Curtis PMC 1204X/1205X/1209/1221 Manual
26
TROUBLESHOOTING & BENCH TESTING
batteries. On 24–36 volt models, power to the motor is cut back when the voltage
goes below 16 volts. Refer to the specifications (Appendix C) for other models.
Hot Controller
If the controller gets hot, it does not necessarily indicate a serious problem. Curtis
PMC 1204X/1205X/1209/1221 controllers protect themselves by reducing
power to the motor if their internal temperature exceeds 75
°
C (167
°
F). Power
output will be reduced for as long as the overheat condition remains, and full
power will return when the unit cools.
In typical applications, overheating will rarely be a problem. However,
vehicle overloading may cause overheating, particularly if the controller is mounted
so that heat cannot be conducted away from its case or if other heat-generating
devices are nearby. If thermal cutback occurs often during normal operation, the
controller is probably undersized and should be replaced with a higher current
model.
IN-VEHICLE DIAGNOSTIC TESTS (TROUBLESHOOTING)
These tests require a general purpose volt ohmmeter. You can use either a
conventional “V-O-M” or an inexpensive digital voltmeter.
The troubleshooting chart (opposite) serves as a guide to the procedures that
follow. Before starting these tests, refer to the appropriate wiring diagrams and
make sure your controller is hooked up properly.
☞
C A U T I O N
Working on electric vehicles is potentially dangerous.
You should
protect yourself while performing the diagnostic tests by jacking up
the vehicle to get the drive wheels off the ground, opening the battery
circuit before working on the motor control circuit, wearing safety
glasses, and using properly insulated tools (see page 2).
