# Clothes dryer circuit



## kg7879 (Feb 3, 2014)

I do not do residential work and I can not find my answer in the code book.

How is a clothes dryer branch circuit calculated?

It seems most guys just put the circuit on 30 amp breaker with number 10's.


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## Dennis Alwon (May 9, 2009)

Most dryers require 30 amps but for service calculated you must use 5000 watts unless the dryer is larger. 220.54


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## kg7879 (Feb 3, 2014)

My dryer is pulling 30.5 and 22 amps. The wire that is drawing 30.5 has a slight discoloration. I took the readings right when I started the dryer so I do not know if the amperage would go down eventually after the heating element got up to temperature.

Should I be concerned? Like I said I do mostly industrial heavy commercial work so I do not know if 30.5 is normal.


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## ponyboy (Nov 18, 2012)

Read the nameplate. You'd think a guy who does industrial heavy commercial work would know all about current and wire sizes. 


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## Black Dog (Oct 16, 2011)

kg7879 said:


> My dryer is pulling 30.5 and 22 amps. The wire that is drawing 30.5 has a slight discoloration. I took the readings right when I started the dryer so I do not know if the amperage would go down eventually after the heating element got up to temperature.
> 
> Should I be concerned? Like I said I do mostly industrial heavy commercial work so I do not know if 30.5 is normal.


Either that dryer is huge or there is something wrong with it..


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## kg7879 (Feb 3, 2014)

ponyboy said:


> Read the nameplate. You'd think a guy who does industrial heavy commercial work would know all about current and wire sizes.
> 
> 
> Sent from my iPhone using Tapatalk


My initial question was about the calculation of the dryer circuit when there is obviously no nameplate to go off of when they are building the house. 

I could not find a branch circuiting rating in the code book for a dryer. So in absence of a name plate I was curious how contractors decide on a 30 amp circuit. I did not know if a 30 amp dryer is just the standard.


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## 480sparky (Sep 20, 2007)

Why are you worrying about how the circuit is calculated when it's being overloaded?


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## kg7879 (Feb 3, 2014)

480sparky said:


> Why are you worrying about how the circuit is calculated when it's being overloaded?


Just out of curiosity. Since the contractor does not have the nameplate of the dryer when they are building the house I was curious on how they calculated it. I went to the code book and could not find an answer.

As far as the overload I did not know if this was normal. The dryer name plate stated 28 amps, but I thought maybe the dryer draws a little more at first to get the heating element up to temperature and then might drop off.


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## bkmichael65 (Mar 25, 2013)

kg7879 said:


> Just out of curiosity. Since the contractor does not have the nameplate of the dryer when they are building the house I was curious on how they calculated it. I went to the code book and could not find an answer.
> 
> As far as the overload I did not know if this was normal. The dryer name plate stated 28 amps, but I thought maybe the dryer draws a little more at first to get the heating element up to temperature and then might drop off.


220.54 is where you want to look for dryer loads


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## 3DDesign (Oct 25, 2014)

Show me a residential electric clothes dryer with an installation guide does not require a 30 amp circuit.
Whirlpool has one with a steam option that uses a water line. Even it is 30 amp.


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## telsa (May 22, 2015)

"Congress set the initial clothes dryer standard in 1987, outlawing constantly-burning pilot lights in gas dryers. DOE published a final rule in 1991 establishing the first performance-based standards for clothes dryers, which became effective in 1994"

http://www.appliance-standards.org/product/clothes-dryers

Electric dryers are also covered by the standard -- which AFAIK has been adopted by Canada -- entirely. 

( Just one more reason why America and Canada are one unified market.)

So all General Contractors now expect to see NEMA 14R-30 receptacles. 

( Previously, 10R-30 receptacles.)

The NEC specifies that the minimum wire size, then, is #10 -- for field wiring.

A quick inspection of many dryer cords shows that they are actually #8s for the hots.

The cord is not long, and the local air temperature, proximate to the machine, is certain to be elevated. Hence, the appropriateness of #8 conductors.

And that is that.


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## btharmy (Jan 17, 2009)

Where would you buy a "dryer receptacle" that is anything other than 30 amps anyway?


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## Bootss (Dec 30, 2011)

Maybe your motor is not coming out of "start "and that's why you have an overload or something.
:thumbup::thumbup::vs_shocked::vs_boom:


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## Bootss (Dec 30, 2011)

Perhaps this dryer needs to be cleaned out blow all the dust and lint out of the motor and dryer. The vent may be plugged up also Perhaps it needs cleaning too. Just a thought.
:thumbup::thumbup:


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## wendon (Sep 27, 2010)

What's your amperage on the neutral wire? Does it have a 4-wire pigtail?


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## Dennis Alwon (May 9, 2009)

3DDesign said:


> Show me a residential electric clothes dryer with an installation guide does not require a 30 amp circuit.
> Whirlpool has one with a steam option that uses a water line. Even it is 30 amp.


I have hooked up 240v 20 amp dryers. In fact I wired a single unit that was both a washer and a dryer. It fit under the counter. I think it was a 220 branch circuit


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## Dennis Alwon (May 9, 2009)

3DDesign said:


> Show me a residential electric clothes dryer with an installation guide does not require a 30 amp circuit.
> Whirlpool has one with a steam option that uses a water line. Even it is 30 amp.





btharmy said:


> Where would you buy a "dryer receptacle" that is anything other than 30 amps anyway?



I have hooked up 240v 20 amp dryers. In fact I wired a single unit that was both a washer and a dryer. It fit under the counter. I think it was a 220 branch circuit


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## Dennis Alwon (May 9, 2009)

Be clear that even though the dryer is rated 20 amps you still need to calculated the load at 5000 watts as I stated earlier-- 220.54-


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## backstay (Feb 3, 2011)

99.99 % are a 30 amp circuit. That said, I had a washer/dryer single unit that required a 40 amp min circuit. It was a remodel job and I was lucky to find out before the the rock went on.


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## Nutmegger777 (Mar 14, 2014)

Dennis Alwon said:


> I have hooked up 240v 20 amp dryers. In fact I wired a single unit that was both a washer and a dryer. It fit under the counter. I think it was a 220 branch circuit


I clearly remember hooking up an LG two-in-one washer/dryer combo the size of a dishwasher. It was ventless -- they run the dryer exhaust through a condenser, thus removing the moisture from the air that it blows out. 

The manufacturer was _recommending_ a dedicated 15A 120V circuit, so even though the customer asked for one of those, technically it could be on virtually any circuit in the house that has a 15A receptacle.


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## suffolkmike (Dec 19, 2011)

I had one of those 120v 15a washer/dryers. It was both washer and dryer in one step. Put dirty clothes in and 3 hours later you pulled out a wrinkled mess of clothes. I thought it was cool, the wife gave it a WWA tilte " the Wrinkler". Seriously though, check for a loose connection.


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## Dennis Alwon (May 9, 2009)

Nutmegger777 said:


> I clearly remember hooking up an LG two-in-one washer/dryer combo the size of a dishwasher. It was ventless -- they run the dryer exhaust through a condenser, thus removing the moisture from the air that it blows out.
> 
> The manufacturer was _recommending_ a dedicated 15A 120V circuit, so even though the customer asked for one of those, technically it could be on virtually any circuit in the house that has a 15A receptacle.


It may have been a 120v-- I can't remember but it must have been because we are still required to run a 120v circuit for the laundry


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## Jerome208 (May 10, 2013)

backstay said:


> 99.99 % are a 30 amp circuit. That said, I had a washer/dryer single unit that required a 40 amp min circuit. It was a remodel job and I was lucky to find out before the the rock went on.


What type of power connector did this setup use? 14-30?


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