30amp dryer on 50amp power

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  #1  
Old 08-04-16, 02:12 PM
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30amp dryer on 50amp power

Our LG DLE2516W dryer has a 10-30P plug, 3 prong, one is L-shaped. We just moved into a home that seems to have a 10-50R outlet, 3 straight prongs.

1. Am I correct that I cannot simply replace the power cord on the dryer and that the DLE2516W could not handle 50 amps?

2. I've seen adapter generators that can take a 30amp source up to 50amps. Am I correct there are no adapters that can bring a 50amp source down to 30amps?

3. Are there any other alternatives to rewiring to a 30amp breaker?

Edit: Just looked in the fusebox and the one labeled dryer is green 30amp. The outlet itself says 50 amps. How can I be sure it's 30amps? And still, I can't find any 10-30 to 10-50 adapters.
 

Last edited by haplo888; 08-04-16 at 02:29 PM.
  #2  
Old 08-04-16, 03:46 PM
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Fuse boxes don't have breakers. Breaker boxes have breakers. Use a multimeter to check for power at the the suspected dryer receptacle. If it goes dead when the 30 amp breaker is turned off then it is on a 30 amp breaker. You will need to change the receptacle to 30 amps. If the receptacle box has a ground wire in addition to a neutral or is connected with metal cable or metal conduit you will need to convert your dryer to four wire following manufacturers directions and use a four wire cord set.
And still, I can't find any 10-30 to 10-50 adapters.
You probably won't. You need to change the receptacle and if a separate ground and neutral use a NEMA 14-30R with appropriate cord set.

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Old 08-04-16, 06:12 PM
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Just looked in the fusebox and the one labeled dryer is green 30amp. The outlet itself says 50 amps. How can I be sure it's 30amps?
Get a multimeter or non-contact tester (multimeter is preferable).
With dryer breaker on make sure you get power at the outlet is question.
With dryer breaker off make sure you get no power at the outlet.

Now you are sure that 30A dryer breaker is correctly labeled.
You can simply replace 50A outlet with correct type of 30A outlet. You can keep the same wire as long as it is at least 10AWG.

You probably won't be able to find an adapter unless you make your own. But replacing the outlet will be much cheaper and easier.
 
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Old 08-04-16, 07:12 PM
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Get a multimeter or non-contact tester
No, not a non contact tester if he doesn't want to guess. A test light or solenoid tester will work also. Any supposed reading by a non contact tester needs to be verified by a better test instrument so why not just use a real tester in the first place.
 
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Old 08-04-16, 09:09 PM
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Is there one you would recommend?
 
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Old 08-04-16, 09:16 PM
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Any $8-$15 analog multimeter. Do not get a digital multimeter. The cheap ones can sometimes give misleading readings.
 
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Old 08-05-16, 05:47 AM
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It is not a good idea to construct or possess a cord or adapter with a 50 amp (male) plug and a 30 amp (female) receptacle unless there is a box in the middle with a 30 amp circuit breaker.

The 30 amp plug on the dryer implies that the power source must be a 30 amp circuit of the same voltages. You may not substitute a higher amperage plug or power cord.

Although the dryer will work normally and correctly if you succeeded in connecting it to a 50 amp circuit, that would be against code. In the event of certain kinds of malfunctions there would be an added safety hazard or fire hazard if the dryer had 50 amps at its disposal.

While you might obtain and use "plain" adapters that allow plugging higher amperage appliances into lower amperage receptacles, it is also against code to install higher amperage wall receptacles on lower amperage branch circuits.
 

Last edited by AllanJ; 08-05-16 at 06:03 AM.
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Old 08-05-16, 07:20 AM
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As for accuracy, aren't we looking for a binary result, whether there is voltage or not when the breaker is thrown? Not actually testing the current, as most multimeters wouldn't go up to 50A.
 
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Old 08-05-16, 09:54 AM
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Multimeters test for voltage and continuity. Many will not do ampacity. You need something to test for voltage.
 
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Old 08-05-16, 10:44 AM
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I've confirmed that the "Dryer" breaker cuts power to the receptacle in question. Is it sufficient that the breaker says 30 on it for us to know that it's 30A? I assume the color-coded tabs are replaced when a different amperage breaker is used?

The neutral in the receptacle is twisted aluminum wires without insulation. See attached photo. ray2047, is this what you meant by metal cable or conduit?

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If not, and I don't need 4 wires, would this receptacle work as a replacement?
https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1
 
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Old 08-05-16, 11:01 AM
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Is it sufficient that the breaker says 30 on it for us to know that it's 30A?
Yes, that is what 30 amp circuit means, that it is protected by a 30 amp breaker.
ray2047, is this what you meant by metal cable or conduit?
No*, that is SE cable. Technically the installation is no longer code but it is grandfathered so you can use it with the receptacle you linked to. It won't be as safe as a modern installation. Best and safest would be to run new 10-3 with ground NM-b cable and install a 4-wire NEMA 14-30 receptacle.

*Metallic cable is cable is cable that has a metal sheath like BX cable.

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Metal conduit looks like metal pipe and has individual wires in it.

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Old 08-05-16, 06:43 PM
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The orientation of the 2 lives, red and black, shouldn't matter right?

I saw a schematic that seemed to suggest the X, Y, were switched between a 10-30 and a 10-50. But it wouldn't make any difference because both the red and black are live 120v, right?
 
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Old 08-05-16, 07:17 PM
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The orientation of the 2 lives, red and black, shouldn't matter right?
Correct. The bare neutral is the critical position.
it wouldn't make any difference because both the red and black are live 120v, right
No, both are 240 live. The neutral is used to derive 120v from one of the 240s to provide 120v for the 120 components of the dryer. The bare neutral must go to W.

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Old 08-05-16, 09:15 PM
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We have a working dryer.

Ran new vent duct while I was at it. Thank you for your help.
 
 

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