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hotinattic

@verizon.net

electrical sub panel

i need more electrical circuits in attic. I find unused 10-2 wg an 8-2 wg in attic. plan on using double 40 amp breaker in main panel to feed the 8-2 wire which will then feed sub panel through double 40 amp breaker. I will use the 10-2 for the neutral bar in sub panel and the ground wires from the 10-2 & 8-2 for the ground bar. I then will use four 15 amp breakers for the circuits I need. Does anyone see any
problems with safety wise?

Speedy Petey

join:2008-01-19
No, you CANNOT do this. Not even close.
All the conductors need to be in one cable or raceway.

Zach1
Premium
join:2006-11-26
NW Minnesota
reply to hotinattic
Speedy Petey See Profile is absolutely correct. Violates 300.3(B) which requires all conductors of the same circuit to be contained within the same raceway, cable sheath et al. and 300.3(B)(1) which pertains to paralleled conductors.

You could use the 8/2 w/g on a 40A single-pole breaker to power a small 120V sub panel. Three or, depending on loading, four 15 amp lighting circuits wouldn't be a problem.
--
Zach


mackey
Premium
join:2007-08-20
kudos:13

1 recommendation

Seriously guys, can we please NOT feed the troll?

/M


John Galt
Forward, March
Premium
join:2004-09-30
Happy Camp
kudos:8
What do you find trollish about the post?


mackey
Premium
join:2007-08-20
kudos:13

3 recommendations

1) Anonymous post
2) with no pictures
3) asking about something that will very quickly degrade into a bitter argument in this forum
4) asking about something that's clearly unsafe
5) and you don't just "find" 8/2 and 10/2 wires in usable condition but unused and going right where you want them.

/M


John Galt
Forward, March
Premium
join:2004-09-30
Happy Camp
kudos:8
1 - Anon posts are allowed on this site...for better or worse.
2 - The picture requirement is never enforced...that's a mod call.
3 - That's your opinion.
4 - It's not "clearly unsafe"...it is a violation of the Code, however.
5 - Sure you do...a (now removed) attic-mounted HVAC unit could require a 10/2 for the unit and an 8/2 for emergency heat.
--
No amount of force can control a free man, a man whose mind is free. You can't conquer a free man; the most you can do is kill him. Well, you can try to...



PSWired

join:2006-03-26
Annapolis, MD

2 recommendations

reply to hotinattic
Maybe we could discuss the lightning current carrying characteristics of the #10 and #8 grounding conductors in parallel


mackey
Premium
join:2007-08-20
kudos:13
reply to John Galt
said by John Galt:

3 - That's your opinion.
4 - It's not "clearly unsafe"...it is a violation of the Code, however.
5 - Sure you do...a (now removed) attic-mounted HVAC unit could require a 10/2 for the unit and an 8/2 for emergency heat.

3 - It's also the opinion of the forum moderators judging by the number of threads which get locked and/or deleted. I'm really surprised »Wire Size didn't get locked; »Improper ground most certainly did.
4 - That's your opinion. It's clearly unsafe to me. The "doubling up" for the neutral and ground kinda reminds me of that now-deleted thread of someone asking something similar which ended with 4 pages of arguments about exactly how unsafe that was followed by the deleting of the entire thread.
5 - Unlike adding A/C to a furnace, electric emergency heat is built into the main HVAC unit and doesn't use a 2nd circuit. While having both an unused 8/2 and 10/2 ending up in the same place /could/ happen, I find it highly unlikely.

/M


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom
said by mackey:

5 - Unlike adding A/C to a furnace, electric emergency heat is built into the main HVAC unit and doesn't use a 2nd circuit. While having both an unused 8/2 and 10/2 ending up in the same place /could/ happen, I find it highly unlikely.

/M

A heat pump indoor air handling unit most definitely has 2 separate circuits. One for the main unit and another for the electric strip heaters. Unit has 2 circuit breakers to disconnect them and 2 breakers in the Service Panel.


mackey
Premium
join:2007-08-20
kudos:13
Not always, it depends on the size of the unit. But yes, they can have 2 circuits. I was misremembering things as all the multi-circuit units I've seen actually use a subpanel near the unit which is fed from a single breaker in the main panel.

I forgot to add the 6th thing which made the OP feel like a troll to me - the name "hotinattic" sounds too close to the argument about conduit color and de-rating from a certain recent thread.

But by all means, OP if you could post some more info, preferably with pics, it would help a lot! That #8 alone might be enough for what you need (assuming you need only 120v or only 240v circuits in this subpanel).

/M


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom
said by mackey:

Not always, it depends on the size of the unit. But yes, they can have 2 circuits. I was misremembering things as all the multi-circuit units I've seen actually use a subpanel near the unit which is fed from a single breaker in the main panel.

/M

That would be quite a circuit to feed the air handler and condenser unit plus 15 kw of strip heat. The circuit would have to be jumped to feed the 2nd breaker in the air handler.


mackey
Premium
join:2007-08-20
kudos:13
Kinda. The one at my parents place used a 125A breaker in the main panel and had 2 60A breakers on the subpanel attached to the side of the unit. As it was a normal subpanel there was no jumping required, just 2 2-pole breakers. The condenser got its own circuit to the main panel as it was almost on the other side of the house.

The unit in the last place I was at was really small so it only had a single 30A or 40A breaker plus a 20A for the condenser.

/M


pete

@optonline.net
reply to hotinattic
said by hotinattic :

i need more electrical circuits in attic. I find unused 10-2 wg an 8-2 wg in attic. plan on using double 40 amp breaker in main panel to feed the 8-2 wire which will then feed sub panel through double 40 amp breaker. I will use the 10-2 for the neutral bar in sub panel and the ground wires from the 10-2 & 8-2 for the ground bar. I then will use four 15 amp breakers for the circuits I need. Does anyone see any
problems with safety wise?

The 10 awg for neutral is too small for safety. Use twisted together steel coat hangers and roofing asphalt for insulation for a safe connection. When splicing coat hangers, use emery paper to sand off the lacquer on the steel wire, otherwise smoke will result at the splices.


54067323

join:2012-09-25
Tuscaloosa, AL
reply to mackey
said by mackey:

1) Anonymous post
2) with no pictures
3) asking about something that will very quickly degrade into a bitter argument in this forum
4) asking about something that's clearly unsafe
5) and you don't just "find" 8/2 and 10/2 wires in usable condition but unused and going right where you want them.

/M

Sounds like you are an engineer.
Expand your moderator at work

kherr
Premium
join:2000-09-04
Collinsville, IL
Reviews:
·Charter
reply to pete

Re: electrical sub panel

said by pete :

said by hotinattic :

i need more electrical circuits in attic. I find unused 10-2 wg an 8-2 wg in attic. plan on using double 40 amp breaker in main panel to feed the 8-2 wire which will then feed sub panel through double 40 amp breaker. I will use the 10-2 for the neutral bar in sub panel and the ground wires from the 10-2 & 8-2 for the ground bar. I then will use four 15 amp breakers for the circuits I need. Does anyone see any
problems with safety wise?

The 10 awg for neutral is too small for safety. Use twisted together steel coat hangers and roofing asphalt for insulation for a safe connection. When splicing coat hangers, use emery paper to sand off the lacquer on the steel wire, otherwise smoke will result at the splices.



Wouldn't a flux capacitor be right for this job ....... all you need then 1.21 Gwatts .....


grobinette
Southeast of disorder
Premium,Mod
join:2001-01-27
Springfield, VA
kudos:2
reply to hotinattic
I think that he's trolling now too. Take a rest and see if he bothers to come back.


alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
You guys, admins, should start a debate on whether anon accounts should be allowed to post.

Even legitimate posts from anons tend to be non-returns (1 post never responds again).

Zach1
Premium
join:2006-11-26
NW Minnesota

2 recommendations

said by alkizmo:

You guys, admins, should start a debate on whether anon accounts should be allowed to post.

Even legitimate posts from anons tend to be non-returns (1 post never responds again).

+1 This is the only forum I frequent that allows anon posting. In fact, many put new users on post watch and a few are now asking for a brief essay about why you want to join the community.

Time is limited and I don't have nearly enough to read the multiple pages of bickering over OT nonsense nor do I have time to analyze who is stirring the pot rather than asking legit questions. I can't help but wonder if forum staples such as whizkid3 See Profile, nunya See Profile and other longtime forum regulars have curtailed sharing their knowledge and experience due to these shenanigans. IMHO, elimination of anon posting would be a good start in cutting the BS.
--
Zach


mattmag
Premium,ExMod 2000-03
join:2000-04-09
NW Illinois
kudos:3

1 recommendation

This part of the discussion needs to be posted here---> »Feedback

And, I agree the anons are causing decay to the community here.

patcat88

join:2002-04-05
Jamaica, NY
kudos:1
reply to Zach1
said by Zach1:

said by alkizmo:

You guys, admins, should start a debate on whether anon accounts should be allowed to post.

Even legitimate posts from anons tend to be non-returns (1 post never responds again).

+1 This is the only forum I frequent that allows anon posting. In fact, many put new users on post watch and a few are now asking for a brief essay about why you want to join the community.

Time is limited and I don't have nearly enough to read the multiple pages of bickering over OT nonsense nor do I have time to analyze who is stirring the pot rather than asking legit questions.

I find the anons are usually entertaining rather than draining. I tried to search for one thread I remember was particularly interesting but I got nothing but "Post » No permission to read post (forum is members only or permission denied)" responses. Search for "leek soup" in this forum. The anons usually wants to know whether to use pink or green duct tape. The regulars here respond with use hot melt tape and the anons go running away screaming from the prospect of being told how not to hackjob it.


hotinattic

@verizon.net
reply to Zach1
Thank you Zach 58, for the best answer and additional advice.


hotinattic

@verizon.net
reply to hotinattic
reply to mackey's troll accusations:

1. I tried to use my username and the system wouldn't allow it. After three trips back and forth to my email to "reset password" I gave in and went with anonymous.

2. I doubt that pictures of unused wire in attic or empty sub panels, etc. would have helped. Anyway, I was allowed to post without pictures so, not my problem.

3. The question was about safety. If the discussion devolves into
a running argument as to which of you is wiser, that is not my fault.

4. It is not clearly unsafe as John Gault observed. Rather, I would offer that the use of double breakers on both ends of the 8-2 is overkill.

5. And, mackey, you do "find" wires in the attic in useable condition. I wired many a new construction years ago (copper was cheap then) where I would stub several wires from the main panel into the attic to allow for needed additions that might be wanted later. Perhaps this was not common in your day, but I was in mine. In this case the "found" wires were 10-2 from a clothes dryer that was converted to gas, and 8-2 from a removed sauna. As to "going right where you want them" Duh, they were in the attic, right where I wanted them.

6. As to the name, hotinattic, yes I was, it was 80 outside and hotter in the attic. Seemed appropriate at the time.

7. As for calling me a Troll, go look in your mirror.

8. I am not "doubling up" for the neutral and the ground. Neutral and ground are separate.

Now Then...........

What if I said I was running a 10-2 with ground from a 30 amp breaker in the main panel to feed a 30 amp sub panel in the attic. And then installing two 15 amp breakers in the sub panel to feed two circuits. Would that be OK?

What if I said I was running a 8-2 with ground from a 40 amp breaker in the main panel to feed a 40 amp sub panel in the attic. And then installing three 15 amp breakers in the sub panel to feed three circuits. Would that be OK?

What if I said I would mount both of the sub panels side by side. Would that be OK?

What if I said I would mount both of the sub panels side by side and weld them together? Would that be OK?

What if I said I said I would cut out the redundant sides between the two boxes and leave the boxes connected? Would that be OK?

This is what I was suggestion to do but using only one sub panel rather than two and using the wires in a manner that would allow greater amperage capacity and additional safety by adding additional breakers to protect in the case of an overload in any one part of the circuits. AGAIN, the question was about safety, not compliance with the NEC.


mackey
Premium
join:2007-08-20
kudos:13
said by hotinattic :

1. I tried to use my username and the system wouldn't allow it. After three trips back and forth to my email to "reset password" I gave in and went with anonymous.

2. I doubt that pictures of unused wire in attic or empty sub panels, etc. would have helped. Anyway, I was allowed to post without pictures so, not my problem.

1. Then say that in the OP so we take you seriously.

2. Just because it's not physically disallowed doesn't mean it's not still breaking the rules.

said by hotinattic :

4. It is not clearly unsafe as John Gault observed. Rather, I would offer that the use of double breakers on both ends of the 8-2 is overkill.

8. I am not "doubling up" for the neutral and the ground. Neutral and ground are separate.

This is not what you said in your OP:
said by hotinattic :

I will use the 10-2 for the neutral bar in sub panel and the ground wires from the 10-2 & 8-2 for the ground bar.

You clearly said you were going to use both #10 wires to supply the neutral bar (singular "bar" not "bars") and both ground wires (from the #8 and from the #10) to supply the ground bar (again singular "bar" not "bars"), aka doubling up.

said by hotinattic :

What if I said I was running a 10-2 with ground from a 30 amp breaker in the main panel to feed a 30 amp sub panel in the attic. And then installing two 15 amp breakers in the sub panel to feed two circuits. Would that be OK?

What if I said I was running a 8-2 with ground from a 40 amp breaker in the main panel to feed a 40 amp sub panel in the attic. And then installing three 15 amp breakers in the sub panel to feed three circuits. Would that be OK?

The answer to both of these is the same. Assuming it's either a single pole breaker (not a double) in the main panel, or a double pole breaker in the main panel and double pole 15's in the sub with nothing requiring a neutral then yes, it's ok. You cannot use a double pole breaker in the main panel and single pole breakers in the sub as that would require 4 wires all of the same size and in the same cable: 2 hots, 1 neutral, 1 ground.

said by hotinattic :

What if I said I would mount both of the sub panels side by side. Would that be OK?

Yes.

said by hotinattic :

What if I said I would mount both of the sub panels side by side and weld them together? Would that be OK?

What if I said I said I would cut out the redundant sides between the two boxes and leave the boxes connected? Would that be OK?

No on both of these. You cannot modify the equipment unless it's approved by the manufacturer. In this particular case they would be concerned about the structural integrity of the modified panels as they must be able to contain a fault (should a cable come loose and ground out on the case) and be able to withstand people pushing on it and things falling onto it.

said by hotinattic :

AGAIN, the question was about safety, not compliance with the NEC.

The NEC exists to ensure safety. If it was safe then it would be allowed by the NEC.

/M

Zach1
Premium
join:2006-11-26
NW Minnesota

1 recommendation

reply to patcat88
said by patcat88:

said by Zach1:

said by alkizmo:

You guys, admins, should start a debate on whether anon accounts should be allowed to post.

Even legitimate posts from anons tend to be non-returns (1 post never responds again).

+1 This is the only forum I frequent that allows anon posting. In fact, many put new users on post watch and a few are now asking for a brief essay about why you want to join the community.

Time is limited and I don't have nearly enough to read the multiple pages of bickering over OT nonsense nor do I have time to analyze who is stirring the pot rather than asking legit questions.

I find the anons are usually entertaining rather than draining. I tried to search for one thread I remember was particularly interesting but I got nothing but "Post » No permission to read post (forum is members only or permission denied)" responses. Search for "leek soup" in this forum. The anons usually wants to know whether to use pink or green duct tape. The regulars here respond with use hot melt tape and the anons go running away screaming from the prospect of being told how not to hackjob it.

I must admit that many anon threads are hilarious. Now that this topic is moving toward a discussion about safe versus compliant installations (which usually end badly) complete with mention of modifying panels and welding them together(ROFLMAO), it appears as if Macky nailed it down nicely in his first contribution to the topic.

--
Zach


LazMan
Premium
join:2003-03-26
canada
reply to hotinattic
TL;DR

To answer OP's post - Can't use separate cables for a single circuit (in most circumstances...) - safe and legal way would be to run 120v@40A to a sub panel, feeding a couple of 15A or 20A @ 120v circuits... If you need 240v, re-purpose the 10/2 for a dedicated 240, as well... If you need 120/240 together, we'll, you're boned.

As an aside to some of the other posters - unless you're a mod, don't worry about moderating posts/threads... The "Hey Mods" button exists for a reason, if you have concerns about something being said.