistance at 20°C
[70°F] should be:
•
Proportional controls: 14.20 Ω (24V) or 3.66 Ω (12V)
•
Two-position controls: 8.4 Ω (24V) or 34.5 Ω (12V)
Replace coil if necessary.
Disconnect connector, check wires and terminals,
reconnect wires. Check terminals for corrosion and
correct position.
Corrective action
Remove, inspect and clean all orifices. Ensure the
appropriate orifices are installed and in the correct
location.
Check threshold setting. Adjust if necessary.
Clean and inspect the control spool. Replace if
necessary.
Check pressure compensator setting. Adjust if
necessary.
Check input signal and correct if necessary.
Install loop flushing defeat option and measure case
flow. If case flow is excessive, motor may require major
repair. Contact your Danfoss authorized service
center.
Corrective action
Fill reservoir to proper level.
Check temperature upstream and downstream of heat
exchanger. Clean, repair, or replace heat exchanger if
necessary.
Measure case drain flow. Clean or replace orifice
cartridge.
Ensure shuttle moves freely in its bore.
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