Specifications

Curtis PMC 1223/33, 1225/35, 1227/37 Manual
26
2 — INSTALLATION & WIRING: Switches, etc.
If momentary switches are being used, the controller will drive the LEDs
from an internal source. If on/off switches are used, the Direction LED and
Mode Indicator LED are powered directly from the switches and only the Status
LED is driven by the controller.
If indicator LEDs are used, they should be installed with the proper resistors
in series. The controller’s LED drivers are capable of providing a maximum
current of 30 mA. The recommended resistors — designed to limit driver current
to 15 mA when active — are listed in Table 3.
Horn
The controller’s horn driver — Pin 9 — is designed to drive a piezoelectric horn.
The horn sounds a warning when the reverse direction is selected (a series of beep
tones) and when the throttle autocalibration feature is being used (a constant
tone).
The horn driver provides a maximum current of 30 mA. Using a horn with
a higher current requirement will damage and disable the driver.
Main Contactor
An external main contactor is required with the 1227/37 controllers, and is shown
in their wiring diagrams (Figures 9 and 10). A heavy-duty single-pole, single-
throw (SPST) contactor with silver-alloy contacts is recommended, such as an
Albright SW80 or SW180. This contactor does not require an external precharge
resistor, because of the controllers’ built-in precharging feature.
Circuitry Protection Devices
To protect the control wiring from accidental shorts, a low current fuse (appro-
priately sized for the maximum control circuit current draw) should be connected
in series with the battery feed. A fuse is also recommended for use in the high
power connection from the battery to the controller’s B+ terminal. This fuse will
protect the power system from external shorts and should be sized appropriately
for the maximum rated current of the controller.
Table 3 RESISTORS FOR INDICATOR LEDs
RESISTOR POWER
VOLTAGE VALUE RATING
24V 1.5 kΩ 0.5 W
36V 2.4 kΩ 1.0 W
48V 3.3 kΩ 2.0 W