Parralell Circuits

[michael nye]

I have ran into a scenario here in our rural town that the older houses date back to the early 1900's and on an inspection the other day I found that the range is wired with two old 3 wire circuits of 10-3 no ground two neutrals, four hots, landed on an 40 amp breaker, I know the code states in this instance the 40 amp may never be on 40 amp unless in conduit? How about the two 10's I am sure there is enough road for power but the outside peramiters? Any technical assistance would go a long way thankyou

 

[bennie]

Re: Parralell Circuits

Huh?

 

[Ed MacLaren]

Re: Parralell Circuits

Bennie,
You can see how difficult it is to communicate about a technical subject, if we don't all speak the same "language".

Ed

 

[michael nye]

Re: Parralell Circuits

If you dont know what I am talking about through he info I presented then you havent done very much work in the field and should put on your bags sometime

 

[iwire]

Re: Parralell Circuits

Now that's funny, Bennie and Ed you better hit the books!

By michael nye

I know the code states in this instance the 40 amp may never be on 40 amp unless in conduit?

I have been in the trade a while and have no idea what the heck you are talking about here.

 

[russellroberts]

Re: Parralell Circuits

Just as I suspected!

Ed and Bennie are EE students who live in a dorm room,play loud music, and have never worked in the field!

russellr

 

[michael nye]

Re: Parralell Circuits

OK, let's stat by apologizing, then the topic.

Two old 10-3 romex no ground, that means there is not a ground in the wire with the other conductors. Then There are two conductors Black, two Red, two white. Romex I will have to check but I thought it is only rated for 30 amps, but what we have is two of these romex parralelled on a 40 namp braker feeding a range. that is two blk representing 110 and two red representing 110 and the two whites as the return. I hope this is more to the language. Thanks

 

[iwire]

Re: Parralell Circuits

Short answer is not code compliant now, but if it is existing and has been working for many years, IMO no big deal.

With a 40 amp breaker all you are asking of each 10 AWG is 20 amps each maximum assuming these two 10/3 RX are approximately the same length.

As to no ground conductor, that has been the Norm for electric ranges until recently.

Now Bennie and Ed turn down that music and get studying.

 

[bennie]

Re: Parralell Circuits

Michael: Apology not necessary, only a clarification. Are you a home inspector?

[ May 13, 2003, 08:04 PM: Message edited by: bennie ]

 

[hurk27]

Re: Parralell Circuits

Bennie
What year was it that the NEC stoped allowing parralleling smaller than #1 It might of been allowed back then?

But Dad I don't want to go back to school

[ May 13, 2003, 08:37 PM: Message edited by: hurk27 ]

 

[bennie]

Re: Parralell Circuits

Hurk: #1/0 is the smallest conductor permitted, for parallel operation, with overcurrent protection based on the total sum of the ampacities.

Smaller sizes are permitted provided they are only for voltage drop. The overcurrent protection can not exceed the ampacity of a single conductor. This is engineering design, it is not in the code book.

Conductors smaller than #1/0 have never been permitted. The reason is the impedance thing.

 

[cm]

Re: Parralell Circuits

Was the place ever remodeled?did it have a cooktop and wall oven, maybee somone was too cheep or lazy or dumb to replace it, Ive worked on lots of old houses and never seen what you described.How old is the romex is it silver braid or tar covered

 

[iwire]

Re: Parralell Circuits

2002 NEC For lighting circuits: 14 AWG copper; 20 AWG copper or larger conductors shall be permitted in parallel, provided the ampacity is equivalent to at least that of 14 AWG copper.

620.12 Minimum Size of Conductors.
The minimum size of conductors, other than conductors that form an integral part of control equipment, shall be in accordance with 620.12(A) and (B).
(A) Traveling Cables.
(1) Lighting Circuits. For lighting circuits: 14 AWG copper; 20 AWG copper or larger conductors shall be permitted in parallel, provided the ampacity is equivalent to at least that of 14 AWG copper.

[ May 13, 2003, 09:47 PM: Message edited by: iwire ]

 

[bennie]

Re: Parralell Circuits

Here is some information everyone needs to know.

562 No. #14 THHN Cu. wires can be installed in a 4 inch conduit.
This means 261 in parallel for hot, 261 in parallel for ground/neutral, as long as this circuit is connected to a 8 amp overcurrent device.

[ May 13, 2003, 09:50 PM: Message edited by: bennie ]

 

[roger]

Re: Parralell Circuits

Bennie and Ed are room mates?

I bet Charlie E hangs at their place too.

Roger

[ May 13, 2003, 10:02 PM: Message edited by: roger ]

 

[russellroberts]

Re: Parralell Circuits

Roger, how would you like to be the instructor of that class?

 

[roger]

Re: Parralell Circuits

Russel, that would be way to much for a human being to endure.

Roger

 

[michael nye]

Re: Parralell Circuits

The wire is that silver outer coating and no I am not a home inspector, I have been in the trade a long time, and have seen this before and know it works, I started working for the Building Dept. here in Susanville Ca, and with that am really questioning things I dont understand the real dirt of the things I've been doing for years. I find the more I learn the less I knew and accept that I need to crack the books, talk with you guys whatever it takes and I will always be learning. As far as the p-circuits I found everything my 99 could offer and it was'nt helping. Thanks again

 

[jtb]

Re: Parralell Circuits

Things to check:

1. Romex is same length, same insulation, same pathway and same size/ampacity.

2. Breaker is listed for 2 wires per pole. This might be the rub here.

3. Spelling.

I would recommend a change regardless.

Art. 310.4 Conductors in Parallel

[ May 14, 2003, 11:46 AM: Message edited by: jtb ]

 

[bennie]

Re: Parralell Circuits

Michael: I have been active, in the trade, for over 50 years. I think Ed has too. I learn something new every day.

There is some of the best pundits, in the trade, on this forum.

No offense intended but " are you putting us on?"