Wiring for 240 volt properly

[itsnotrequired]

I was going to go with 4x4x2ish? boxes, a pair of duplex receptacles at each one. I already have a Leviton 'slim' 20 amp gfi receptacle.

But you guys are gunna love this, I just came out of my attic... I'm seriously reconsidering just running romex through the wall... Regarding romex, I do not have to staple it behind an existing wall correct? Does it have to be secured/stapled to the attic joists? I notice my house wiring isn't secured to anything once it exits the wall... (Just talking about the #10)

4x4 boxes (two-gang) will meet code and be an easier installation than a single gang.

you are allowed to 'fish' romex behind finished spaces but if it is an insulated exterior wall, it can be a pain. sometimes the cable will come through fine but the insulation will get all messed up. an option may be romex (nm cable) in the attic and then transition to conduit running down the wall.

regarding running romex in the attic, is the attic accessed by a permanent stairs or ladder? if yes, you would need to either bore holes through the ceiling joists and run the romex through the holes (like in walls of new construction) or lay it on top of the joists. if on top, you would need additional 'guard strips' on the side of the cable, to protect it from damage (e.g. stepping on it). if the attic is NOT accessed by a permanent stairs or ladder, the methods described above only apply within six feet of the access hole to the attic. as long as your cable is not within six feet of the access hole, you can run your cable along the top of the joists (with staples) without the need for any additional protection.

if that 40 amp circuit is unused in your attic, could be a candidate for rerouting to the garage for your brew panel.

 

[itsnotrequired]

2 #10 conductors 2x2.5= 5
Largest ground counts as one 1 x 2.5 = 2.5
4 #12 (assuming the #12 are passing through as well) 4x2.25 = 9
Gfci device 2 times largest conductor 2.5x2=5

21.5 cubic inches.

Where did you get your additional 2 cubic inches?

i am assuming the 240 volt circuit has a neutral

3 #10: 3 x 2.5 = 7.5
#10 egc: 1 x 2.5 = 2.5
4 #12: 4 x 2.25 = 9
devices are two times the conductors attached to it, not simply largest in the box
2 #12: 2 x 2.25 = 4.5

7.5 + 2.5 + 9 + 4.5 = 23.5

 

[thekraken]

with a three-wire #10 pass through circuit, two-wire #12 circuit, shared #10 egc

With the shared #10 egc, if I branch off the #12 circuit to another conduit run can I use #12 egc there or do I now need to maintain #10?

 

[itsnotrequired]

With the shared #10 egc, if I branch off the #12 circuit to another conduit run can I use #12 egc there or do I now need to maintain #10?

yes, you can run #12 in the conduit with the #12 conductors.

 

[jbb3]

...

I agree that electricians follow the rules of the NEC for good reason. I only question the fact that those rules are the ONLY safe way the job could be done. I never suggested that anyone not follow the rules of the "King James version" of the NEC.

...I am not suggesting that anyone go stick their keys in an outlet to test the theory, but removing some of the fear might just make them less nervous and therefore more safe when working around electricity...
:

I'm not convinced you grasped the full intent behind Kh2o's rebuke of your post. Your rant may be perfectly fine on a forum limited to certified electricians who have at least some knowledge base in practical applications outside NEC, but in a forum such as this, it's out of place and irresponsible.

Did you ever stop to think that some who read your post should actually remain nervous about working with electricity due to lack of knowledge? The internet has opened up many things, including electrical work, to those who previously would not have attempted such tasks. In most cases, it has aided many to perform tasks successfully. In some, it has ended not so well. We have to be mindful of the information we put out there and the audience to whom it's directed.

Brew on!

 

[thekraken]

My new breakers say "75 C WIRE ONLY" but my thhn wire is 90 c (right?). What to do?

 

[user 163849]

I'm not convinced you grasped the full intent behind Kh2o's rebuke of your post. Your rant may be perfectly fine on a forum limited to certified electricians who have at least some knowledge base in practical applications outside NEC, but in a forum such as this, it's out of place and irresponsible.

Did you ever stop to think that some who read your post should actually remain nervous about working with electricity due to lack of knowledge? The internet has opened up many things, including electrical work, to those who previously would not have attempted such tasks. In most cases, it has aided many to perform tasks successfully. In some, it has ended not so well. We have to be mindful of the information we put out there and the audience to whom it's directed.

Brew on!

Why not tell them to never get near water or they will drown?

I in no way see fear based on a grossly exaggerated hazard as a positive learning/teaching tool. I choose fact over fiction when it comes to working with anything which might cause pain/harm.

 

[itsnotrequired]

My new breakers say "75 C WIRE ONLY" but my thhn wire is 90 c (right?). What to do?

use it! the 75 value means you can't exceed the 75 degree ampacity rating of the conductor, even if the conductor is rated for higher temps (90). since we are talking about #10 and #12 conductors, we are limited to 30 amp and 20 amp anyway, regardless of the temperature rating of the conductor.

 

[UndeadFred]

You know the NEC is really so Schneider Electric can sell the new safety gizmo every few years. So many houses built before 1990 are spontaneously combusting because of not having hybrid AFCI and GFCI breakers.. Or not.

 

[itsnotrequired]

You know the NEC is really so Schneider Electric can sell the new safety gizmo every few years. So many houses built before 1990 are spontaneously combusting because of not having hybrid AFCI and GFCI breakers.. Or not.

there is an element of truth to this. after all, representative of electrical equipment manufacturers sit on the code making panels. but let's not delude ourselves into thinking the nec hasn't played an integral role in the historical decline of electrical fires and accidental electrocutions over the decades. it isn't all about forcing some new safety gizmo down our throats...like those darn seat belts and air bags in cars.

 

[podz]

there is an element of truth to this. after all, representative of electrical equipment manufacturers sit on the code making panels.

In what year did the NEC start requiring GFCI in new electrical installations? In the very early nineties, I moved into a brand-new apartment in Germany and we already had GFCI (Siemens) then (not sure what the German code at the time was).

Our house has recently went through electrical renovations and I chose a separate GFCI for every circuit that needs one. A bit more costly when the cheapest GFCI is 20 EUR each and I have like 20 of them, but I like the idea of avoiding nuisance tripping (not that they ever trip, but anyway). Having a separate GFCI per circuit also creates the problem of needing larger panels. I've seen plenty of people wire up an entire apartment behind 1 or 2 GFCIs.

 

[itsnotrequired]

as i understand it, europe adopted gfcis more quickly than the states. isn't most everything in a residential circuit on a gfci in europe? below is a chart of gfci adoption by year based on the nec. there are some slight nuances that aren't reflected in the text below but it gives a decent history:

DATES GFCI REQUIREMENTS WERE ESTABLISHED:

1971 Receptacles within 15 feet of pool walls
1971 All equipment used with storable swimming pools
1973 All outdoor receptacles
1974 Construction Sites
1975 Bathrooms, 120-volt pool lights, and fountain equipment
1978 Garages, spas, and hydromassage tubs
1978 Outdoor receptacles above 6ft.6in. grade access exempted
1984 Replacement of non-grounding receptacles with no grounding conductor allowed
1984 Pool cover motors
1984 Distance of GFCI protection extended to 20 feet from pool walls
1987 Unfinished basements
1987 Kitchen countertop receptacles within 6 feet of sink
1987 Boathouses
1990 Crawlspaces (with exception for sump pumps or other dedicated equip.)
1993 Wet bar countertops within 6 feet of sink
1993 Any receptacle replaced in an area presently requiring GFCI
1996 All kitchen counters – not just those within 6 feet of sink
1996 All exterior receptacles except dedicated de-icing tape receptacle
1996 Unfinished accessory buildings at or below grade
1999 Exemption for dedicated equipment in crawlspace removed

as for costs, gfci circuit breakers are expensive. most folks implement gfci protection by installing a gfci receptacle and wiring additional outlets to the load side of the gfci device within the receptacle. this arrangement provides gfci protection at the first receptacle and anything downstream of it. just checking my local store, a 15 amp gfci receptacle is $12 while a 15 amp gfci circuit breaker is $32, nearly triple the cost.

 

[jbb3]

as for costs, gfci circuit breakers are expensive. most folks implement gfci protection by installing a gfci receptacle and wiring additional outlets to the load side of the gfci device within the receptacle. this arrangement provides gfci protection at the first receptacle and anything downstream of it. just checking my local store, a 15 amp gfci receptacle is $12 while a 15 amp gfci circuit breaker is $32, nearly triple the cost.

That's how I wired my shop. Each wall of outlets is on it's own circuit with the first outlet on each circuit being gfci.

 

[Kh2o]

I'm not convinced you grasped the full intent behind Kh2o's rebuke of your post. Your rant may be perfectly fine on a forum limited to certified electricians who have at least some knowledge base in practical applications outside NEC, but in a forum such as this, it's out of place and irresponsible.



Did you ever stop to think that some who read your post should actually remain nervous about working with electricity due to lack of knowledge? The internet has opened up many things, including electrical work, to those who previously would not have attempted such tasks. In most cases, it has aided many to perform tasks successfully. In some, it has ended not so well. We have to be mindful of the information we put out there and the audience to whom it's directed.



Brew on!

Thank you. What he needs to realize and itsnotrequired for that matter is us professionals really need to restrict our advice to you amateurs to stopping dead bodies on the ground problems. Not all these technicalities of strapping, box fill, conduit fill etc. I would love to debate all of these options on code in the proper place. This, as you said is not that place.

 

[itsnotrequired]

yeah, we got a bit more in-depth in this thread than we really needed to. i feel it is still important to mention the issues and let the user make a semi-educated choice. like kraken's thoughts of putting #10 conductors on a 20 amp circuit. bigger is better, right? in this example it can actually create additional problems that the amateur may not have even considered. forget code maximums on box fills, just look at it practically. working in an overstuffed box is a p.i.t.a. by the time the amateur realizes this, all the wire, boxes, etc. have been purchased and installed. what's the move now? rip everything out or stuff it in the smaller box? seems like smashing it in there is the easier option but this can lead to stressed terminations that are more susceptible to failure.

does this mean an overstuffed box is automatically some type of ticking time bomb, just waiting to burn your house to the ground? of course not. but given the option of going with an overstuffed installation or a code-compliant installation, which one makes more sense? the effort/cost between the two options is negligible so why not 'do it right' the first time?

 

[user 163849]

Thank you. What he needs to realize and itsnotrequired for that matter is us professionals really need to restrict our advice to you amateurs to stopping dead bodies on the ground problems. Not all these technicalities of strapping, box fill, conduit fill etc. I would love to debate all of these options on code in the proper place. This, as you said is not that place.

No, I'll stick to my guns. Promoting misinformation as a way of enhancing someone's safety is ridiculous. Increased apprehension of electrocution is more likely to cause an accident than the knowledge that, though electrical shock is quite likely, electrocution is much less so. And what would be the point of discussing it among those who already know?

The code book would be improved immensely if they would remove the fiction and product placement portions.

You decided that that exposing the myth that if you do not know what you are doing ,electrocution is imminent, and the the NEC is the holy word of electricity was ridiculous of me.

Since you decided to police me and censor my thoughts on the matter I have to wonder just who you think you are? What makes you feel that you have any say in what place I decide to make any statement whatsoever? And now that we know that you promote education through misinformation (or "restricted" information), why should anyone care what you say anyway?

 

[jbb3]

Thank you. What he needs to realize and itsnotrequired for that matter is us professionals really need to restrict our advice to you amateurs to stopping dead bodies on the ground problems. Not all these technicalities of strapping, box fill, conduit fill etc. I would love to debate all of these options on code in the proper place. This, as you said is not that place.

I couldn't agree more.

 

[user 163849]

Well, there we have it then.
Our electrical questions will be answered by professionals and the useflness of that information will be limited, as amateurs are only entitled to a "restricted" amount of information. And the fact that much of the NEC is of questionable value to someone building a plug in device will be kept secret. The ignorant amateur shall remain ignorant at all cost!

 

[podz]

as i understand it, europe adopted gfcis more quickly than the states. isn't most everything in a residential circuit on a gfci in europe? below is a chart of gfci adoption by year based on the nec.

...

as for costs, gfci circuit breakers are expensive. most folks implement gfci protection by installing a gfci receptacle and wiring additional outlets to the load side of the gfci device within the receptacle. this arrangement provides gfci protection at the first receptacle and anything downstream of it. just checking my local store, a 15 amp gfci receptacle is $12 while a 15 amp gfci circuit breaker is $32, nearly triple the cost.

First of all, we separate the lamp circuits and the receptacle circuits.

Lamp circuits are on 10 amp breakers and 1.5mm2 (16 awg) wiring. Lamp circuits do not contain any receptacles and do not require GFCI.

Receptacle circuits are on 16 amp breakers and 2.5mm2 (14 awg) wiring.

All receptacle circuits require GFCI. Exceptions are for permanently attached appliances (deep freezer, fridge, water pump, oil burner, etc). If the permanently attached appliance is not hardwired, then it needs to have a single-socket receptacle at least 160cm (60 inches) from the floor.

Here is a picture of a main panel I built last year. It has a 3-phase feed with 1 phase per row. On the right side, there are 2 x 20 amp breakers per phase - these feed subpanels in my kitchen and basement. On the left side, there are two GFCIs per phase. These are protecting my receptacle circuits. Of course, this box is a lot more full of wires now than it was then on go-live day.

 

[itsnotrequired]

Well, there we have it then.
Our electrical questions will be answered by professionals and the useflness of that information will be limited, as amateurs are only entitled to a "restricted" amount of information. And the fact that much of the NEC is of questionable value to someone building a plug in device will be kept secret. The ignorant amateur shall remain ignorant at all cost!

gimmie a break, no one is trying to withhold any information or keep anyone in the dark. the intent is to let folks know what the code says and what the requirements are. if they choose to ignore the requirements, more power to them, i'm not going to rat anyone out. and more likely than not they won't have any real safety issues by not meeting code. but what about the amateur that is having their work permitted and inspected? why offer anything other than code-compliant advice? and consider folks selling their homes in the future. any non-compliant wiring could be discovered during a home inspection by the buyer. now the homeowner is possibly explaining themselves to the local building inspector. or hiring an electrician to correct the issues or having to give the buyer a credit at closing so they can fix it (and more than likely, they would just pocket the money).

lots of 'if', 'possibly' and similar statements above but what has been gained by not following code in the first place? for the installations being discussed, it is pennies to make it code-compliant and in some instances, can even be cheaper. but it could cost you big money down the road, especially when selling a home.

 

[user 163849]

At what point did I give anyone any advice?

 

[itsnotrequired]

i never said you offered advice, my apologies if it was interpreted that way. but to make statements like 'the fact that much of the NEC is of questionable value' sure could be interpreted the wrong why by an amateur.

 

[user 163849]

Thank you. What he needs to realize and itsnotrequired for that matter is us professionals really need to restrict our advice to you amateurs to stopping dead bodies on the ground problems. Not all these technicalities of strapping, box fill, conduit fill etc. I would love to debate all of these options on code in the proper place. This, as you said is not that place.

The red text says it, professionals should restrict adivice to YOU amateurs. If that is not withholding truth I don't know what is, and it is equal to misinformation in my opinion.

I made my living herding electrons for most of the years from 1968 through 2006 when I retired. Though I was never restricted to cracking open a code book I still feel that should earn me something more than amateur status even among a bunch of code book waving electricians.

You guys go ahead with all the code talk and inflated safety concerns. In all the years that I worked with electricity I never met anyone doing electrical work who had never experienced an electrical shock. Even in my high voltage days I never knew anyone who was electrocuted. It seems that most electricians preaching safety knew several who were electrocuted? If so that electrician trade must be much more dangerous than microwave radios and electrical sub stations, though many of the duties are duplicated. There is no requirement that I follow your lead and withhold this valuable information from us amateurs. Even the "head electrician of planet earth" has no place deciding "what I need to realize!

 

[user 163849]

i never said you offered advice, my apologies if it was interpreted that way. but to make statements like 'the fact that much of the NEC is of questionable value' sure could be interpreted the wrong why by an amateur.

Sure, but the whole sentence pretty much explains it;

"And the fact that much of the NEC is of questionable value to someone building a plug in device will be kept secret."

My first post in this thread was to defer the answer to an electrician. Other than that I tried to bust a myth or two. Not giving anyone advice.

 

[itsnotrequired]

i guess i'm not understanding what information you feel is being 'kept secret'. your (and my) opinion on the necessity or value of various code articles is irrelevant. code is code, it is either met or it is not. an installation not meeting code isn't inherently a danger, just like an installation meeting code isn't automatically some fail-proof design. but given the option on installing something new, what advantage is gained by not following code? why not follow a widely accepted document which has been around for decades, which is written and updated continuously by scientists, engineers, inspectors, electricians, equipment manufacturers, etc., especially by someone with limited experience with electrical installations?

i guess i'll offer my advice and you can offer yours.

 

[user 163849]

i guess i'm not understanding what information you feel is being 'kept secret'. your (and my) opinion on the necessity or value of various code articles is irrelevant. code is code, it is either met or it is not. an installation not meeting code isn't inherently a danger, just like an installation meeting code isn't automatically some fail-proof design. but given the option on installing something new, what advantage is gained by not following code? why not follow a widely accepted document which has been around for decades, which is written and updated continuously by scientists, engineers, inspectors, electricians, equipment manufacturers, etc., especially by someone with limited experience with electrical installations?

i guess i'll offer my advice and you can offer yours.

I was strongly reprimanded by KH20 for stating that if contact with a live electrical circuit was as hazardous as they would have us believe there world be a lot fewer electrical workers around these days. He felt I should keep that fact to myself. I feel that it is useful information to someone starting out working with electricity as they could be somewhat more relaxed than if they thought they would surly die if the accidentally touch a wire. It's that simple. Two of his posts have indicated that this information should be withheld for the amateur's safety.

In my case we worked with "standards" much the same as code but specific to the military organization, utility or company that you work for. They are also written by engineers, scientists etc. They do not include product placement as these type of organizations usually buy from the lowest bidder (yes even the military). The standards are actually often written by the technicians who actually do the work and signed off by engineers which brings an element of common sense to them that you code guys could really appreciate if you had the chance to work with them. Most standards can easily be established by careful study of the manufacture's data.

I'm all for safety but insanity disguised as safety is a pet peeve of mine.

Let's have a beer!

 

[itsnotrequired]

ah, i see kh20's statement now. i do not agree with his statement as worded but he would need to clarify if he meant something else. and full disclosure, i spent the first ten years of my career in the power generation industry. we used our own standards, ampacity charts, etc. i think i saw one copy of the nec the entire time i was there.

then i shifted to a more commercial/industrial industry about five years ago and had to get caught up on code pretty darn quick.

 

[thekraken]

Thank you. What he needs to realize and itsnotrequired for that matter is us professionals really need to restrict our advice to you amateurs to stopping dead bodies on the ground problems. Not all these technicalities of strapping, box fill, conduit fill etc. I would love to debate all of these options on code in the proper place. This, as you said is not that place.

BUT getting to the technicalities was the intention of this thread. If I didn't care about code I would have had 220 service a long time ago.

Anyway, as these things go I completely changed my plan last minute. I ran conduit from the panel to the opposite side of the garage instead. I only had time to get the conduit up last night, pulling the wire will have to wait for later in the week.

 

[podz]

ah, i see kh20's statement now. i do not agree with his statement as worded but he would need to clarify if he meant something else. and full disclosure, i spent the first ten years of my career in the power generation industry. we used our own standards, ampacity charts, etc. i think i saw one copy of the nec the entire time i was there.

then i shifted to a more commercial/industrial industry about five years ago and had to get caught up on code pretty darn quick.

Let's be clear: most electricians feel that anyone doing work themselves is stealing bread from their table. That's why you get nasty, condescending answers when asking for information.

Plumbers are the same way. So are car mechanics...

 

[user 163849]

Podz, you are likely right, it would certainly explain a lot.

I was a little concerned when a certain individual, in one of his first posts to HBT in a different thread, closed with;

"I am new to this forum, I am taking personal responsibility to monitor this forum for these questions as amateur electricians scare me."

A red flag if I ever saw one! And as I have recently been christened with amateur status after only 38 years of experience, I take this kind of personal. It appears that he is here to single handed save us all from that huge death toll among HBT diy types!

Ain't we lucky!