Input Power - Thermal Arc ARCMASTER 300 MST Operating Manual

2.05.02 Input Power

Each unit incorporates an INRUSH circuit and input voltage sensing circuit. When the MAIN SWITCH is
turned on, the inrush circuit provides a pre-charging of the input capacitors. SCR's in the Power Control
Assembly (PCA) will turn on after the input capacitors have charged to full operating voltage (after
approximately 5 seconds).
Note the available input power. Damage to the PCA could occur if 575VAC or higher is applied.
The following 208-230/460V Primary Current recommendations are required to obtain the maximum welding
current and duty cycle from this welding equipment:
Primary Supply
Model
8/4 AWG minimum
(Factory Fitted)
ARC
MASTER
300 MST
8/3 AWG minimum
Minimum Primary
Current Circuit Size
Lead Size
3
Phase
1
Phase
Table 2 – Primary Current Circuit Sizes to Achieve Maximum Current
Note 5
(Vin/Amps)
208/41
300A @
230/37
460/19
208/31
230/28
460/14
208/45
230/41
460/21
208/55
250A @
230/49
208/41
230/37
208/61
230/55
15
Current & Duty Cycle
MIG TIG
-
-
40%
-
-
300A @
-
40%
-
- -
- - 300A @ 40%
- -
-
40%
-
-
250A @
40%
-
- -
250A @ 40%
- -
STICK
-
-
-
-
-
-
-
-
-
-