3-24. POWER CONTACTOR (cont)
Install power contactor assembly (4) and secure with two flat washers (3), lockwashers (2), and capscrews (1).
Connect electrical wires in accordance with wiring diagram.
High voltage is used in the operation of equipment. Do not be misled by the term LOW VOLTAGE.
Potentials as low as 50 volts may cause death.
Remove rings, bracelets, wristwatches, and neck chains before working around the locomotive. Jewelry
can catch on equipment and cause injury, or may short across an electrical circuit and cause severe burns
or electrical shock.
Connect a variable dc voltage to magnetic coil (74). Use a multimeter and attach leads of variable dc voltage
source. While applying voltage, check that the maximum pickup is 48 V dc. While decreasing voltage, note the
dropout point; it should be between 28 and 5 V dc.
Energize and deenergize relay and check that there is no hesitation during pickup or dropout.
Set battery switch to open position. Manually operate interlock contacts. Use a multimeter and check resistance
of contacts for infinity while open and continuity while closed.