44
Curtis 1268 Manual,
Rev. D
bk
WalkAway
™
Braking
If the WalkAway
™
option is configured, WalkAway
™
braking will occur whenever
vehicle movement is detected while the main contactor is open. In general this
is used to prevent uncontrolled vehicle rolling after the vehicle has reached rest.
It also is used to slow the vehicle if it is rolling when the keyswitch is turned
off or in certain fault conditions that cause the main contactor to open.
The strength of the WalkAway
™
braking is controlled by the
WALKAWAY C/L
and
PLUG C/L
parameters.
step
1. Drive the vehicle onto a steep grade, and hold it with the foot
brake until you hear the main contactor open.
step
2. Release the foot brake. The vehicle will begin to roll at a slow
pace, followed by WalkAway
™
braking (indicated by a beeping
tone).
If the vehicle is rolling too fast, increase the
WALKAWAY C/L
and/or the
PLUG C/L
.
step
3. Check that these braking parameter adjustments do not make
the braking feel too abrupt on milder slopes.
bl
Low-Speed Field Braking
The
FLD BRAKE
parameter provides an additional mechanism for slowing the
vehicle down at slow speeds. There are three uses for field braking:
a. Providing extra braking torque as the vehicle slows to a stop.
b. Strengthening the anti-rollback braking in vehicles that do not have
an EM brake.
Note: The anti-rollback function can never hold a
vehicle perfectly stationary on an incline and is not
intended to replace a mechanical or electromagnetic
brake for this purpose. However, it will prevent
uncontrolled vehicle coasting in this situation.
c. On vehicles equipped with an EM brake, field braking and the EM
brake can be used together to stop the vehicle and to prevent the vehicle
from rolling back down a hill.
Note: This use of field braking is covered separately
in Procedure
bm
.
This procedure tunes the field braking parameters to provide additional braking
at low speeds in situations (a) and (b).
5 — TUNING GUIDE