Product Manual

21
20.0 Troubleshooting the VOLT series Hoist
Table 7
Important: Any servicing performed on the brake, inverter, or other electrical components must be done by
qualified persons only.
Trouble Probable Cause Suggested Remedy
Hoist will not respond
to controls. Limit switch is tripped.
Move hook in opposite direction. If limit
switches need adjustment, have
qualified person inspect them.
Hoist overloaded. Reduce load to within rated capacity.
No incoming power, or low voltage.
Check hoist connections to power
source. If low voltage, have certified
electrician check incoming power.
Fuse blown or circuit breaker tripped. Replace fuse/re-set circuit breaker.
Incorrect phasing (230 volt model). Switch any two of the three supply wires.
Thermal overload relay is tripped. See “Motor overheats” below.
Brake won’t release; or rectifier
damaged in the phase protector.
Inspect continuity in brake; replace
phase protector.
VFD (inverter) malfunction.
Check fault codes. Contact JET
technical service.
Control contacts not opening/closing
properly.
Check electrical continuity; replace any
defective parts.
Motor malfunction.
Have motor inspected by a qualified
service technician; repair or replace as
needed.
Hoist operates only
intermittently.
Loose connectors; poor contacts; arcing. Inspect all wiring and contacts.
Broken conductor in control cord
Test continuity of each conductor.
Replace cable if needed.
Hoist lifts but will not
lower.
Broken conductor in control cord.
Test continuity of each conductor.
Replace cable if needed.
Up/down switch malfunctioning. Repair or replace switch.
VFD malfunction.
Check fault codes. Contact JET
technical service.
Hoist lowers but will not
lift.
Hoist overloaded. Reduce load to within rated capacity.
Up/down switch malfunction. Repair or replace switch.
VFD malfunction.
Check fault codes. Contact JET
technical service.
Load continues drifting
down excessively when
hoist is stopped.
Hoist overloaded. Reduce load to within rated capacity.
Brake out of adjustment.
Adjust brake air gap. Replace brake
lining if worn.
Grease or oil on the lining.
Open hoist, disassemble brake and
clean the lining (qualified persons only).
Brake springs are damaged. Replace brake springs.
Hoist moves in wrong
direction.
Incorrect phasing (230V model). Switch any two of the three supply wires
Variable speed dial not
functioning.
See probable causes under “Hoist will
not respond to controls.”
See “Hoist will not respond to controls.”
VFD malfunction.
Check fault codes; repair or replace as
needed. Contact JET technical service.
Motor overheats. Excessive load or too frequent use; or
affected by ambient temperature
Operate within rated load and according
to duty cycle rating. Limit use of hoist in
ambient temperatures over 104°.
Poor engagement of
chain with
sprocket/sheave.
Load chain is considerably worn. Replace load chain.
Sprocket wheel, sheave or chain guide is
considerably worn.
Replace parts as needed.