GE SPM Series Instruction Manual

Also see for SPM: Instruction manual

Contents

7- 2SPM Synchronous Motor Protection & Control GE Power Management7.1 START-UP PROCEDURE 7 TESTING AND TROUBLESHOOTING7• Squirrel Cage Protection Test (SC PROT TEST): An internal SCP test frequency is inserted into theSCP program. After a time delay corresponding to the STALL TIME setpoint, the display reads SQLCAGE TRIP!. Press any key to reset.• Synchronization and Power Factor Test (SYNC AND PF TEST): An internal slip frequency is injectedinto the synchronizing circuitry and slowly glides downward (simulating an accelerating motor).When this frequency matches the SYNC SLIP setpoint, the display flashes FIELD IS APPLIED and theFAR relay picks up, followed by the FCX after the FCX DELAY time setpoint. Next, the SPM automat-ically tests the power factor circuitry by internally generating a test power factor signal. No operatorinterface is required to proceed from the synchronizing test to the power factor test. This signalslowly decreases until it dips below the PF TRIP setpoint. After the PF DELAY setpoint time, the dis-play reads PWR FACTOR TRIP!. Press any key to reset the unit. If SPM is in the RESYNC mode, theSPM may attempt to re-synchronize. If it does, the FIELD IS APPLIED message is displayed momen-tarily before a power factor trip occurs.5. To leave TEST MODE, press and release the GE key until SPM READY is displayed again.BE SURE TO STOP THE MOTOR AND DE-ENERGIZE ALL POWER BEFORE CHANGING ANYLEADS.7.1.3 START-UP DESCRIPTIONClosing the feeder to the controller unit provides power to the control circuits and to the SPM. Energizing theSPM causes the TRIP relay contacts (terminals TRP1–TRP2) to close and the SPM to display SPM READY.Refer to Figure 2–4: PANEL AND TERMINAL LAYOUT on page 2–5 for trip relay contact locations and Figure2–3: TYPICAL WIRING DIAGRAM on page 2–4 for wiring details.Pressing the START button picks up relay MX, which in turn energizes the coil of main contactor M. When Mcloses and applies AC power to the motor, induced field current flows through the field discharge resistor andan associated voltage drop appears across terminals VF + and VF –. The frequency of this induced field volt-age decreases as the motor speed increases, and the speed sensing circuits of the SPM cause the FAR relayto close as the motor reaches the programmed slip value. When the FAR relay contacts (terminals FAR1–FAR2) close, the field contactor (FC) closes and applies excitation to the motor from the exciter.After the programmed FCX DELAY, the FCX relay picks up and closes its contacts, allowing the customer's auto-matic loading circuits to be activated.WARNING