104 Powermax125 Service Manual 808070
7 – Mechanized Cutting
Accessing raw arc voltage
To access divided raw arc voltage, refer to Field Service Bulletin 807060.
Connecting an optional RS-485 serial interface cable
The RS-485 serial interface connector on the back of the power supply allows you to connect an external device to your 
Powermax. For example, you can remotely operate the Powermax with a CNC controller.
The Powermax power supply must be equipped with a factory-installed (or user-installed) RS-485 serial interface 
connector on the rear panel. The receptacle on the rear of the power supply provides access to the RS-485 board inside 
the power supply.
If your power supply is not equipped with the RS-485 connector, order kit 228539, “Powermax65/85/105/125 RS-485 
board with cables”. Follow the installation instructions in the Power Supply Component Replacement section of the 
Powermax125 Service Manual (808070), which you can download from the Downloads Library at www.hypertherm.com
.
With the RS-485 connector installed:
1. Shut OFF the power supply.
2. Connect the RS-485 cable from your external device to the receptacle on the back of the Powermax power supply.
WARNING!
SHOCK HAZARD, ENERGY HAZARD, AND FIRE HAZARD
Connecting directly to the plasma circuit for access to raw arc voltage 
increases the risk of shock hazard, energy hazard, and fire hazard in the 
event of a single fault. The output voltage and the output current of the 
circuit are specified on the data plate.