Hypertherm HPR260 Manual Gas Preventive Maintenance Program Rev.5 - Manual (Page 184)

MAINTENANCE
5-40 HPR260 Auto Gas Instruction Manual
Start circuit functional schematic
Start circuit troubleshooting
DANGER
SHOCK HAZARD: Always use caution when servicing a power supply when plugged in and the
covers are removed. Dangerous voltages exist within the power supply which could cause injury or
death.
Start-circuit PCB1
Operation
The start circuit is a high-speed switch that quickly transfers the pilot arc current from the pilot arc lead to the work lead.
The start circuit performs 2 functions:
1. It allows the initial pilot arc current to flow through the pilot arc lead quickly, with little impedance.
2. After initial pilot arc current is established, the start circuit introduces impedance to the pilot arc lead to aid in
transferring the arc to the workpiece. See schematic below.
5