TM 55-1930-209-14&P-13
(4) Open (OFF) disconnect switch, disconnect wire from X1 at transformer and make continuity checks
as follows:
(a)
With ON button at bridge hand control held in, check continuity of circuit between point A
of magnetic coil CM and wire end of point X1. If open circuit exists, go to step (b). If
continuity exists, repair or replace wire from X2 to CM point B.
(b)
Check continuity of ON and OFF switches at bridge hand control between points A and B.
If continuity exists, go to step ©. If open circuit exists from either check, replace faulty
switch.
©
Check continuity of wires between points X1 and F7- B, F7-A and TB-X, TB-X and OFF
switch point A, OFF switch point B and ON switch point B, ON switch point A and TB1,
TB1 and CM point A, ON switch point B and CM point 1, and CM point 2 and CM point A.
Repair or replace any wires indicating an open circuit. If all wires indicate continuity,
replace contactor CM.
j.
Check voltage at inputs to fuses across terminal pairs 11 and 12, 11 and 13, and 12 and 13 for 440 Vac. If
voltage across all terminal pairs is 440 Vac, go to step k. If voltage across any terminal pair is not 440
Vac, repair or replace wire(s)
from contactor CM to fuses.
k.
Check voltage at inputs to contactor CM across terminal pairs K1 and K2, K1 and K3, and K2 and K3 for
440 Vac. f voltage across all terminal pairs is 440 Vac, go to step 1. If voltage across any terminal pair is
not 440 Vac, repair or replace wire(s) from fuses to contactor CM.
1.
With ON button at bridge hand control pushed, lockout relays 1 LS and 2LS OPEN and FORWARD
pushed, check voltage at outputs of contactor 1 M across terminal pairs J1 and J2, J1 and J3, and J2 and
J3 for 440 Vac. If voltage across any terminal pair is not 440 Vac, perform steps (1) and (2), below, as
necessary. If voltage across all terminal pairs is 440 Vac, go to step m.
(1) Check voltage at contactor 1 M across points A and B for 1 5 Vac. If voltage is 1 5 Vac, replace
contactor 1 M. If voltage is not 115 Vac, go to step (2).
(2) Check voltage at lockout relay 1CR for 115 Vac. If voltage is 115 Vac, replace lockout switches 1 LS
and/or 2LS.
m.
Check voltage at inputs of contactor 2M across terminal pairs L1 and L2, L1 and L3, and L2 and L3 for 440
ac. If voltage across all terminal pairs is 440 Vac, go to step n. If voltage across any terminal pair is not
440 Vac, repair or replace wire(s)
n.
With ON button at bridge hand control pushed, lockout relays 1 LS and 2LS OPEN and REVERSE button
pushed,checkvoltageatoutputsofcontact2M across terminal pairs M1 and M2, M1 and M3, and M2and M3
for 440 Vac. Perform steps (1) and (2), below, as necessary.
(1) Checkvoltageatcontactor2M across points A and B for 115 Vac. If voltage is not 115 Vac, go to step
(2). If voltage is 115 Vac, replace contactor 1 M.
(2) Open (OFF) disconnect switch, disconnect wire from X1 at transformer, and make continuity check
as follows:
WARNING
Make sure bridge crane motor controller is electrically dead before making continuity checks.
Redtag disconnect switch with: “WARNING - DO NOT ACTIVATE. REPAIRS BEING MADE.”
(a)
Check continuity of lockout relay 1 CR contact between points 4 and 2. If continuity exists, go
to step (b). If an open circuit exists, replace lockout relay 1CR.
(b)
Check continuity of contactor 1 M contact between points K4 and N4. If continuity exists, go
to step ©. If open circuit exists, replace contactor 1 M.
(c)
With reverse switch pushed, check continuity of reverse switch between points A and B. If
continuity exists, go to step (d)
If open circuit exists, replace reverse switch.
(d)
Check continuity of all wires in reverse drive control circuit from reverse switch to B-OL’S.
Also check continuity of any jumper wires in hand control station. Repair or replace any wires
that indicate an open circuit.
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