Service Manual
Test Procedures
7 - 18
3x3 UPS
Issue 2 - November 2001
7.
Disconnect the cables attached to current transformer TA1 TA2 and TA3 IGBT connection
extension pillars and lift off the CT's.
Note: An inĆsitu test for a short circuit IGBT can be carried out at this point
before the devices are removed.
8.
Disconnect the gate drive fastĆon connectors from the IGBT's and note their position for
reĆassembly.
9.
Remove the four retaining IGBT securing Allen screws from each IGBT and remove each
IGBT.
10. Test each IGBT for serviceability follow the IGBT test procedure on
page 7Ć20
.
11. Replace any components found defective.
IGBT fitting is the reverse of the removal procedure refer to
Table 7-6
for correct IGBT gate drive conĆ
nector location.
Table 7-6
Inverter IGBT Gate Drive Connectors
IGBT Gate Lead Terminal
IGBT
Connector
4
5
7
6
Q1
J11
Red
Black
Black
Red
Q2
J9
Blue
Black
Black
Blue
Q3
J11
Red
Black
Black
Red
Converter IGBT (Q4) Removal
1.
Power down the UPS and carry out the DC bus discharge routine.
2.
Gain access to the UPS power section by removing the top and side covers.
3.
Disconnect and remove the Inverter driver/feedback PCB Part NºOSDE0071. Follow the
procedure on
page 7Ć32
.
4.
Remove the converter bus bar retaining screws from IGBT Terminal 2 and 4.
5.
Remove capacitors C9 and C10 from the bus bars.
6.
Remover the connecting screws from diodes CD4 and CD5
7.
Remove the bus bar retaining screws from the insulated pillar.
8.
Slacken the converter current transformer (TA4) mounting bolt securing the CT and bus bar,
and reposition to gain access to Q4.
Note: An inĆsitu test for a short circuit IGBT can be carried out at this point
before the devices are removed.
9.
Disconnect the gate drive fastĆon connectors from the IGBT and note their position for
reĆassembly.
10. Remove the four retaining IGBT securing Allen screws and remove from IGBT from the
heatsink.
11. Carry out a test of the IGBT for serviceability follow the IGBT test procedure on
page 7Ć20
.
12. Replace IGBT if found defective.
IGBT fitting is the reverse of the removal procedure refer to
Table 7-7
for correct IGBT gate drive conĆ
nector location.
Table 7-7
Converter IGBT Gate Drive Connectors
IGBT Gate Lead Terminal
IGBT
3
5
Q4
Red
Black