Hypertherm Powermax105 Service Manual - Manual (Page 191)

TroubleshooTing and sysTem TesTs
powermax
105 Service Manual 8-53
Install a test
jumper here
J27
WORK
LEAD
J26
RED
J18
ORG
J17
J32
J28
RED
Before continuing, turn OFF the power.
If the resistance value is always less than 100 Ω, remove the torch and recheck the resistance. If the value is still less
than 100 Ω:
• Use an IGBT tester to check for a shorted pilot arc IGBT.
• Replace the pilot arc IGBT if it is shorted.
If the resistance is always greater than 100 Ω:
• Replace all consumables and recheck.
• If the resistance is correct (<100 Ω) the old consumables are bad.
• If the resistance is still greater than 100 Ω, measure the resistance in the torch between the pilot arc wires (Pin
1 or 2) and negative arc power (the center connection).
• If the resistance is still too high, replace the torch and lead.
Note: The retaining cap should be snug but not over-tightened.
All values are ±15%
Check the function of the pilot arc IGBT:
• Turn the machine off and disconnect power.
• Install a jumper wire (at least 8 AWG) from the work lead (J27) to the pilot arc IGBT (dual black wires).
• Reconnect power and turn on the machine.
• Attempt to fire the torch.
• If the torch fires, replace the pilot arc IGBT.