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iGUARD Troubleshooting
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Generator Section
IMPORTANT
CAUTION NOTICE
- Problems with AC voltage
- Problems with AC current
- Problems with AC power (kW or kVA)
- Problems with AC frequency
- Problems with power factor
Troubleshooting AC Parameters
CAUTION: LETHAL VOLTAGES AND CURRENTS MAY BE PRESENT!!!
All due caution should be exercised when investigating AC voltage and current connections. Live AC may - and should always be assumed to be - present. If you are not totally familiar and conversant with the necessary precautions and safety practices relevant to troubleshooting this type of equipment, call a licensed electrician! Voltages and currents may be present and should be assumed to be at a lethal potential at all times.
The most common - by at least a factor of 20 - cause of problems associated with any of the AC parameters not reading, reading wrong, reading erratically, or causing nonsense information to be displayed, is caused by the AC connections not being made correctly. It is easy to get wrong, but it's also easy to fix!
The following text descriptions are also accompanied with some 'common' setups diagrams to help explain and or clarify the details, as well as make installing and applying the iGUARD easier.
Problems with AC Voltage - Be aware that a shutdown for excessive loading, improperly adjusted governor, or automatic voltage regulator problems (AVR) may give a message to the effect of over/under voltage as the set hunts for its proper operating point.
1. No voltage displayed
a. Alternator putting out AC voltage?
b. Check the wire connections from the energy monitoring board to the AC source.
c. Verify that AC voltage is reaching the plug
d. Check that the plug is seated in the energy monitor board
e. Is AC neutral connected?
f. Contact FWM tech services
2. Shuts down on under or over voltage at startup
a. AC voltage present?
b. Measure actual voltage
c. Below/above setpoints?
d. Adjust AC voltage (AVR) or adjust O/U voltage setpoint
e. Verify that AC neutral is connected to system and is properly bonded to earth and or generator frame as necessary
3. Shuts down on over/undervoltage after running for awhile
a. AC voltage present?
b. Measure actual voltage
c. Below/above setpoints?
d. Adjust AC voltage (AVR) or adjust O/U voltage setpoint
e. Is set being block loaded or unloaded?
f. Verify that the generator set is recovering within the programmed warning timer (one of the last three selections in the AC setup on the iGUARD).
g. Verify that the AVR is recovering
4. Voltage reading is wrong
a. Set for L-L or L-N readings as desired?
b. AC Neutral in plug and properly bonded to earth?
c. Calibrate iGUARD voltage reading (see IOM)
NEVER UNPLUG THE CURRENT TRANSFORMERS UNDER LOAD. THIS IS POTENTIALLY LETHAL AND MAY RESULT IN INJURY OR DEATH TO PERSONNEL OR THE DESTRUCTION OF THE CURRENT TRANSFORMERS
1. No current displayed
a. Alternator putting out AC voltage/current?
b. Check the wire connections from the energy monitoring board to the current transformer(s).
c. Verify that AC current is reaching the plug - Check that the plug is seated in the energy monitor board
d. Is there actual current demand / load?
2. Shuts down on overcurrent at start up
a. Adjust instantaneous overcurrent setpoint
b. Is generator undersized for load?
3. Shuts down on overcurrent after running for awhile
a. Is the overcurrent setting lower than the actual operating current?
b. Is the load relatively steady or are there large swings?
i. If the load is relatively steady overcurrent shutdowns can come from either reaching the instantaneous shutdown point (The max current setting) or by running at greater than full load longer than the IDMT constant.
ii. If there are large swings - rapid block loads and unloads - you may need to increase either the overcurrent setpoint or the bubble timer associated with overcurrent events.
c. Is the CT ratio correct?
4. Reverse current indicated
a. Swap (+) and (-) leads on all CT's in system
5. Reverse current indicated on only one or two phases
a. Physically verify that AC Volts L1 is connected to L1
b. Physically verify that AC Volts L2 is connected to L2
c. Physically verify that AC Volts L3 is connected to L3
d. Physically verify that AC current CT for L1 is on L1
e. Physically verify that AC current CT for L2 is on L2
f. Physically verify that AC current CT for L3 is on L3
g. Physically verify that all CT's are oriented the same way
6. Current reading is wrong
a. Is the reading approximately ½ of correct? Verify how the CT is connected to the system. If both the CT leads from each CT are brought back, change CT to Grounded = NO
b. Is the reading approximately double correct? Verify how the CT is connected to the system. If only one of the CT leads from each CT is brought back to the iGUARD , change CT to Grounded = YES
c. Verify that the voltage and current connections are correct:
i. Physically verify that AC Volts L1 is connected to L1
ii. Physically verify that AC Volts L2 is connected to L2
iii. Physically verify that AC Volts L3 is connected to L3
iv. Physically verify that AC current CT for L1 is on L1
v. Physically verify that AC current CT for L2 is on L2
vi. Physically verify that AC current CT for L3 is on L3
vii. Physically verify that all CT's are oriented the same way
d. Calibrate AC current (See IOM)
Problems with AC Power (kW or kVA)
1. No power displayed
a. Verify that the CT's are connected
b. Verify that the CT's are the proper range (1000:5 vs 100:5 makes a huge difference!)
c. Is there a load with current flow in the system?
d. Is power factor showing PFC2 or PFC3? Load current may be below threshold. Increase load (if possible) to test
e. Is the PF showing PFC1 or PFC3? If so the load current may be changing >10% per measurement, and the iGUARD is forcing the PF to 1.00 until the data settles out.
2. Shows wrong value
a. Verify that the voltage and current connections are correct:
i. Physically verify that AC Volts L1 is connected to L1
ii. Physically verify that AC Volts L2 is connected to L2
iii. Physically verify that AC Volts L3 is connected to L3
iv. Physically verify that AC current CT for L1 is on L1
v. Physically verify that AC current CT for L2 is on L2
vi. Physically verify that AC current CT for L3 is on L3
vii. Physically verify that all CT's are oriented the same way
b. Is the PF showing PFC1 or PFC2? If so the load current may be changing >10% per measurement, and the iGUARD is forcing the PF to 1.00 until the data settles out.
1. Over/under frequency warnings or shutdowns
a. Is AC voltage present? (No voltage = no frequency)
b. Check AC frequency at no load. Should be very close or equal to nominal
c. Check AC frequency during load. Should be > under frequency setpoint and < over frequency setpoint
d. Is governor recovering too slowly?
e. Is genset too small for load?
f. Is load noisy?
2. Incorrect frequency readings
a. Measure AC frequency & verify
b. Is load noisy?
c. Check AC neutral for proper bonding to earth
1. Inaccurate power factor
a. Verify that the voltage and current connections are correct:
i. Physically verify that AC Volts L1 is connected to L1
ii. Physically verify that AC Volts L2 is connected to L2
iii. Physically verify that AC Volts L3 is connected to L3
iv. Physically verify that AC current CT for L1 is on L1
v. Physically verify that AC current CT for L2 is on L2
vi. Physically verify that AC current CT for L3 is on L3
vii. Physically verify that all CT's are oriented the same way
2. Shuts down on power factor
a. Adjust power factor limit to 0% and run under load.
i. Is displayed PF reasonable under load?
ii. If PF is strange or unreasonable, it is virtually certain that the AC voltage and/or current is not connected in proper sequence. See 1.a above
b. Adjust PF limit to meet actual operating conditions
c. Is PF unstable or greatly in error? Verify that the voltage and current connections are correct:
i. Physically verify that AC Volts L1 is connected to L1
ii. Physically verify that AC Volts L2 is connected to L2
iii. Physically verify that AC Volts L3 is connected to L3
iv. Physically verify that AC current CT for L1 is on L1
v. Physically verify that AC current CT for L2 is on L2
vi. Physically verify that AC current CT for L3 is on L3
vii. Physically verify that all CT's are oriented the same way
3. PFC1 warning
a. Power factor is being forced to 1.00 because the measured value is changing more than 10% in 6 seconds
b. If it does not clear in less than ~20 seconds see 1.a above
4. PFC2 warning
a. Power factor is being forced to 1.00 because the measured AC current is too low to accurately calculate power factor reliably.
b. As long as the load current is too low this warning will stay active. But increasing the load current to > 5% (approximately) of the full scale CT ratio should clear this error in a few seconds
5. PFC3 warning - Combination of both PFC1 & PFC2
a. Power factor is being forced to 1.00 because the measured value is changing more than 10% in 6 seconds AND the measured AC current is too low to accurately calculate power factor reliably.
b. If this doesn't resolve itself into either a PFC1 or PFC2 within a few seconds, see 1.a above
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