Troubleshooting And Bench Testing; Operational Notes - Curtis 1204 Manual

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Curtis PMC 1204/1205 Manual
TROUBLESHOOTING
AND BENCH TESTING
Some behaviors that may seem to suggest controller malfunction do not, in fact,
indicate a problem but rather are typical of normal operation. Before under-
taking the diagnostic tests, check to see whether your problem is addressed in
the first section, "Operational Notes." The diagnostic tests are designed to
enable you to determine whether the trouble is in the controller or in some other
part of the motor control circuitry. The controllers themselves are sealed
and not field serviceable; contact your local Curtis PMC service center
if the problem is in the controller. The diagnostic section provides enough
detail to enable you to track circuitry problems to their source and repair them.
Finally, the bench tests will allow you to confirm controller operation in a
simple, low-power test configuration. Bench testing is primarily intended for
checking out a number of controllers on a regular basis.

OPERATIONAL NOTES

Noise
Controller operation is normally silent. An exception is that a 1 kHz tone
may be heard during plug braking. This noise is normal and indicates that
plugging is taking place. The noise will stop when plug braking stops.
Inability of Vehicle to Plug Brake to a Stop on a Steep Ramp
If the vehicle is rolling backwards down a steep ramp in reverse and the
throttle is applied demanding forward drive, the controller will attempt to
plug the vehicle to a stop. If the ramp is so steep that the plugging current
setpoint is insufficient to stop the vehicle, it will continue to be braked but
will nevertheless roll down the ramp. If the mechanical brakes are applied,
and the vehicle is stopped, the full drive current will be available when the
throttle is applied and the vehicle will proceed up the ramp.
Sluggish Vehicle Behavior
Loss of power will be noticeable when the batteries become overly
discharged. This is a normal response to low battery voltage. Curtis PMC
1204/1205 controllers are designed to protect against damage caused by
low batteries. On 24–36 volt controllers, for example, power to the motor
is cut back when the voltage goes below 16 volts. Refer to the specifica-
tions (Appendix C) for other models.
TROUBLESHOOTING & BENCH TESTING
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