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

306
see whether the faces of the bronze bushings
in the pump body and head have been scored.
An examination should be made of the rotor
vanes to see that no sheared particles of brass
have becomelodged beneath them. Whenthe head
is replaced the flange screws should be tightened,
while rotating the shaft manually.
(b) s a t n pump bind ing. - If a binding condition
exists in the A-end first check the gears which
drive the control pump to insure that no foreign
matter has become wedged in the gear teeth.
If binding still exists the A...:.endis to be
dismantled for inspection as explained in the
instructions of paragraphs 128, 129.
93. Hoist inoperative due to pressure failure when the
controls are set fo~ a hoisting cycle. -
(a) Failure of electrical control circuit. - With
the electric motor operating and the controls
correctly adjusted and positioned for a hoisting
cycle, using servo electrical control,
pressure should build up in the system as soon
as the starting handle is movedto the IIstart II
position. If pressure does not become available
immediately, it is probably due to the
failure of the electrical control circuit.
This may be checked by shifting the control
selector lever to the servo mechanical position.
If the hoist then functions correctly
and requires only a normal effort to shift the
control lever, the trouble is in the electrical
controls, and may be caused by one of the following
reasons:
(1) The solenoid fuse, in the controller box,
blown.
Check fuse and if blown replace with the
proper fuse.
(2) The door interlock switches open.
Check to see if doors at the top and
bottom of the hoist are closed. If
closed check the switches to see if they
are closed and the contacts in good condition.