Questions involving 220volt

T

TANGUS

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Oct 6, 1999
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Over the past couple of years I had gotten the impression from conversations on the forums it was not recommended to use your 220v dryer outlet for use with an electric kiln/oven or a 220v welder. Something about the performance as a result of the restriction of wattage? Does that sound right? Any body comment on this one? Is that lonely dryer 220v outlet going to go to waste in between times the dryer is in use?--thanks, Dan
 
I have no idea how you do it in the US, but I can tell you how it is over here. It all depends on the fuse in front of the outlet and the size of the wires. We have 10 amps in front of 220v, and that gives a max of 2200 watt. If you exceed that the outlet or the wire might melt or even start burning - I have seen that happen several times. If the installation isn't made especially for machines who need a lot of power I wouldn't do what you have in mind. The best thing to do is to have somebody make an installation for that oven/welder - that will cost you less than a new house when the old one is burned down :D
 
I got a 60 amp breaker on my buzz box, toasted an connection a while back, purty sparks and everything. Not unusual to do that in a weld shop either, stuff gets old, abused and worn and goes pop.
 
Check your dryer (whatever) outlet fuse or breaker. The dryer is probably 25 - 30 amps. If your welder surges more than the breaker is rated for you will have a lot of tripped breakers AND WEAR ON THE WIRING. Do not increase the current rating for this outlet without professional on-site advise. If, on the other hand, the instrument running requires somewhat less current than the line is fused for and there is a failure such as a short circuit the breaker may not trip in time to prevent further damage or hazard (DEFINATELY CAUSING WEAR ON THE WIRING - DANGER) . For situations where the in-house wiring and breaker are greater than required you can place an in-line fuse of the proper rating for the instrument in the instrument (kiln, whatever) line cord. The lower rated fuse will fail in time to prevent wiring damage within the building.

Call the equipement manufacturer or a good local electrician to verify me and get the proper fuse rating and wiring.

Also be aware that the 220 - 240 volt dryer outlet is not wired in the same manner as the more common 120 volt outlet. The 240 volt outlet has two lines of 120 volts each out of phase of each other and a third 'return' or ground line. See an electrician.

This post has been edited to add important info first not mentioned. Edits are in CAPS.

Roger
 
Like MikeS said, you are underprotecting the arcwelder, overprotecting the grinders.
Dryer outlets are anywhere from 30-50amps. Not enough for the welders surge, should you have a short or something with a grinder, whose moter only pulls, probably 8 amps@220/240V, it's fried before the breaker can get close to tripping and doing its job of protecting.
You might want to put in a sub panel. You could take off from the dryer circuit maybe. It's not that much, and you would have the proper breakers/fuses for what you need.
Like Rlinger said, might be best to see an electrician.
Also, like he said, 240V, is two 120V lines with a ground, 120V is one hot 120V line, one neutral, and one ground wire.
If a motor is rated for, say, 16amps at 120V, it will be 8amps at 240, a lot less load for your wiring to carry.
 
Moreover be sure you have 220 V american three phase equipment, analogous to european 380V three phase.
European 220V equipment is DUAL PHASE (one live and one ground wire) and will not work with american 220V three phase.
For wires checking the breaker is not enough. Check local regulations. They should state how many square mm (or inches or whatever) per Ampere is safe.
Compare the section of the conductor (not the wire, just the copper part) and the equipment you have to find out if it will put too much load on the cabling.
If so, have wider cabling installed and rigged by a competent electrician.
DON'T DO THIS YOURSELF!
THIS IS DANGEROUS, especially with american style wooden houses!
Moreover you could void any insurance you've got and incur in serious problems with the local fire dept, and regulations usually require an omologation certificate released by a qualified technician after installation.
 
PLEASE NOTE HERE! I was not talking about 3 phase power supply. I was talking single phase only. 3 phase is usually found in industrial applications in this country, and although I used to sell three phase products all the time, I am not comfortable explaining them, and won't.
 
Mike,
I believe what was alluded to is that across the pond, there may not be a "center tap" or neutral like there is over here. One side of their's is hot, the other side is ground or neutral.
Over here, both of ours are hot and measures 220 between the two and 120 from either hot side to the center or neutral terminal. Some folks may get confused with 2 and 3 wire connections thinking that each is a phase.

(Aboard US Navy ships even 120 VAC is center tapped, 60vac from L1 or L2 to ground, 120vac between the two!!!)

I tried to express this in simplest layman's terms as possible. I hope it makes sense...

C Wilkins
 
I do my own wiring because I under stand it..
but I'd say if you have to ask, hire an electrician
and live on to make knives...:D if something
happens:( you'll have the electrician to blame,
he gets paid to do it right.and you can feel
safe for your family
 
Also one of the important things to remember is the length of the run of wire. The longer the run the worse it is. You want as short a run from the panel to the outlet as possible. Three feet or less is good.
 
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