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14
Curtis 1268 Manual,
Rev. D
CONTACTOR, SWITCHES, and OTHER HARDWARE
Main Contactor
A main contactor is required for use with any 1268 controller. The main contac-
tor allows the controller and motor to be disconnected from the battery. This
provides a significant safety feature in that the battery power can be removed
from the drive system if a controller or wiring fault is detected. A single-pole,
single-throw (SPST) contactor with silver-alloy contacts is recommended for
use as the main contactor. The coils must be specified at the nominal battery
pack voltage, with a continuous rating.
Keyswitch and Run/Store Switch
The vehicle should have a keyswitch to enable/disable driving each time the
vehicle is used. The run/store switch, on the other hand, is typically located in
an out-of-the-way location and left on except when the vehicle will be stored
(during the winter, for example) or is being towed. The keyswitch and the run/
store switch provide current to drive the various coils as well as the controller’s
internal logic circuitry and must be rated to carry these currents.
Forward, Reverse, Mode Select, and Pedal Interlock Switches
These input switches can be any type of single-pole, single-throw (SPST) switch
capable of switching the battery voltage at 25 mA.
Circuitry Protection Devices
To protect the control circuitry from accidental shorts, a low current fuse (ap-
propriate for the maximum current draw) should be connected in series with
the battery feed to the run/store switch. Additionally, a high current fuse should
be wired in series with the main contactor to protect the motor, controller,
and batteries from accidental shorts in the power system. The appropriate
fuse for each application should be selected with the help of a reputable fuse
manufacturer or dealer. The standard wiring diagrams (see pages 8, 9) show
the recommended fuse locations.
Speed Sensor
A speed sensor is required for use with any 1268 controller. The speed sensor
must be of a pulse type, and must interface to the controller with an open col-
lector NPN transistor output. The most common sensor type will be a Hall
effect switch IC, such as the Allegro type UGN3132 or Micro Switch type
SS11; these work with an eight-pole (four pulses per revolution) ring magnet
attached to the motor shaft. Other pole configurations can be accommodated
by programming the Tacho Poles parameter to match the sensor magnet. Linear
output sensors such as PM tachogenerators and variable reluctance gear tooth
sensors (“magnetic pickups”) are unsuitable.
A Curtis Application Note is available with more detailed information
on the speed sensor requirements.
2 — INSTALLATION & WIRING:
Switches, etc.