Curtis PMC 1297 Manual
A-7
APPENDIX A: GLOSSARY
distance, outdoor travel. The following six parameters can be set independently
in the two modes:
— acceleration rate
— braking current limit
— braking rate
— deceleration rate
— drive current limit
— maximum speed.
The operator uses the mode switch to select Mode 1 (switch open) or Mode 2
(switch closed).
Multiplexer (MUX)
The Curtis PMC 1312 tiller multiplexer provides a 4-wire serial interface for all
tiller functions. The typical wiring configuration for applications using the
multiplexer is shown in Figure 4, page 10.
OEM
(= Original Equipment Manufacturer)
Overtemperature
Because of their efficiency and thermal design, Curtis PMC controllers should
barely get warm in normal operation. Overheating can occur, however, if the
controller is undersized for its application or otherwise overloaded. The 1297
controller constantly monitors its internal heatsink temperature. Starting at
85
°
C, the armature current is linearly decreased from full set current down to
zero at 95
°
C.
NOTE
: Braking current limits are not reduced in overtemperature;
this ensures that full vehicle braking is available under all thermal conditions.
Full current and performance return automatically after the controller
cools down. Although occasional overtemperature operation is usually not
damaging to the controller, it does suggest a mismatch. If thermal cutback
occurs often in normal operation, the controller is probably undersized for the
application and a higher current model should be used. Continuous operation
in overtemperature will overstress the power components and reduce the
lifetime and reliability of the controller.
Overvoltage protection
The overvoltage protection feature protects the controller if the voltage exceeds
the factory-set limit. Overvoltage can result during battery charging or from an
improperly wired controller. As soon as the voltage rises above the overvoltage
threshold, the armature current is cut back linearly until it reaches zero at the
cutoff point; normal controller operation resumes when the voltage drops below
the threshold.
