Amateur electroclinician, replacing a power plug

yotes · February 2010

I'd like to replace the wonky power plug on my stereo, but the replacement plug I bought for it seems to be rated for 125V/15A. This country and most of this continent runs 220V so it's a mystery why they'd even sell these plugs if they didn't actually work.

Would using it cause any problems? It's not like the stereo is going to pull more than maybe 100W at the most.

But I would really much prefer not to burn down our house, if at all possible.

Iceman.USAF · February 2010

Not an electrician persay, but I'm pretty sure that would cause major issues. I wouldn't do it.

Typhoid Manny · February 2010

that's the kind of thing where it'll probably work okay most of the time, but when it fails it'll set your shit on fire. you generally don't want to fuck around with stuff you're plugging into the wall

Pheezer · February 2010

Before anyone can say if this is safe at all, you need to determine what the power draw on the stereo is (how many Watts it can pull out of the wall, not how many it puts out), and what your circuit breakers are rated to allow for current.

If the stereo pulls 100 W @ 220 V you're pulling 0.5 amps, roughly. That's equivalent to 1.0 amps at 110V. So the wire isn't going to melt in any way from what you're drawing through it.

The rule you're looking at here is Watts = Volts * Amps (current). So to think of it a different way, 125 V @ 15 amps is equivalent to drawing 250 V @ 7.5 amps. In either case, it doesn't sound like your stereo will pull more than that and anyhow, I don't know what walls are wired for in europe but in Canada 15 amps at 125 V is a fucking lot of electricity.

So if you want to rely on what I recall from high school physics and from wiring up stage lighting without having killed myself yet, you're fine. The cord you bought isn't faulty, it's just labeled for a different voltage.

Pheezer · February 2010

ps I know I'm not an electrician either but unless you've got some reasoning behind your post, don't make it. It's pretty quick to prove whether or not watts = voltage x current via google (hint: I was right). Saying "I think you'll blow up your house" is silly as all fuck, especially if you can't explain why you think that in a way that can be verified or disproved.

Slo · February 2010

The main thing is if the device is supposed to run on 220 or 120. If its meant for 120, putting it on 220 adds an extra electrical phase to the device, which is bad. Especially for audio equipment, as it can really screw up the internal workings of the device.

IM ASSUMING the stereo is normally used at 220, then theoretically using the plug for such an endeavor would be fine. What confuses me is that 220 and 120v plugs are completly different shapes, so I dont understand how you could plug it into a wall somewhere.

yotes · February 2010

If the stereo pulls 100 W @ 220 V you're pulling 0.5 amps, roughly. That's equivalent to 1.0 amps at 110V. So the wire isn't going to melt in any way from what you're drawing through it.

The rule you're looking at here is Watts = Volts * Amps (current). So to think of it a different way, 125 V @ 15 amps is equivalent to drawing 250 V @ 7.5 amps. In either case, it doesn't sound like your stereo will pull more than that and anyhow, I don't know what walls are wired for in europe but in Canada 15 amps at 125 V is a fucking lot of electricity.

This is exactly why I thought it could be okay. There's no way in hell it would ever need >1875W. Just looking for qualified opinions (real electricians, feel free to speak up!)

The main thing is if the device is supposed to run on 220 or 120. If its meant for 120, putting it on 220 adds an extra electrical phase to the device, which is bad. Especially for audio equipment, as it can really screw up the internal workings of the device.

IM ASSUMING the stereo is normally used at 220, then theoretically using the plug for such an endeavor would be fine. What confuses me is that 220 and 120v plugs are completly different shapes, so I dont understand how you could plug it into a wall somewhere.

Yeah, the device is 220V and it's been in use for 15+ years so that's not the issue, the plug has just become touchy in the recent past.

And no, it doesn't make any sense that there would be a Thailand-sized plug rated for Japanese/North American outlets, but that's just one of many things that don't actually make sense here, I try not to think about it too hard.

Slo · February 2010

So the plug ends are the same?

Go for it, its probably just a dumb labeling error.

If the plug ends match up, the plug @ 220v for 7.5A would typically use SMALLER wire or prongs than one of 120v @ 15A

You should be fine.

(Also, been working as an electrician 'pprentice for 6800 hours, basically a real one!)

PracticalProblemSolver · February 2010

Slo wrote: »

The main thing is if the device is supposed to run on 220 or 120. If its meant for 120, putting it on 220 adds an extra electrical phase to the device, which is bad. Especially for audio equipment, as it can really screw up the internal workings of the device.

IM ASSUMING the stereo is normally used at 220, then theoretically using the plug for such an endeavor would be fine. What confuses me is that 220 and 120v plugs are completly different shapes, so I dont understand how you could plug it into a wall somewhere.

He is in a foreign country where 220 is the voltage between a single live and neutral, unlike the US single phase system where it would be the voltage between two legs.

Penny Arcade

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