Troubleshooting Guide - Enerpac ZU4 Instructions

9.0 TROUBLESHOOTING
Only qualifi ed hydraulic technicians should service the pump or system components. A system failure may or may not be the
result of a pump malfunction. To determine the cause of the problem, the complete system must be included in any diagnostic
procedure.
The following information is intended to be used only as an aid in determining if a problem exists. For repair service, contact your
local Authorized Enerpac Service Center.
Problem
Pump will not start.
Pendant does not function.
Motor stops under load.
Solenoid valve will not operate.
Pump fails to build pressure or less
than full pressure.
Pump builds full pressure, but torque
wrench does not advance.
Torque wrench does not auto-cycle
or cycles erratically.
Torque wrench will not retract.
Pump runs hot.
* Refer as needed to sections 6.6 and 6.7 for LCD fault codes and warnings.

Troubleshooting Guide*

Possible Cause
Fault condition.
Motor brushes worn to end of life
(ZU4 Models only).
Pump in LOCAL mode.
Pendant damaged.
Low voltage.
No power to pump or wrong voltage.
Solenoid cable disconnected or damaged.
Solenoid coil not operational.
Valve out of adjustment or malfunctioning.
Low oil level.
Relief valve set too low.
External system leak.
Internal leak in pump.
Internal leak in valve.
Internal leak in system component.
Torque greater than wrench capacity at full
pressure.
Advance fl ow to wrench restricted or
blocked.
Automode is OFF.
Relief valve setting at or below "HI PRESS"
value (or below the corresponding pressure
setting for the selected torque).
HI PRESS setting below 1400 PSI [96 bar].
Return fl ow line restricted or blocked.
Valve malfunction.
Advance or retract fl ow restricted.
High ambient temperature.
Action
See Section 6.6, LCD Fault Conditions.
See Section 7.3, Motor Brush Replacement.
See Section 6.5 M, Local Menu.
See Section 6.5 O, Diagnose Menu.
See authorized service center.
See Section 6.5 J and 6.7.
Turn off other electric loads.
Use heavier gauge extension cord.
Connect to correct power source per pump nameplate.
Connect, repair, or replace cable.
See authorized service center.
See authorized service center.
Add oil per Section 4.3.
Adjust per Section 5.2.
Inspect and repair or replace.
See authorized service center.
Use torque wrench with larger capacity.
Check couplers for full engagement per Section 4.5.
Turn Automode ON. See sections 5.3 and 6.5 D.
Increase relief valve setting. See Section 5.2.
Raise HI PRESS setting above 1400 PSI [96 bar].
Check couplers for full engagement per Section 4.5.
Run motor when retracting.
See authorized service center.
Check couplers for full engagement per Section 4.5.
Install heat exchanger.
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