Tweco 300 MST Arcmaster User Manual

Page 21

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 5

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:

Current & Duty Cycle

Model

Primary Supply

Lead Size

Minimum Primary

Current Circuit Size

(Vin/Amps)

MIG TIG STICK

208/41

- -

230/37

- -

460/19

300A @

40%

208/31

- -

230/28

- -

460/14

300A @

40%

208/45

- -

230/41

- -

8/4 AWG minimum

(Factory Fitted)

Phase

460/21

- -

300A @ 40%

208/55

- -

230/49

250A @

40%

208/41

- -

230/37 -

250A @

40%

208/61

- -

ARC

MASTER

300 MST

8/3 AWG minimum

Phase

230/55 - -

250A @ 40%

Table 2 – Primary Current Circuit Sizes to Achieve Maximum Current