TCI HG7 - Manual (Page 39)

P O W E R M O N I T O R P A C K A G E O N L Y
POWER MONITOR OPTION HG7 I, O, & M Manual 37
FAULT
Code
Troubleshooting Procedure
F11-F13
Fault
after
initial
normal
service
Filter Current Low Trip
If the F11, F12, or F13, fault occurred after the unit had been operating normally for some
time after initial startup (commissioning), use this procedure. If the fault occurred upon
initial startup (commissioning), refer to the previous section.
If the unit operated normally after setup and calibration, the fault usually indicates a fuse
cleared or a loss of capacitance occurred, thus lowering the normal current. Fault F11 is
associated with fuse Fu1(a), F12 is associated with fuse Fu1(a), and F13 is associated
with fuse Fu3(a). Check the fuses and replace any that have cleared with known good
fuses of the same type and rating. Check for signs of a short circuit.
Restart the filter and verify that the filter currents are at the proper levels. Caution!
Troubleshooting with the filter energized means there are hazardous voltages
present. Only qualified personnel should do this service work.
If the fuses are good, verify the integrity of the contactor. The electrical contacts are
consumable wear parts and may need service.
If the contactor is deemed in serviceable condition go to the Setup Procedure on page 32.
Step through the parameters and set parameter 11A to (1), exit the setup mode, and
allow the filter to reenergize in the Calibration Mode. Caution! When in the Calibration
Mode, the filter will not automatically disconnect upon recognizing a fault
condition. Measure currents; if lower than the percentage of nominal amount set in 7A,
an F11 fault will result. It is usually an indication of loss of capacitance. To locate the
faulty capacitor(s), first verify the proper line-to-line voltage is present at the terminals of
each capacitor. If the voltage is correct, then measure the current into each individual
capacitor. If any of the currents are lower than nameplate by greater than 10%, replace
the defective capacitor(s), and verify proper operation.
The factory default setting for the Filter Current Low Trip (parameter 7A) is 80% of the
filter’s nominal fundamental current rating the as determined by the filter’s kVar,
frequency, and voltage ratings (parameters 3A, 4a & 8A). If the trip level is set below
80%, the HG2 may not trip when a partial loss of capacitance has occurred. If the trip
level is set above 80%, the HG2 may trip unnecessarily. It is recommended that the
setting not be changed without consulting the technical support department at the
factory.
F21-23 Filter Over-current Fast Trip
The usual causes for this fault are:
Oversized drive for the capability of the filter.
Excessive harmonics present on the distribution system from other sources.
Partial loss of capacitance (thus causing the filter circuit tuning point to shift at or
above the designed frequency).
Line voltage is greater than 125% of the nominal rating.
Interaction with power factor capacitors on the distribution system resulting in system
resonance conditions.
If F21-F23 faults occur repeatedly in the apparent absence of any of the above problems,
verify the actual filter current with a current probe suited for true RMS measurements in a
harmonic rich circuit. Note: It may be necessary to inhibit the board from de-energizing
the filter by operating in the calibrate mode. However, be aware that if excessive currents
are indeed present, the technician must be able to rapidly remove power from the filter to
minimize damaging components or blowing the filter fuses.
The factory default setting for the Filter Over-current Fast Trip (parameter 5A) is 180% of
the filter’s nominal fundamental current rating as determined by the HG7’s kVar,
frequency, and voltage ratings (parameters 3A, 4a & 8A). If the trip level is set above
180%, the life of the capacitors may be reduced or the fuses may blow. If the trip level is
set below 180%, the filter may trip unnecessarily. It is recommended that the setting
not be changed without consulting the technical support department at the factory.