Controller heatsink / motor cooling fan
An external fan to cool the controller heatsink or a motor may be connected to one of the analogue
outputs. The fan will be turned on by the controller when either the heatsink temperature or the motor
temperature exceed a specified temperature. The fan turns off when the nominated temperature is cold.
The temperatures at which the fans should turn on and off, the analogue output to use for the fan, the fan
voltage and the temperature source (heatsink or motor) can be programmed using the heatsink fan
object (5A01
h
). Note that the contactor driver outputs may be damaged if connected to capacitive loads.
It is quite common for fans to incorporate capacitive elements, in which case a relay should be used to
isolate the fan from the contactor driver output.
NOTE: The temperature set-point to turn on the fans should be higher than the set-point to turn off the fans
The fans will not operate if another function is configured to run on the specified analogue output.
Motor over-temperature protection
The controller protects motors from over-temperature. It maintains a motor temperature estimate and
can also accept a direct temperature measurement via an analogue input (for a thermistor) or a digital
input (for an over-temperature switch).
The temperature estimate is calculated by monitoring current to the motor over time. The estimate is
configured at 4621
h
.
The estimate is always applied, since it can detect increases in motor temperature more quickly than the
direct measurement. Direct measurement is normally done on the motor casing, which lags behind the
internal temperature.
Additional protection is provided for thermistor wire-off conditions. If the temperature sensor input
measures a completely short circuit or open circuit signal, then the output torque will begin to reduce
gradually over time. A recovery rate can also be specified should the signal become valid again. This
means that wire-off situations, should they occur during drive, do not result in an instant loss of torque.
Both the torque ramp down and recovery rates can be configured using object 4620
h
.
Motor over-speed protection
A facility to protect the motor or vehicle power train due to damage by over-speeding is available on the
controller. A maximum speed can be configured at object 4624
h
. Under normal operation the controller
should output braking torque to prevent the over-speeding initially, if the measured speed exceeds this
limit then the controller will shut down and a fault will be set.
CAUTION: The trip speed offers a final level of protection for the vehicle mechanics, and should be set
to a minimum level that would not be expected to be reached under normal operation.
Battery protection
The nominal battery voltage must be set at 2C00
h
.
Over voltage
Battery over voltage usually occurs during regenerative braking.
To provide protection set values for these parameters at 2C01
h
:
• Over voltage start cutback: the value at which the braking effort is linearly reduced to limit voltage
increase.
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