Wesley BCT-6200-6SA User Manual

Page 72

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Curtis 1243

GEN

2 Manual,

Rev. B

64

5 — VEHICLE PERFORMANCE ADJUSTMENT

STEP

2. If the transition is too abrupt: increase the Taper Rate and/or set

the Variable Braking parameter to On. Secondary adjustments
can be made by increasing the Accel Rate.

STEP

3. If the transition is too slow: decrease the Taper Rate and set

Creep Speed to 5% or greater. Secondary adjustments can be
made by decreasing the Accel Rate, increasing the Current Ratio,
or increasing the Quick Start parameter value.

8

Ramp Climbing

The vehicle response to increased gradients such as loading ramps can be tuned
via the Field Map parameter. Decreasing the Field Map parameter allows faster
vehicle speeds while climbing ramps, but it also has the effect of reducing the
ability of the controller to generate torque in the vehicle’s mid range speeds.

STEP

1. If faster vehicle speed is desired when climbing ramps, decrease

the Field Map parameter value until the desired ramp climbing
speed is attained. It should be noted that if the motor’s torque
capability is exceeded under the conditions of load weight and
ramp gradient, vehicle speed will be limited by the motor’s capa-
bility and the desired vehicle speed may not be attainable. The
system will find a compromise point at which sufficient motor
torque is generated to climb the ramp at an acceptable speed.
If the Field Map parameter value is reduced to 0% and the de-
sired speed is still not attained, the system is being limited by
the motor’s torque capability under these operating conditions.

CAUTION:

be careful when reducing the Field Map parameter

since at low Field Map values it is possible that the motor could
be operated outside its safe commutation region.

STEP

2. If the drive system cannot produce sufficient torque for a fully

loaded vehicle to climb the desired ramp, try increasing the Field
Map, Field Max, and/or Drive Current Limit parameters. The
impact of increasing these parameter values on other driving
characteristics must be evaluated. Increasing the Field Max will
provide more field current, and increasing the Drive Current
Limit will provide more armature current. If the Field Max is
set at the manufacturer’s specified limit and the Drive Current
Limit is set at the rated maximum, then vehicle speed up the
ramp is limited by the motor or the vehicle’s gearing and cannot
be increased by tuning the controller.

NOTE

: To determine if

the controller’s armature current is at its set value during ramp
climbing, read the “Arm Current” in the programmer’s Monitor
Menu.

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