Vestil EPT-30 - Manual (Page 57)

57
Curtis PMC 1207/1207A Manual A-2
APPENDIX A: GLOSSARY
Contactor drivers and circuits
These controllers can accommodate up to four external contactors: forward,
reverse, main, and shunt. Some vehicles may have no main contactor, or the main
contactor may be wired directly to the KSI or brake signal, bypassing the
controller.
Various protections provided for the contactor drivers ensure that the
contactors operate correctly; see Fault detection.
The shunt winding of a compound motor can be wired directly to the shunt
driver, provided that the maximum current does not exceed the driver’s current
rating.
Creep speed at first throttle
Creep speed is activated when a direction is first selected. The output maintains
creep speed until the throttle is rotated out of the throttle deadband (typically
10% of throttle). Creep speed is adjustable from 0 to 25% of the controller duty
factor; the adjustment can be made mechanically (via the appropriate trimpot on
top of the 1207 controller) or electronically (via the handheld programmer).
Current limiting
Curtis PMC controllers limit the motor current to a preset maximum. This
feature protects the controller from damage that might result if the current were
limited only by motor demand. PWM output to the power section is reduced
smoothly until the motor current falls below the set limit level.
In addition to protecting the controller, the current limit feature also
protects the rest of the system. By eliminating high current surges during vehicle
acceleration, stress on the motor and batteries is reduced and their efficiency
enhanced. Similarly, there is less wear and tear on the vehicle drivetrain, as well
as on the ground on which the vehicle rides (an important consideration with golf
courses and tennis courts, for example).
If you have a MultiMode™ controller, the main current limit, plug current
limit, and ramp start current limit in Mode 1 and in Mode 2 are independently
adjustable via the handheld programmer. If you have a 1207 controller with the
MultiMode™ feature disabled (i.e., a single-mode controller), you can adjust the
main and plug current limits mechanically via the appropriate trimpots located
on top of the controller.
In addition, the emergency reverse current limit can be set via the handheld
programmer.