50 amp 125/250 twistlock ? bonding ?

[123weld]

I need to be able to run my single phase 230v welder and 110v grinders at a constuction site. Some makeshift telephone poles are bringing in 230v w/ some 6-4 cord with a female 50 amp 125/250 twistlock at its end.

I'm going to describe my unsure plan and theory on this.

My welder is 3 wires. I totally understand how to hook my two hot legs up. Now if I run the ground from welder to designated ground on receptacle and having no wire to connect to the nuetral wire on receptacle , welder should work fine as long as the ground is bonded to the nuetral in the panel or wherever this power is coming from. If it's not bonded, welder won't work because elecrticity can't return to complete it's loop. In this case I can switch the ground wire from welder to the nuetral on the female recptacle and complete the loop and welder should work. However I'm now a safety hazard because my welder hasn't a true ground. ????

It is also my understanding that all homes built in at least last 40 yrs have nuetral and ground bonded in panel. Someone told me that industrial buildings often aren't? ????

[denrep]

I need to be able to run my single phase 230v welder and 110v grinders at a constuction site...

...My welder is 3 wires....
...Now if I run the ground from welder to designated ground on receptacle and having no wire to connect to the nuetral wire on receptacle , welder should work fine as long as the ground is bonded to the nuetral ...

If your welder operates on 230v, the load should be connected from line to line, it will operate without a neutral connection. The third wire should be connected to ground, and normally would carry no current.

The connection to the neutral conductor would be used with a device that operates on 230v; yet also has some 115v circuits incorporated into it. The 230v load would be connected line to line; while 115v is derived from line to neutral. Of course the fourth wire would be ground, and is connected to the ground terminal.

I believe that the only exception, which is allowed to share ground and neutral on a 230v three conductor cord, is clothes dryer wiring.

The 110v grinder, of course, would connect line to neutral.

Be sure to confirm the voltage of that temporary drop.

Good Luck

[Sandy]

If your welder operates on 230v, the load should be connected from line to line, it will operate without a neutral connection. The third wire should be connected to ground, and normally would carry no current.

Ditto. Hook up your welder like your welder should be, hot-hot-ground. No switching of anything ever. When making up adapter cords wire up everything as per the NEMA/NEC wiring designations and the system will all work out fine.

[weldersales]

Keep in mind that the ground - green wire - serves only one purpose - to save your life. It is not used to carry current and in the case of a welder, 230 volt, you could cut the ground wire and the welder would not be affected. You would lose the safety feature but the operation of the machine would be unaffected. weldersales

[turboblown]

I assume what you are saying is that you will run a 230V welder from the two hot legs (240V) and the 120V grinder from one hot leg and the ground to make 120V.

This will work, provided the ground is connected to the true neutral at the other end of the supply. I've seen temporary services dedicated to 240V that has a ground that simply goes to a ground rod on the other end and not the true neutral.

You need to verify what is really on the other end. Another thing- watch out for OSHA! They'll cut your bean bag off if they catch you doing this on a job site!

[Sandy]

You need to verify what is really on the other end. Another thing- watch out for OSHA! They'll cut your bean bag off if they catch you doing this on a job site!

From the presentation it sounds like some one else brought this feed in (prime?).. Whoever brought the power in is the one who needs to worry about osha.

[Me!]

I assume what you are saying is that you will run a 230V welder from the two hot legs (240V) and the 120V grinder from one hot leg and the ground to make 120V.

To operate your grinder you use the one hot leg, and the NEUTRAL, not the ground. Using the ground will "work" but is dangerous to OTHERS using equipment on the same system.

And if OSHA compliance is an issue you also need a GFCI on your ex cords, and fused at max 20A