GE SPM Series, Instruction Manual

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GE Power Management SPM Synchronous Motor Protection & Control 7-
13
7 TESTING AND TROUBLESHOOTING 7.7 FREQUENTLY ASKED QUESTIONS
7
7.7 FREQUENTLY ASKED QUESTIONS 7.7.1 SPM FAQ
1. Is the SPM a drop in replacement for the
µ
SPM?
Functionally the SPM is a replacement for the older
µ
SPM. The following points detail the differences between
the SPM and the
µ
SPM when retrofitting:
• The SPM cutout size smaller. An MPSPM retrofit panel can be ordered to retrofit the SPM into existing
µ
SPM cutouts.
• Terminal numbers have changed but terminal labels and functions remain the same.
• The VDN module has changed and the SPM must be used with the new VDN supplied with it. The CM and
DCCT are the same and can be used with the SPM or
µ
SPM.
• All
µ
SPM options except for PF Regulation (which can be ordered) are standard on the SPM.
2. What do I do if I forget my password?
If a non-0000 password has been entered for access to programming it must be entered to gain write access.
If this password has been forgotten it may be recovered in the following manner:
1. Using the GE key go to the programming section.
2. Press the scroll up key.
3. When asked to enter the password, press and hold the scroll up key and then without releasing press
and hold the enter key. While both keys are held and encrypted password will appear on the screen.
4. Record this password and contact the GE Power Management service center. They can decode the
password for you.
3. What causes a run time fault?
A run time fault is initiated by the SPM when it calculates a metered value beyond its acceptable range. The
two most common causes of this are:
• SPM measures a starting current higher than the programmed locked rotor current.
Solution: program LR AMPS with maximum current value seen during a start.
• SPM measures the field ohms to be beyond range of DCCT.
Solution: Turn the HIGH FIELD setpoint OFF and check calibration of DCCT and CM.
4. What is the cause of an incomplete sequence trip and how do I correct it?
An incomplete sequence trip is issued if the motor fails to synchronize in a set amount of time. Check the fol-
lowing points:
• Has the
INC SEQ DLY
been set long enough to allow the motor to start?
• Check the VDN wiring VDN. Is it properly connected across the field discharge resistor (ring type motors)?
• Has the
SYNC SLIP
setting been set to the correct level (ring type motors)?
• Measure the frequency at the V
F
+/– terminals and ensure it falls below the programmed slip level. If not,
check wiring, grounding, and the motor.
5. What is the SPM internal CT burden?
The CT burden is 16 m
Ω
or 0.4 VA at 1
×
CT.
6. What is the power consumption to the SPM?
The SPM draws 10 VA nominal at 120 V AC.