- On the Static switch control board the dip switches should be set as follows: SW1 - 120 position closed (on) all others open, SW2 - positions 1 to 4 closed and position 5, open for 120 or 240, closed for 208.
- In order for a transfer to occur, the Inverter and bypass must be "IN SYNC" (less than 25V difference voltage), the inverter voltage must be within 90% (95%) of nominal, the system output must not be overloaded and the battery breaker must be closed. The front panel "IN SYNC" LED must be on and when provided the "Inverter Failure", "System Overload", and "Battery Breaker Open" LED’s must be off. On the static switch board the same conditions are shown as follows:
- TP4 continuously high (11.5 to 12V) indicates an "IN SYNC" condition.
- TP5 continuously high (11.5 to 12V) indicates an "Inverter Normal" condition.
- TP1 continuously high (11.5 to 12V) indicates a "System load normal" condition.
- TP6 continuously high (11.5 to 12V) indicates a "Bypass available" condition.
CHECK: Check inverter output Voltages, check output current.
SOLUTION or EXPLANATION: If the inverter output is low, see the appropriate Inverter failure above. If the current on any one phase is too high, correct the problem at the load. If the inverter output voltage is normal and IN SYNC, check J4 and reconnect. Then on the Static Switch Control board, measure from the board ground test point to TP1, TP5 and to board +12V. If +12V is not available or low replace the board. If TP4 is not above 11.5V, the static switch board is detecting an over current on the output. If no over current is present, replace the board or check for high crest factor loads. If TB5 is not high, the board is detecting an inverter under voltage. If the inverter voltage is normal, adjust potentiometers R53, R120, and R121 one at a time. Adjust only one turn in each direction. If this has no effect on TP5, return the potentiometer to the original position and adjust the next potentiometer. If this fails to correct the problem, replace the Static Switch board.
CHECK: Check static switch board TP6 if low check the bypass voltages. Check the wires and connector J11 on the motherboard. Check the items in previous problem.
SOLUTION or EXPLANATION: Reconnect J11. Correct the bypass up stream from the UPS. On the Static Switch Control board, measure from the board ground test point to TP6. If TB6 is not above 11V, the static switch board will detect a bypass failure. If the bypass is available and the normal voltage is present, replace the board.
CHECK: The Voltage between the inverter (SCR11) wire #46 and bypass wire #40, and inverter (SCR15) wire #54 and bypass wire #48.
SOLUTION or EXPLANATION: If the voltage is less than 25VAC and constant between 40 and 46 and between 48 and 54, the unit is IN SYNC. On the Static switch board, check TP4 with the unit in sync, TP4 should be 11VDC or higher. Replace the Static switch board if not. If voltage is greater than 25VAC and/or changes high than low, the Inverter is not coming into sync or the inverter output is connected to the bypass. Replace the inverter board. If that fails to fix the problem, then check the static switch gate boards and SCR's 10 to 17.
CHECK: Before replacing fuses or closing breaker, check the Static Switch SCR's (10-13,14-17,18-21) for a shorted device. Check the small static switch gate boards for damaged components.
SOLUTION or EXPLANATION: Replace the Shorted SCR and replace the gate board associated with the fuse that is blowing. Once in a while, a static switch SCR will partially fail and the bad device cannot be located. Therefore, if no shorted device is found and the gate board does not help, replace all the SCR's in the leg that is blowing the fuse or breaker.