Vestil EPT-30 - Manual (Page 20)

20
Curtis PMC 1207/1207A Manual 13
As with the 2-wire throttles, broken wire protection is provided by the
controller looking for a minimum current into the Pot Low pin. If the Pot Low
input current falls below 0.1 mA, a throttle fault is generated and the controller
shuts down.
NOTE : The Pot Low pin (Pin 7) must not be tied to ground.
2 — INSTALLATION & WIRING: 1207 Controller
Fig. 9 Wiring for 3-wire
potentiometer throttle
(“Type 2”).
8 7 6 5 4 3 2 1
16 15 14 13 12 11 10 9
OFF ON
3-WIRE POT
Pin 7
Pin 6
Pin 5 Pot Low
0–5V Input
Pot High
PIN KEY (1207)
3-Wire Potentiometer (500 Ω–10kΩ) Throttle
A 3-wire potentiometer with a total resistance value anywhere between 500
Ω and
10k Ω can be used, wired as shown in Figure 9. The pot is used in its voltage
divider mode—with the voltage source and return being provided by the 1207
controller. Pot High provides a current-limited 5V source to the potentiometer,
and Pot Low provides the return path.