Hypertherm Powermax30 Service Manual - Manual (Page 75)

MAINTENANCE
3-36
powermax30
Service Manual
13. Stand up the unit again. Tuck out of the way all the wires that you detached.
14. Pull the board straight out from the power supply.
15. Before installing a new power board, clean the heatsink with isopropyl alcohol. Gently scrub away any residual
thermal compound, being careful not to scratch the heatsink. Wipe it with a clean cloth.
16. Spread a thin layer of thermal compound 2 mil thick (about the thickness of a sheet of paper) on all the IGBTs.
17. Spread a layer of thermal compound 2 mil thick on the snubber resistor, starting from the bottom and dragging
toward the top (away from the prongs). It is important to avoid getting any compound on the prongs.
18. Push the red and white wires that are attached to the new power board through from the power board side of
the power supply to the fan side of the power supply.
19. Line up the capacitors on the back of the power board with the holes in the power supply’s center panel.
20. Push the power board straight in.
21. Reconnect the 2 white wires to the ON/OFF switch
22. Replace the 4 heatsink assembly screws and the 3 retaining screws. Torque these screws to 15 inch-pounds
(17.28 kg cm).
23. Replace the screw you removed from the snubber resistor in step 10. Torque it to 7 inch-pounds (8.06 kg cm).
Note: Torque settings greater than 7 inch-pounds (8.06 kg cm) may damage the resistor.
24. Replace the 5 screws that attach the IGBTs to the heatsink. The torque setting for these is 15 inch-pounds
(17.28 kg cm).
25. Reconnect the wires to the transformers and inductors at J13, J14, J15, J18, J19, J20, and J21 and the work
lead ring terminal at J22. Torque them to 20 inch-pounds (23.04 kg cm).
26. Replace the torch start and cap sensor connector at J12 and the connectors at J4, J5, and J6.
27. Reconnect the ribbon cable from the control board to the power board.
28. Attach the red and white wires to the studs on the fan side of the board.
29. Being careful not to pinch any of the wires, replace the Nomex barrier and slide the cover back onto the power
supply. Make sure that the bottom edges are in the tracks. Position the handle over the holes in the top of the
cover, then use the 2 screws to secure the cover.
30. Reconnect the electrical power and the gas supply.