elec question RE 220V outlets

[Inspector507]

Actually this is from the manufacturer of my welder, who sells a UL listed product.

<font color="blue"> Using the following instructions, have a qualified electrician connect
a receptacle (NEMA 6-50R Type) to the power lines at the fuse
box. Three #10 or larger copper wires are required if conduit is
used. For long cable runs over 100', #8 or larger wire in conduit
will be needed to prevent excessive voltage drops. Fuse the two hot
lines with 50 ampere super lag type fuses as shown in the following
diagram. The center contact in the receptacle is for the grounding
connection. A green wire in the input cable connects this contact
to the frame of the welder. This insures proper grounding of the
welder frame when the welder plug is inserted into the receptacle.
If a separate disconnect switch is used, it should have two poles for
the two hot lines and both should be fused for 50 amperes. </font>

 

[VA_Joe]

Very interesting - learn something new each day. Seems like a loophole ripe for abuse (i.e. plugging an oven into an outlet meant for a welder). Thanks for the correction.

 

[sparkkky]

By the NEC you can not install a breaker that is rated at more amps than the wire!

Some electricans installed 40A breaker on 30A wire because of the start up load for A/Cs and the NEC put a stop to that along time ago.

Insp. I am surprised at you!

 

[mudcat]

SPARKKKY? /forums/images/graemlins/confused.gif You don't read the code book. Do you? /forums/images/graemlins/shocked.gif110.3.B /forums/images/graemlins/cool.gif

 

[sparkkky]

Code book? Not sure thats in my 1996 NEC, if I can find it I'll look an see.

No I missed that one, ticks me off that when I go to the trouble to learn standards they write one like that!

The only instructions I get around here is being told to hook that up.

Should I put, I don't remember the whole **** book in my Sig?

 

[Inspector507]

Joe,
A NEMA 6-50R outlet will not accept a range plug. That would take a NEMA 10-50R or a 14-50R outlet.

 

[VA_Joe]

All that I am saying is that if person A installs an outlet for one purpose according to one set of assumptions (i.e. for welder) and person B (a new owner, renter, etc) decides to use it for something totally different - I can envision the possibility of something very bad happening.

In the case of an HVAC circuit - the reason they allowed leeway is because the compressors are hardwired (i.e. no possibility for confusion) and breakers are not as tolerable to surges as fuses.

In any event - I think Mark got more advice than he ever envisioned /forums/images/graemlins/grin.gif.

Joe

 

[Inspector507]

<font color="blue"> In any event - I think Mark got more advice than he ever envisioned </font>

I'm sure he did /forums/images/graemlins/grin.gif

When I do inspections, I can't "expect" I have to inspect. But I do have to look at the current application/installation and approve it or not, according to the currently accepted version of the NEC®.

 

[sparkkky]

Under 110.3B unless Marks welder comes with any instructions included in the listing or labeling like Inspectors did, he could then be against code.

Looks like 630.12B pretty much covers it.

I will still run dedicated 50A circuits to any welders I wire, including my own.

 

[phantom309]

Thanks much for all of the great info fellas! I'm not 100% sure what I'll do yet, but I have a little time before I need to decide for sure.

I do have a big honkin "extension cord" as was mentioned. It's made of 2/0 cable that the utility company uses for overhead service entrance. The downside of it is that is is about 200 feet long and the length, combined with the heavy wire make it pretty bulky. But I don't want to cut it up as I have used it to reach things quite aways from the shop/garage. My neighbor has one that is 300 feet (they were cut from the same 500 ft roll). I've plugged one into the other a time or two to do some welding at a distant barn!

I got a chuckle out of the comment about some dummy plugging a stove into a welder outlet (or was it the other way around). GUILTY AS CHARGED!

Am I the only one who's first 220V welder was powered off of a dryer outlet? That's what I did for years. In my defense, this practice was suggested in a welding book I bought back when by Richard Finch and Tom Monroe.

Here's a new question for you:

How many amps are required by elec furnaces? I'm thinking of going that route for the "office" I'm going to finish off in the shop (want to keep all flamables (propane) out of the shop). A book I have said to plan on 20,000VA for an elec furnace. Yikes, that's like 90 amps! That will sure eat into my ever shrinking 200A service. Does that use a single 220V circuit or two separate smaller ones? I haven't owned a home with elec heat for years but if I remember right when I checked some fuses in a elec furnace in our first home years ago, there were four of them, not two.

Are there smaller furnaces that would be closer to 10,000VA? I'm only going to heat about 900 sq ft and it will be VERY well insulated.

I should have done my homework earlier. I'm learning that simply going and buying the "best and biggest" at the local box store isn't necessarily a great idea. It's starting to look like what they sell is generally simply the cheapest stuff available, fit for a small rent house. =(

Thanks again!

Mark