TM 5-3431-200-15
tacts with a fine file; replace missing
56. Rectifier
hardware and a damaged relay.
c. Testing.
(1) Use a multimeter set on suitable
the rectifier.
Warning: When a malfunction of the se-
ohm scale and touch the probes of the
multimeter to the trigger switch re-
lenium rectifier occurs, thoroughly ventilate
lay coil terminals.
the area to prevent inhalation of poisonous
(2) The multimeter should register 6,050
fumes. Do not handle the damaged rectifier.
ohms 5 percent resistance.
Selenium oxide may be absorbed through the
(3) Replace a relay which does not meet
skin, especially when the rectifier is hot. Failure
the above test specifications.
to observe this warning can result in severe
illness or death.
stall the trigger switch relay.
b. Cleaning and Inspection.
(1) Clean the rectifier with a dry, lint-
free cloth or with dry compressed air.
58. Inching Switch Relay
(2) Inspect for breaks, cracks, loose or
missing terminal connections, and
the inching switch relay.
frayed or broken insulation on elec-
b. Cleaning and Inspection.
trical leads. Tighten or replace loose
(1) Clean the relay with a dry, lint-free
or missing terminals. Replace the
cloth or with dry compressed air.
rectifier if damaged.
(2) Inspect for corroded contacts, missing
c. Testing. Perform the following rectifier
terminal hardware, worn or stripped
threads, and general deterioration.
(1) Place the probes of an ohmmeter on
Clean contacts with a fine file; replace
missing hardware and a damaged re-
one sc terminal and one dc terminal
lay.
of the rectifier. Position the ohmme-
ter for X100 ohms and note the read-
c. Testing. Follow the same procedure to
ing on the ohmmeter scale.
test the inching switch relay as that given for
testing the trigger switch relay in paragraph
(2) Reverse the probes on the two ter-
minals and note the reading.
57. The values are identifical.
(3) Compare the two readings. Replace
stall the inching switch relay.
the rectifier if the high reading is less
than 10 times greater than the low
reading.
59. Inching Feed, Inching Speed, and
Contractor Resistors
(4) Repeat (l), (2), and (3) above to
test the rectifier through the remain-
ing ac and dc terminals.
the inching feed, inching speed, and contac-
tor resistors.
stall the rectifier on the control panel.
b. Cleaning and Inspection.
(1) Clean with a dry, lint-free cloth or
57. Trigger Switch Relay
dry compressed air.
(2) Inspect for corrosion, deterioration,
a. Removal. Refer to figure 16 and remove
and worn or stripped threads on
the trigger switch relay.
mounting and terminal hardware.
b. Cleaning and Inspection.
Replace darnaged or defective parts.
(1) Clean the relay with a dry, lint-free
cloth or dry compressed air.
c. Testing. Use a multimeter set on appro-
(2) Inspect for corroded contacts, missing
priate ohm scale and touch the probes to the re-
terminal hardware, worn or stripped
sistor terminals. The inching feed resistor
threads, and deterioration. Clean con-
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