104
PRELIMINARY
5.2 Troubleshooting Flow Charts (continued)
5.2.6 “BYPASS STATIC SWITCH FAULT”
5.2.7 “BYPASS STATIC SWITCH OVERLOAD”
5 Troubleshooting (continued)
Start
Are the
bypass SCRs
functioning?
(1)
Replace the SCR
Replace the M board
(2)
N
Y
END
Does the
fault still occur w/ UPS
in bypass mode?
Replace the S or SA board
(3)
Y
N
Fig 5.2.6a
Fig 5.2.7a
Note (1): Use a multimeter to measure the pins of bypass SCRs. If the ohm value is close to zero, it indicates that the SCR has failed. (For the
location of bypass SCRs, turn to section 1.5)
Note (2): For the location of the NHS-SYS-M board, turn to section 1.5. To replace the NHS-SYS-M board, remove the EEPROM chip from the old
NHS-SYS-M board and insert it into the new one.
Note (3): For the location of the NHS-SYS-S board (for 60kVA and 80kVA) or the NHS-SYS-SA board (for 20kVA and 40kVA), turn to section 1.5.
Note (1): Use a multimeter to measure OIP CT resistance. If the value is about 35ohm, the OIP CT is good.
Note (2): To learn about EEPROM parameter settings and calibration, turn to section 3.2.
Note (3): To learn the location of the NHS-SYS-P and NHS-SYS-M boards, turn to section 1.5. To replace the NHS-SYS-M board, remove the
EEPROM chip from the old NHS-SYS-M board and insert it into the new one.
Start
Is the UPS loading
too high?
Reduce loading
Is the load CT
functioning?
(1)
Calibrate parameter on
EEPROM
(2)
Replace P board or M
board
(3)
Replace CT
END
N
YY
N
