Wesley BCT-6200-6SA - Manual (Page 25)

Curtis 1243
GEN
2 Manual, Rev. B 17
CONTACTOR, SWITCHES, and OTHER HARDWARE
Main Contactor
A main contactor should be used with any 1243
GEN
2 controller; otherwise the
controller’s fault detects will not be able to fully protect the controller and mo-
tor drive system from damage in a fault condition. The main contactor 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 results in full battery power being
applied to the motor. If the Contactor Diagnostics parameter (see Section 3,
page 40) is On, the controller will conduct a missing contactor check and a
welded contactor check each time the main contactor is requested to close and
will not proceed with the request if a fault is found.
A single-pole, single-throw (SPST) contactor with silver-alloy contacts,
such as an Albright SW80 or SW180—available from Curtis—is recommended
for use as the main contactor. The contactor coils should be specified with a
continuous rating at the nominal battery pack voltage.
The main contactor coil driver output (Pin 4) is rated at 2 amps, is over-
current protected, and is checked for open coil faults. A built-in coil suppres-
sion diode is connected between the main contactor coil driver output and the
keyswitch input. This protects the main contactor coil driver from failure due
to inductive voltage kickback spikes when the contactor is turned off.
Keyswitch and Interlock Switch
The vehicle should have a master on/off switch to turn the system off when not
in use. The keyswitch input provides logic power for the controller.
The interlock switch—which is typically implemented as a tiller switch,
deadman footswitch, or seatswitch—provides a safety interlock for the system.
The keyswitch and interlock switch provide current to drive the main
contactor coil and all other output driver loads as well as the controller’s internal
logic circuitry and must be rated to carry these currents.
Forward, Reverse, Mode Select, and Emergency Reverse Switches
These input switches can be any type of single-pole, single-throw (SPST) switch
capable of switching the battery voltage at 10 mA. Typically the emergency
reverse switch is a momentary switch, active only while it is being pressed.
Reverse Polarity Protection Diode
For reverse polarity protection, a diode should be added in series between the
battery and KSI. This diode will prohibit main contactor operation and cur-
rent flow if the battery pack is accidentally wired with the B+ and B- terminals
exchanged. It should be sized appropriately for the maximum contactor coil
and fault diode currents required from the control circuit. The reverse polarity
protection diode should be wired as shown in the standard wiring diagram,
Figure 3 (page 7).
2 — INSTALLATION & WIRING: Main Contactor & Switches, etc.