Hypertherm Powermax105 Service Manual - Manual (Page 147)

TroubleshooTing and sysTem TesTs
powermax
105 Service Manual 8-9
External inspection
1. Inspect the exterior of the power supply for damage to the cover and external components, such as the power cord
and plug.
2. Inspect the torch and the torch lead for damage.
3. Inspect the consumables for damage or wear.
Internal inspection
1. Turn OFF the power, disconnect the power cord, and disconnect the gas supply.
2. Using a TORX or blade screwdriver, remove the screws from the power supply cover.
3. Lift the cover off the power supply.
4. Remove the Component barrier from the power board side of the power supply. This barrier is flexible and can be
bent slightly for removal. Be certain to replace the barrier when you are finished working on the power supply.
5. Inspect the inside of the power supply, especially on the side with the power board. Look for broken or loose wiring
connections, burn and char marks, damaged components, and so on. Repair or replace as necessary.
Initial resistance check
All resistance values must be taken with the power cord disconnected and all internal power supply wires attached.
Perform the steps in Internal inspection before continuing in this section.
• If resistance values are not close (±25%) to the values given in this section, isolate the problem by removing
wires attached to the resistance check points or component until the problem is found.
• After the problem has been located and repaired, refer to the Sequence of operation flow diagram in this
section to test the power supply for proper operation.
Check the power switch
Refer to the figures and table on the following pages.
1. With the power disconnected and the torch removed from the power supply, set the ON/OFF switch (S1) to ON (I).
2. Check the resistance across the input leads (the leads are labeled L1, L2, and L3 on the power switch).
- 200-600 V CSA: resistance across the input leads = 500 kΩ.
- 230-400 V CE, 380 V CCC/230-400 V CE, 400 V CE, 380 V CCC: resistance across the input leads =
350 kΩ.
3. Check the resistance from the input leads to ground to verify that it reads as open. For all power supplies, the
resistance from input to ground should read as > 20 MΩ.
Note: With the power disconnected and the ON/OFF switch (S1) set to OFF (O), all circuits should read
as open.
The electrical values shown are ±25%.
4. Check the output resistance for the values shown in the table.