Specifications

Curtis PMC 1223/33, 1225/35, 1227/37 Manual
18
2 — INSTALLATION & WIRING: Throttle
THROTTLE WIRING
The 1223/33, 1225/35, and 1227/37 controllers are programmable to suit a
variety of throttles. If the throttle you are planning to use is not covered, contact
the Curtis office nearest you.
Mounting dimensions are provided in Appendix B for the standard 5kΩ,
3-wire throttle potentiometer (manufactured for Curtis PMC by Clarostat), the
Curtis PMC potboxes and footpedals, and the electronic throttle ET-1XX
(manufactured for Curtis by Hardellet).
For information on programming various throttle parameters, see Section 3:
Programmable Parameters; the throttle parameters are on pages 33–39.
5kΩ, 3-Wire Potentiometer
A 5kΩ, 3-wire potentiometer is the standard throttle, and is shown in the basic
wiring diagrams (Figures 3 & 4, 6 & 7, and 9 & 10). The controller can be
programmed to be compatible with single-ended, wigwag, or inverted wigwag
style throttles (see page 33). These throttle styles are defined in Table 2 (page 19).
NOTE: The standard 8% neutral deadband and 100% throttle gain are assumed
in the definitions; resistance is measured between pot low and pot wiper.
For wigwag and inverted wigwag applications, the pot can be correctly
centered within the controller’s neutral band by using the throttle autocalibration
feature (see page 35). Pots with less than 5 kΩ total resistance change over the
throttle’s full stroke can be accommodated by programming the controller for
reduced-range throttle inputs, via the throttle gain parameter (see page 37).
The controller provides full pot fault protection against open or shorted
wires anywhere in the throttle assembly. The overall pot resistance can range
from 4.5 kΩ to 7.0 kΩ. Values outside this range will trigger a fault condition.
If a pot fault occurs while the vehicle is moving, the controller will decelerate the
vehicle to neutral through its normal deceleration curve. If the fault is corrected
while the throttle is still applied, the vehicle will accelerate to the requested speed.
0–5V Throttle
A 0–5V throttle input can be used instead of a pot, as shown in Figure 11. The
controller can be programmed to be compatible with single-ended, wigwag, or
inverted wigwag style throttles (see page 33). These throttle styles are defined in
Table 2 (page 19). With a wigwag or inverted wigwag 0–5V input, the throttle
output voltage must be 2.5 V (± deadband) in neutral and a 4.7kΩ, 0.25W
resistor must be added between the pot high and pot low pins. A resistor is not
required with a single-ended 0–5V input.
Voltage throttles with less than 5 V total voltage change over the full stroke
can be accommodated by programming the controller for reduced-range throttle
inputs, via the throttle gain parameter (see page 37).