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00001996 (REV AC) 627NH October 2014
TROUBLE SHOOTING ALL HOISTS TABLE 7
TROUBLE PROBABLE CASE REMEDY
8.) Motor overheats. A.) Low voltage. A.) Correct low voltage condition as
described on page 15.
B.) Excessive load. B.) See item 1H.
C.) Extreme external heating. C.) Above an ambient temperature of 40°C.
(104°F.), the frequency of hoist operation
must be limited to avoid overheating of
motor. Special provisions should be made
to ventilate the space or shield the hoist
from radiation.
D.) Frequent starting or reversing. D.) Avoid excessive inching, jogging
or plugging. This type of operation
drastically shortens the motor and
contactor life and causes excessive brake
wear.
E.) Phase failure or unbalanced current
in the phase (three phase unit only).
E.) See item 1B.
F.) Brake dragging. F.) Check brake adjustment as described on
page 22.
G.) 115-1-60 Units: Solid state reverse
switch exposed to excessive
temperature or the switch is
damaged.
G.) See page 21.
9.) Hook fails to stop at either or
both ends of travel.
A.) Limit switches not opening circuits. A.) Check switch connections, electrical
continuity and mechanical operation.
Check the switch adjustment as
described on page 15-16.
B.) Limit Switch Shaft not rotating. B.) Check for damaged Limit Switch gears.
C.) Traveling nuts not moving along
shaft guide plate loose; shaft or nut
threads damaged.
C.) Tighten guide plate screws. Replace
damaged part.
10.) Hook stopping point varies. A.) Limit switch not holding adjustment. A.) See item 9.
B.) Brake not holding. B.) Check the brake adjustment as described
on page 22.
C.) Binding of Limit Switch Shaft. C.) Check Limit Switch Bearing for proper
seating.
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