# Controller Safety



## Guest (Jun 12, 2011)

Integrated Safety Features
The DC750 contains an intelligent, multiple redundant failsafe system to provide a high degree of safety. The vehicle will shut down on any fault as a precaution.
Safe Start:
The start sequence begins when the ignition switch is turned on. Upon every power up, the DC750 tests for shorts and looks at various internal and external control points, such as voltages and temperatures. The throttle must be in a zero state before the drive mode is enabled to prevent unintended movement. Low traction pack voltage also prevents vehicle operation.
Contactor Control:
The DC750 will activate the contactor when the system successfully completes the safe start sequence. The contactor will remain enabled unless there is a critical fault or if the ignition switch is turned off. The contactor drivers and the pre-charge circuit are all built into the DC750, eliminating the need for any external accessories on the contactor. In addition the contactor control is powered by the key switch thereby providing a manual override disconnect in the event of a runaway condition.
Open Throttle Input:
The DC750 will fault if the throttle signal goes out of range due to faulty wiring or hardware. This also is to prevent a runaway condition.
Priority Braking:
The DC750 assigns priority to the brake in the event that both the brake and throttle are applied simultaneously.
Direction Change Lockout:
The DC750 will not allow the vehicle direction to be changed via a reversing contactor unless the vehicle has come to a full stop and the throttle is at zero. Only then will the DC750 enable the reversing contactor.
Reverse Power Limit:
The DC750 allows for separate speed when in reverse which is useful with vehicles not using a mechanically reversing transmission.
Temperature Monitoring:
The DC750 will limit the current output of the controller in a linear fashion as the internal temperature rises above the normal safe level.
Battery Voltage Monitoring:
The DC750 will limit the current output of the controller when the traction pack voltage is low.


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