Danfoss H1T 045 User Manual

Electrical Troubleshooting
Electrical troubleshooting
Item Description Action
Control operates pump in
one direction only.
Control coil failure
•
Measure resistance at coil pins. Resistance should be
14.20 Ω (24V) or 3.66 Ω (12V) at 20°C [70°F].
•
Replace coil.
No pump function No power to controller Restore power to controller.
Erratic pump function Electrical connection to pump is bad. Disconnect connection, check wires, reconnect wires.
Filter bypass indicator switch Filter switch may be bad.
•
Check/replace filter switch.
•
Add gauge to filter bypass port to verify proper fluid flow
and verify switch operation by measuring resistance.
‒
Open resistance ≥ 510 Ω
‒
Closed resistance ≤ 122 Ω
Erratic or no machine
function
External controller malfunction or hydraulic system
problem.
•
Verify external controller problem using spare controller.
•
Replace controller.
•
Check hydraulic system fluid level/pressures/filters/etc.
•
Fix hydraulic system problems.
Use a manual override to check proper pump operation and verify electrical problem, if available.
Integral Filter Bypass
Item Description Action
Filter bypass activated Filter is plugged causing fluid to bypass filter. Replace filter. Check that bypass switch indicates proper
operation after filter is replaced.
Filter bypass indicator switch Filter bypass indicator switch is indicating wrong bypass
situation.
Check/replace filter switch.
•
Open resistance ≥ 510 Ω
•
Closed resistance ≤ 122 Ω
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 50).
•
If neutral is still impossible to set, balance the swashplate
(see Mechanical Neutral Adjustment on page 52).
•
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.
Service Manual
H1T 045/053, 060/068 Axial Piston Tandem Pumps
Troubleshooting
36 |
©
Danfoss | September 2020 AX152886481761en-000405

Danfoss H1T 045 Specifications

General

Brand	Danfoss
Model	H1T 045
Category	Water Pump
Language	English