ARCMASTER 401S POWER SOURCE
INSTALLATION, OPERATION AND SETUP
3-2
Manual 0-5345
WARNING
ELECTRIC SHOCK can kill; SIGNIFICANT DC VOLTAGE is present after removal of input power.
DO NOT TOUCH live electrical parts.
SHUT DOWN welding power source, disconnect input power employing lockout/tagging procedures. Lockout/
tagging procedures consist of padlocking line disconnect switch in open position, removing fuses from fuse box,
or shutting off and red-tagging circuit breaker or other disconnecting device.
Electrical Input Requirements
Operate the welding power source from a single or three-phase 50/60 Hz, AC power supply. The input voltage
must match one of the electrical input voltages shown on the input data label on the unit nameplate. Contact the
local electric utility for information about the type of electrical service available, how proper connections should
be made, and inspection required. The line disconnect switch provides a safe and convenient means to completely
remove all electrical power from the welding power supply whenever necessary to inspect or service the unit.
NOTE
This unit is equipped with a three-conductor with earth power cable that is connected at the welding
power source end for single or three-phase electrical input power.
Do not connect an input (WHITE, BLACK or RED) conductor to the ground terminal.
Do not connect the ground (GREEN) conductor to an input line terminal.
Refer to Figure 3-1 and:
1. Connect end of ground (GREEN) conductor to a suitable ground. Use a grounding method that complies
with all applicable electrical codes.
2. For 3- phase operation, connect ends of line 1 (BLACK) and line 2 (WHITE) and line 3 (RED) input conductors
to a de-energized line disconnect switch.
For 1- phase operation, connect BLACK and WHITE input conductors. Insulate the RED Conductor.
3. Use Table 3-1 as a guide to select line fuses for the disconnect switch.
Fuse Size
Input Voltage
1 Phase
3 Phase
208 VAC
100 Amps
60 Amps
230 VAC
80 Amps
50 Amps
460 VAC
50 Amps
30 Amps
Table 3-1 Electrical Input Connections
NOTE
Fuse size is based on not more than 200 percent of the rated input amperage of the welding power
source (Based on Article 630, National Electrical Code).
