Two 240v Outlets for one 40 amp Wire?

Reply

  #1  
Old 03-10-05, 07:16 PM
Member
Thread Starter
Join Date: Jan 2004
Location: Harrisburg, PA
Posts: 481
Two 240v Outlets for one 40 amp Wire?

Hey,

I want to move my washer/dryer out of the kitchen (yes, kitchen) and on to the other side of the wall where the stove is.

Can I have two 240v outlets off the same 40 amp wire ...just like we have multiple 110 outlets on a run of 12/2 wire?

Thanks in advance.
 
Sponsored Links
  #2  
Old 03-10-05, 08:36 PM
Member
Join Date: Sep 2000
Location: United States
Posts: 18,497
This is no good for many reasons, not the least of which is that you cannot safely run your dryer on a 40-amp circuit. Unlike most 120-volt circuits, most 240-volt circuits are not "general purpose".
 
  #3  
Old 03-11-05, 07:48 AM
Member
Thread Starter
Join Date: Jan 2004
Location: Harrisburg, PA
Posts: 481
Thanks for the reply. I won't do it then.

However, can anyone help me understand why?

John: "...you cannot safely run your dryer on a 40-amp circuit." Why is that the case when I thought that as long as the amps were more than what will be drawn, is OK.

Since we know that plugging a 2 amp device into a 20 amp circuit is certainly safe, why is it different from plugging a 30 amp device into a 40 amp circuit?

Thanks for any info you have on that.

Tony
 
  #4  
Old 03-11-05, 08:16 AM
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,973
The difference is that a two amp device is designed to be plugged into a 15 or 20 amp crcuit.

A dryer is designed to be plugged into a 30 amp circuit. It is not designed to be plugged into a 40 amp circuit.
 
  #5  
Old 03-11-05, 08:18 AM
Member
Join Date: Sep 2000
Location: United States
Posts: 18,497
When an appliance is designed, it is designed knowing that it needs to handle circuits protected by certain breakers. For example, a lamp manufacturer knows that the lamp might be plugged into either a 15-amp or a 20-amp circuit, and designs accordingly. But they know that the lamp should never be plugged into a 30-amp circuit, so they don't design or test it for that. A malfunctioning lamp might catch fire if used on a 30-amp circuit, where the same fault on a 20-amp circuit might shut down before the lamp caught fire.

The same considerations apply to your dryer. It's safe on a 30-amp circuit, but perhaps not on a 40-amp circuit.
 
  #6  
Old 03-11-05, 08:34 AM
Member
Thread Starter
Join Date: Jan 2004
Location: Harrisburg, PA
Posts: 481
Ohhhhhh. Thanks for that great info, folks.

Can anyone think of a way to attach the dryer AND the oven to the same wire? Or is it just impossible?

I'd even be willing to buy a new 30amp oven and drop the breaker to 30 amp to avaiod the new wire insatllation (which would be over double the price of a new oven, Im sure).
 
  #7  
Old 03-11-05, 09:04 AM
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,973
Why do you insist on pursuing this course of action? There is no practical way to do what you are asking.

I doubt that installing a new circuit would be very expensive, compared to the cost of a new oven.
 
  #8  
Old 03-11-05, 11:31 AM
Member
Thread Starter
Join Date: Jan 2004
Location: Harrisburg, PA
Posts: 481
I haven't actually verified that the circuit is 40 amp because its in a rental of mine. I JUST looked at a home for sale today and the oven circuit was 30 amp!

What if the circuit for my oven is 30 amp ....THEN could I attach a 2nd outlet for the 30 amp dryer?

I am looking for an alternative to installing a new 30amp wire run inside a 2-story apartment which would require many of hundreds of dollars and possible over $1000 of ripping ceilings/walls up and remodeling to run a new wire.

If it's possible to have 2 outlets on a 30 amp circuit, wouldn't YOU avoid wasting a thousand dollars?
 
  #9  
Old 03-11-05, 12:10 PM
hornetd's Avatar
Member
Join Date: Aug 2001
Location: Maryland
Posts: 695
210.23 Permissible Loads.
In no case shall the load exceed the branch-circuit ampere rating. An individual branch circuit shall be permitted to supply any load for which it is rated. A branch circuit supplying two or more outlets or receptacles shall supply only the loads specified according to its size as specified in 210.23(A) through (D) and as summarized in 210.24 and Table 210.24.

Multiple outlets on a thirty ampere circuit is normally done to allow for the movement of equipment rather than for additional load. The code requires that the circuit be capable of carrying all of the load connected to it. The combination of the dryer and the oven would exceed the ampacity of the circuit.
--
 
  #10  
Old 03-11-05, 12:15 PM
Member
Join Date: Feb 2002
Location: port chester n y
Posts: 2,117
The rating of the circuit-breaker, not the ampacity of the conductors, determines the rating of a Branch-Circuit (BC) . If you have 40 amp conductors, and need a 30 amp B-C, simply replace the 40 amp C-B with one rated at 30 amps.

The relevant Art. for muti-outlet B-C's is 210.23, Permissible Loads. A 40 amp B-C in a dwelling is restricted to cooking appliances only. For a 30-amp B-C with multiple outlets, 210.23 reads----- " A 30-amp B-C shall be permitted to supply--- utilization equiptment in any occupancy. Any cord/plug (load) shall not shall not exceed 80% of ( 30 amps.)".

You will need to consider the restriction of Art. 210.23 which reads----" In no case shall the ( connected) load exceed the B-C rating". If we estimate the dryer load at 25 amps, then the "margin" for the 2nd load is 5 amps.
 
  #11  
Old 03-11-05, 06:17 PM
Member
Thread Starter
Join Date: Jan 2004
Location: Harrisburg, PA
Posts: 481
Thanks guys, I do appreciate your time.

Since the stove AND the dryer would be permanent appliances, the load would be too high.

I was thinking that since my breaker trips when I run the microwave with the fridge and window A/C running, I just turn off the A/C while I cook my meal. I thought the same thing could be done with this situation; just don't run the dryer when cooking.

I wonder if I'm vilating code by having my microwave plugged into that circuit then.

Thanks again folks!
 
  #12  
Old 03-11-05, 07:09 PM
Member
Join Date: Jan 2004
Location: Oregon
Posts: 1,219
Having a fridge and a microwave and an AC all plugged into the same circuit at the same time does not violate code, but only by a technicality. The code applies to the installation of the circuits, not what the customer might plug into the circuits. The code does apply to permanently fastened in place appliances, but when you talk about an in window air conditioner, or a counter top microwave, then you are not really 'permanently fastened in place'.

Whenever the NEC has a say in the matter, circuits are always sized larger than the loads they serve. If the stuff you describe above were 'permanently fastened in place', then it would be a code violation. Most inspectors, for example, require that a wall mounted microwave oven have a dedicated circuit. Same for a permanently mounted air conditioner.

If you are tripping the breaker on a regular basis, then you really should upgrade, but getting the circuit split into several new circuits. Circuit breakers are not actually designed to be run at full capacity for extended periods of time.

On your original issue: you should find out what the amperage rating is of both the stove and dryer circuits (look at the circuit breaker). Then check the actual wire used, and see what the gage is and if it is three wire or four wire. You may be able to do something along the lines of using the current range circuit to feed the dryer, and the current dryer circuit to feed the range...but there is not enough information to go on in your descriptions.

-Jon
 
  #13  
Old 03-12-05, 07:52 PM
Member
Join Date: Nov 2004
Location: CA
Posts: 2,041
Stoves typically need a 40 amp circuit, so you cannot downsize the breaker.

As for the dryer, others have addressed the codes. I will offer a practical reason NOT to do this: The dryer is designed for a 30 Amp circuit. It has heating elements. If something goes wrong, the wiring inside the dryer is designed to handle the 30 amps, and in the event of a short, the breaker trips. If you connect this to a 40 amp circuit, a fire in the dryer could easily result before that 40 tripped.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
'