Can you safely change a four-prong electric dryer outlet to a three-prong 240V air conditioner outlet?

Answer 1

The 4 prong receptacle should be more in line with the latest wiring code. It is best to change the plug or the cord on the appliance you wish to use. If you have a 4 prong outlet, the purpose is to isolate the neutral from the ground.

There are numerous examples mentioned in Wiki s but they all amount to requiring that there be no link between the neutral terminal of the device [appliance] and the frame.

It is, however, allowed [by the NEC, unless disallowed locally by the "authority having jurisdiction"] to install a link to the neutral terminal from the chassis if there is already a three prong outlet existing.

ALWAYS CHECK WITH YOUR LOCAL WIRING SAFETY OFFICE BEFORE YOU ATTEMPT TO CHANGE ANYTHING ON POWER MAINS OUTLETS

IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB

SAFELY AND COMPETENTLY

REFER THIS WORK TO QUALIFIED PROFESSIONALS.

If you do this work yourself, always turn off the power

at the breaker box/fuse panel BEFORE you attempt to do any work AND

always use an electrician's test meter having metal-tipped probes

(not a simple proximity voltage indicator)

to insure the circuit is, in fact, de-energized.

Answer 2

For USA, Canada and countries running a 60Hz supply service

If you're asking this question you shouldn't be installing an electrical service.

This type of question usually means you aren't ready to do this yourself. Study some electrical textbooks and the National Electrical Code and work the answer out for yourself, or call a professional electrician.

If someone were to give you an answer here, you might attempt to do something you shouldn't be doing, and that may cost someone a shock, a home fire, or their life.

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This will vary by state. Turn off the power and remove the old outlet. If there are 4 wires present then it can be changed. If not, your local inspector may be able to offer some alternatives.

For more information, see the answers to the Related Questions shown below.

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As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.

Before you do any work yourself,

on electrical circuits, equipment or appliances,

always use a test meter to ensure the circuit is, in fact, de-energized.

IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB

SAFELY AND COMPETENTLY

REFER THIS WORK TO QUALIFIED PROFESSIONALS.

Answer 3

Well, yes and no. The problem is that, chances are, you don't have a good ground for the third prong. Without the good ground changing a two prong plug two a three prong is just masturbatory: it makes you feel better but does no real good, and many think it is dangerous.

The best wayWhat you need to do is get a good ground to this fixture. Obviously, the best way is to run new wire to the panel and hook to the ground wire there. This assumes the panel is grounded, of course. If it isn't you just have to keep moving back adding grounds until you've grounded everything before the outlet. The practical way (hack)Since many times it isn't practical to run a whole new wire, you can just add a new ground. Note, though, that this is a hackish procedure and probably doesn't meet code. You can use a new piece of green wire and run it from the outlet to a ground rod or a copper water pipe (make sure the pipe is grounded) to give yourself a good ground. It's dirty, but it works. Whatever you do...Don't ever just tie neutral to the ground pin. This is dangerous as you want your ground wire to always be ground, even in fault conditions. While it is true the neutral bus should be grounded at the panel, if you tie neutral to ground at the outlet and the neutral feed wire breaks open the ground will go live. This means the fixture and chassis of whatever is plugged into it will be electrically live. You don't want this! This is the reason new wiring is 3 wire instead of two. Either replace the feed wire or run a dedicated ground. yesyes definitely seach for it on eBay

(Home centers sell them for less than $1. Don't bother on eBay.)

CAREFUL ABOUT WHERE YOU GROUND TO!

BTW, Here in New England when upgrading, selling, etc, you have 2 'easy' options - tie a pigtail to box (ground outlet to box if box has the old bx and it tests good to panel ground, etc) or else use a GFI in every outlet. These are the rules we have. I'd get a nice tingle if I personally ran a fresh ground from pretty much any outlet/switch/appliance in our 1920's home just back to anything with a solid earth ground as now there is a dual path for stray currents in the conduit and just wire resistance alone to the panel. Be very careful when converting, please. Make sure there is an actual ground IN THE CONDUIT or a type-A (the current HD/Lowe's, etc standard spec) GFI wired to trip on Neutral fault. Remember if there is no ground, you or your family become the parallel path back to earth in case of a short or fault. And bonding and grounding are NOT the same, your main panel may be a subpanel to the meter outside, it's worth a quick goole and a glance at the panel to see if the GROUND and NEUTRAL are actually connected INSIDE, not just at the meter ouside where things get wet and frayed.

Answer 4

Answer for USA, Canada and countries running a 60 Hz supply service.

Yes, you can, and there should not be any difficulty whatsoever.

I recommend, however, that you consult an electrician and have the circuit upgraded to a 3 wire circuit and install a 3 wire duplex(2) receptacle.

<><><>

As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.

Before you do any work yourself,

on electrical circuits, equipment or appliances,

always use a test meter to ensure the circuit is, in fact, de-energized.

IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB

SAFELY AND COMPETENTLY

REFER THIS WORK TO QUALIFIED PROFESSIONALS.

Answer 5

No. Call an electrician. 50 dollars is cheap compared to having your dwelling burn up.

Answer 6

NO. They are made for different voltages, polarities etc..

Answer 7

no

Answer 8

of course