A brief intro of this application history.
Information provided, this application was working fine and we had many more welders running so what’s the problem now.
Issues:
Fuses blowing, breakers tripping & failing, melting plugs, receptacles, extension cord connectors and wiring at disconnects.
Cause:
Someone just didn’t do it right, could be just like a loose wire.
Request:
Add more welder receptacles also fix plugs, receptacles and extension cords.
Observation:
Stress from the magnitude of welders running on the same overamped circuits. With two and three welders running on the same disconnects with oversized fuses, and so many running at the same time. Possibility of an unbalanced load on one phase at the panels causing failure to one leg on 3-pole breakers. Exceeding the load on the panel, transformer and only a primary breaker.
Suggested Solution:
Wiring from the 240v panel to the disconnects needs to be tested for faults
Removal of the delta xmfr and install a smaller wye to provide necessary 230v single phase for only three welders all other welders are a dual voltage. Install 480V 3Ph MLO panelboard adjacent to location of welders.
All of the manufacture’s manuals show individual disconnect adjacent to the welders. Art. 630 also indicates disconnection means for each welder. Plan to install the 480 panel within 50’ of all welders and add safety switches to comply with 630.13.
Thank you all for the support