Lincoln Electric CITOTIG 315DC Service Manual page 58

INVERTER BOARD REMOVAL AND REPLACEMENT PROCEDURE
A
J11
B
REMOVAL PROCEDURE
Necessary tool:
- Screwdriver type PH02
- A small flat bladed screwdriver
- Torque wrench
1. Remove main input power to the CITOTIG 315DC or 415DC
2. Follow the case removal procedure available in this Service Manual
3. Perform the Discharge procedure
4. Disconnect the connector J11
5. Using the small flat bladed screwdriver remove the two thermostat wires from connector (A)
6. Using the screwdriver type PH02 remove the four (4) power harnesses screws (B)
7. Remove the potting protection and unscrew the 16 screws (C) that fix the board to the IGBT modules
8. Remove the potting protection and unscrew the 2 screws (D) that fix the board to the resistor R4
9. Unscrew the 4 screws in the corners of the inverter PCB (E)
10. Remove the inverter PCB from the machine.
11. If the IGBT modules need to be replaced remove the 2 screws that fix each of them to the inverter heat-
sink and replace them taking care to clean very well the heat-sink from the old thermal compound and
any dirty. To re-assembly correctly the new IGBT modules apply the thermal compound thin layer (0,1-
0,2 mm) under each ISOTOP component. Screw torque 1,2/1,4 N/m (0.030/0.033 N/inch)
12. For the Inverter Board re-assembly operations, make the previous steps in the reverse order and
add silicon to the zones where the potting protection was removed. ATTENTION ! : use silicon type with
low acetic, viscosity and adhesive grade.
PAY ATTENTION ! of how to position the open end mounting of
modules to heat-sink.
See printed circuit board for reference.
DISASSEMBLY OPERATIONS
C
B
C
D
59
ELECTRIC SHOCK
CAN KILL
E
E
DO NOT USE CORDLESS SCREWDRIVERS
FOR THE POWER MODULEs!
WARNING
Disconnect input power before servicing.
Do not operate with covers removed.
Do not touch electrically live parts.
Only qualified persons should install, use
or service this equipment.