OP-755 Part 2 Pages 197-401 - Personal Page of GENE SLOVER

their source and making corrections . The' instructions are
based on normal operation of the hoist (Servo Electrical Control).
The various symptoms of imperfect functioning are indicated
by separate subheadings, under each of which is listed
the possible causes and the procedure to follow in restoring
the equipment to normal. The order of arrangement under
each subheading is designed to isolate the' source of the trouble
by a process of elimination and if the same sequence is
(~) followed in practice a minimum amount of work will be required.
\, J Where further Lnstr-uc t.Lons are required for removing parts,
refer to "Disassembly Instruction's". '
305
90. No electric power. - If electric motor fails to
start, current is probably not available due to one of the
causes mentioned below.
(a) Circuit breaker being open in the controller
box.
,( b) Pilot circuit fuse in the controller, box is
blown.
(c) Neutral tnt.er Lock sv.itell on the A-end Lnco r -
rectly connected' 6'r adj us ted , (See instructions
to adjust limit's.witch.)
Cd ) Main linefu~es blown.
91. Circuit breaker opens. - This would indicate a direct
short Lri the main circuit supply lines to the electric
motor.
92. Overload r e lay open. - If the electric motor tends
to start, but the overload relays in the controller box open,
the trouble' vrill probably be a' damaged A-end or control pump
causing a locked rotor. The pumps are to be checked for damage
by attempting to rotate the electric motor shaft manually.
If a binding condition exists remove the control pumpto check
whether the binding condition is in the control pump or in the
A-end p:wnp.
(a) Control pump binding. - If a binding condition
is found to exist in the control pump, the
loosening of the screws in the pumphead must
not be considered a sufficient correction.
The pump head must be removed, and an lnspection
made to see whether ,the pump has been
damaged by the starting action. The rotor
should be removed and an inspection made to