240 volt grinder with 120 volt work light!

[Bill Z]

Greetings,
I'm in the process of wiring my new 24 by 34 foot detached garage. I installed a 100 amp sub panel and dedicated straight 240 volt circuits for my welder, drill press and compressor. My question is about an older Sears 8" 1 HP 115/230 volt pedestal grinder that I'm also running a dedicated 240 volt circuit for.

It's wiring is currently configured for 240 volt use, which I will keep, but it has a built in 120 volt adjustable work light. I'm assuming that it's using the ground wire of it's three blade plug for the neutral part of the light circuit. Is that even allowed now, considering that my sub panels neutral bar is isolated and the ground bar is bonded to it's case?

 

[sberry]

No, it cant use 3 wire. I personally would wire it back 120 and use it on a general circuit. While its tempting to want to run it on higher voltage its so much more practical to save equipment, use a common circuit. Not sure why a guy would want a dedicated for it unless he absolutely had to.

 

[prostreetamx]

They still make appliances today that bond the neutral and ground to the chassis even though code requires you to use a 4 conductor cord and plug even though there normally is only 3 connection points. If there is a neutral available in the box and you are concerned about it, you can just replace the cord and wall plug with 4 prong stuff. I put a neutral in every 240v box in my new garage, just in case. Even though the neutral and ground are separate in the sub panel, they are bonded together at the main. You are not supposed to use a ground as a current carrying conductor but some guys do it anyway.

 

[pattenp]

Why not just buy a 240V light bulb.

 

[yeldogt]

I have two 1hp grinders/ polishers -- both run fine on 110. I have seen large Baldor grinders where the light has a separate plug ... my guess is if Sears supplied for 220v with only one plug they figured a 220v bulb.

Our old factory in Wilmington was all 220v lighting .. real pain.

 

[sberry]

I got a lot of stuff. I have a neighbor has a common garage and he has basically 2 and on occasion a 3rd 240 circuit. But generally air comp and a welding outet at 240 and if its humanly possible the rest of it gets 120. Wire a garage similar to kitchens and kitchen counter tops.
Like a microwave I got no problem running another wire to a fixed piece or once I know the load. MY shop is big so there are some other issues but my neighbor runs about 20 tools from 2 circuits, 1 for fixed stuff like a mill and lathe and some saws from a ceiling cord for stuff he moves to the middle for handling, table saw, chop saw.
You don't need multiple quad boxes with multiple circuits but a tool circuit on each wall with an outdoor is good and a general or 2 in convenience areas, somewhere a guy can hook a power strip to, plug in a light and a clock.

 

[sberry]

I got a big Baldor but it isn't even installed. I got 1 little 6 inch pos with a wire wheel and a crude grinder stone and I cant even remember when I used the stone. I have a dozen air tools with specialty stuff, about 1/2 a dozen I use regular and a couple 4 1/2 electrics.
Same for a drill press, I am so used to and have come up with methods to do it handheld that is what I do.

 

[exmaxima1]

No, it cant use 3 wire. I personally would wire it back 120 and use it on a general circuit. While its tempting to want to run it on higher voltage its so much more practical to save equipment, use a common circuit. Not sure why a guy would want a dedicated for it unless he absolutely had to.

+1
Assuming it's a CM block grinder, it draws less than 7 amps at 120v so not an issue in the least.

 

[wyliesdiesels]

They still make appliances today that bond the neutral and ground to the chassis even though code requires you to use a 4 conductor cord and plug even though there normally is only 3 connection points. If there is a neutral available in the box and you are concerned about it, you can just replace the cord and wall plug with 4 prong stuff. I put a neutral in every 240v box in my new garage, just in case. Even though the neutral and ground are separate in the sub panel, they are bonded together at the main. You are not supposed to use a ground as a current carrying conductor but some guys do it anyway.

That only applies to existing grandfather range and dryer circuits.

If there is a 4-wire range or dryer outlet, then the appliance needs to be converted to 4-wire...

NEVER run neutral current on a grounding conductor. U can kill someone doing that...

 

[Ditch]

Why not just buy a 240V light bulb.

I didn't even know they made them.
I googled them. This might help me out in the future.

 

[Bill Z]

Thanks for all of your responses. I have the original owners manual and aside from reconfiguring some leads on the switch and starting relay, it makes no mention of anything other than a standard 60 watt bulb, preferably rough service when set up for 240 volts.

It may be overkill, but I still want to run it on 240 volts, so I'll remove the lamp wiring and run a separate cord/plug from it to a nearby 120 volt outlet.

 

[sberry]

That works.

 

[prostreetamx]

That only applies to existing grandfather range and dryer circuits.

If there is a 4-wire range or dryer outlet, then the appliance needs to be converted to 4-wire...

NEVER run neutral current on a grounding conductor. U can kill someone doing that...

Most of the 240v units I hooked up for the recent Home Depot trade show were prototypes and all were brand new. I understand that residential wiring today requires 4 conductor outlets but almost every unit I touched had a shared neutral and ground terminal. Some had a removable bonding jumper but most hooked the neutral to the same terminal that grounded the chassis. Since almost all of these were made overseas where everything is already 240v hot to neutral, they have different standards. They still seem to be able to get our UL listing. Personally I would not use a ground for a neutral conductor, it's just not safe.