GE SPM Series Instruction Manual

Also see for SPM: Instruction manual

Contents

GE SPM Series Instruction Manual Manual pdf 81 page image

GE Power Management SPM Synchronous Motor Protection & Control7-77 TESTING AND TROUBLESHOOTING 7.4 TROUBLESHOOTING7Motor starts andsynchronizes butshuts downimmediately uponapplication ofexcitation.TRIP PF setting too high. Reduce TRIP PF value (address 01) to no higher than –0.8.FCX DELAY setting too low. Increase FCX DELAY setting to 3 seconds minimum.Current/voltage inputs areincorrectly wired or are fromincorrect phases.Check and correct wiring as required.No excitation voltage. Check for available DC excitation voltage. If a rotating exciterdriven by a motor shaft is used, the exciter field should be forced(rheo is shorted out) during acceleration to cause exciter to buildup its output as quickly as possible.No excitation current, opencircuit at motor field, brushes,or leads.Correct discontinuity in field circuit.Wiring to terminal points ismissing or loose.Connect or tighten missing or loose wires to proper points on therear of the unit.Shutdown occursduring normalrunning (aftersuccessfulsynchronization)Motor has pulled out of stepfrom excessive overload (PFTRIP or PULL-OUT TRIP isdisplayed)Check condition of load bearing and other mechanical situationsat drives. Push any key to reset the SPM and restart.Loss of excitation Check exciter, exciter fuse, and connections to field.Transient power factor changeoccurring during system powerdisturbance.Increase PF DELAY setting.Motor is unloaded and powerfactor regulator referencesetpoint at or near unityresulting in instability.Increase REG FLOOR setpoint to override regulator to maintainstability during light-load condition.Wiring to terminal points onrear of unit missing or loose.Connect or tighten missing or loose wires to proper terminalpoints on rear of unit.Motor starts,applies DC tofield and thenimmediatelyremoves DC fromfieldExciter voltage too low causingSPM to attemptresynchronization.Adjust exciter transformer tap or exciter adjustment potentiometerto obtain higher exciter voltage output.Field contactor closing toosoon. Motor cannot pull-in tostep since slip too high.Reset SYNC SLIP to lower value.Excessive shaft load greaterthan the motor’s capability topull into step.Reduce load or unload motor during start. Apply load after motorhas synchronized and stabilized.Wiring to terminal points onrear of unit missing or loose.Connect or tighten missing or loose wires to proper terminalpoints on rear of unit.Display frozen,garbled, incorrect,or unreadableLoose electrical connections orCPU failure.Momentarily interrupt control power to unit and then re-energize. Ifstill displaying incorrectly, replace unit OR check ribbon connectorbetween faceplate assemble and top of cradle. It must not beloose, shifted, or skewed.Contrast needs adjustment. Open lower flip door on faceplate assembly and rotate thecontrast adjustment to obtain clear display.Table 7–1: SPM TROUBLESHOOTING (Sheet 2 of 2)SYMPTOM POSSIBLE CAUSE CORRECTIVE ACTION