7- 12SPM Synchronous Motor Protection & Control GE Power Management7.6 DOs AND DON’Ts 7 TESTING AND TROUBLESHOOTING77.6 DOs AND DON’Ts 7.6.1 DOs1. Always connect the MX input up to an auxiliary 'b' contact from the motor contactor.It is this contact that indicates to the SPM that the motor has been started or stopped. Protection and synchro-nization routines will not run properly if this input is not connected.2. Ensure that all ground connections are made to the ground bus.Grounding to doors or other painted surfaces may cause the noise immunity of the SPM to be reduced.7.6.2 DON'Ts1. Don’t use the VDN module that was supplied with the old version MSPM (C0192) with the SPM.The VDN module has changed and is incompatible. Damage or miss operation will occur if used.2. Don’t use a 1A secondary CT with the SPMThe SPM has been designed to work with 5A CTs only.3. Don’t mount the SPM display remotely.The display must be mounted to the case when in operation. Noise problems may result if it is wired remotely.4. Do not enable the FIELD VOLTS setpoint if the exciter is not powered up prior to starting the motor.Field volts are monitored prior to starting and while the motor is running. A missing voltage start block will be is-sued if the SPM detects field volts less than the setpoint level while the motor is stopped and prevent startingof the motor.
