Hypertherm Powermax 30, Service Manual

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MAINTENANCE
powermax30
Service Manual 3-19
Test 5 – torch stuck open (TSO)
Before the torch’s trigger is pulled and gas starts to flow, the nozzle and electrode should be closed. If not, the
power supply will detect a TSO, or “torch stuck open,” fault. Use the following test to determine if the torch is stuck
open.
1. Set the ON/OFF switch to OFF (O).
2. Measure the resistance from the torch lead’s white wire group and red wire to the positive and negative
connections on the power supply. The resistance should read as closed.
3. If the resistance reads as open, then the nozzle and electrode are not touching, or one of the wires in the torch
lead is broken. Make sure that the torch plunger moves freely in the torch head. If it does not, replace the torch
head. If the torch parts are working properly, replace the torch lead.
White wire
group
Red wire