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29
Curtis 1268 Manual,
Rev. D
resulting voltage must be set high enough to hold the relay closed under all
shock and vibration conditions the vehicle will be subjected to. Low settings
minimize the current required to power the coil, thereby reducing coil heating
and increasing battery life.
Values for
AUX HOLDING
should be determined with specifications or advice
from the relay or brake manufacturer.
Example: To use a 24V brake in a 48V vehicle, try
AUX PULL IN
= 2 (28.8V)
AUX HOLDING
= 3 (16.8V)
EMB DELAY
The
electromagnetic brake dropout delay
sets a delay time before the EM
brake drops. The delay countdown begins either (1) when the vehicle has come
to rest and the main contactor has opened or (2) during field braking, when
the vehicle has slowed below the
FLD BRK SPD
.
Related parameter:
The
FLD BRAKE
parameter defines when the EM brake
delay will begin—see (1) and (2) above.
EMB SPD CHECK
The
electromagnetic brake speed check
parameter adds extra measures to
prevent the locking of the EM brake at high vehicle speeds under conditions
when the main contactor is open (for example, if the keyswitch is turned off
during driving or a fault is detected). When it is enabled, the controller over-
rides the
EMB DELAY
in an attempt to allow the vehicle to slow down prior to
engaging the EM brake.
EMB SPD VALUE
The
electromagnetic brake at speed value
parameter sets the speed at which
the EM brake is permitted to lock. It is programmable from 0 to 40.0 mph,
and is typically set at the extreme low end of that range. The purpose of
EMB
SPD VALUE
is to prevent dropping the EM brake at high speed, which could be
dangerous on certain terrain (e.g., wet grass).
In the event of main contactor failure (or fault detection that commands
the contactor to open) the EM brake parameters control the brake as follows.
EMB SPD CHECK
=
off
EM brake driver will turn off after
EMB DELAY
time has expired.
EMB SPD CHECK
=
on
EM brake driver will not turn off until vehicle speed is detected
as having reduced to the set
EMB SPD VALUE
.
If
EMB SPD VALUE
is set below 1.0 mph, the EM brake driver will
not turn off until the vehicle reaches rest.
3 — PROGRAMMABLE PARAMETERS: Output Driver Parameters