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View Full Version : How many 15 andor 20 amp recepticles, are acceptable, on 20-amp breaker?


rr6
Nov 9, 2013, 04:21 AM
I'm installling sub-panel that is pulling off 100-amp main service panel in 12' x 16' cabin.

How many 15 and/or 20-amp receptacles are acceptable-- in general -on a 20 amp breaker?

How many 15 amp receptacles are acceptable on 15 amp breaker?

I had new codes were going to do away with all 15 amp receptacles in near future.

I have run 3 #6's and #8 ground 180 ft too 12 by 16 cabin, with 2-pole 50 amp breaker acting as my main, in a 6 space sub-panel. That leaves me four spaces.

No plumbing so NO hot water heater, only mini-fridge is planned

First space a I plan to be 20-amp dedicated mostly for window air conditioner.

2nd space dedicated for 2, 20 amp receptacles-- mini-fridge( 4-amps? ) and coffee maker( 9-amps? ) ---.

That leaves me 2 spaces for two ceiling lights, two outside receptacles, two receptacles for miscellaneous general use laptops.

I just saw they make split 20-amp breakers for one space. I thought they only used split 15-amp breakers.

stanfortyman
Nov 9, 2013, 05:59 AM
How many 15 and/or 20-amp receptacles are acceptable-- in general -on a 20 amp breaker?

How many 15 amp receptacles are acceptable on 15 amp breaker?As many as you want. Some people have set limits, but most professional electricians just use judgement according to what the circuit is feeding.
It's rare that I'd go over ten on an general use receptacle circuit.




I had new codes were going to do away with all 15 amp receptacles in near future.False! Where did you hear this one?




I have run 3 #6's and #8 ground 180 ft too 12 by 16 cabin, with 2-pole 50 amp breaker acting as my main, in a 6 space sub-panel. That leaves me four spaces.I don't like tiny little panels like that. No reason whatsoever to use them. Why not install a 12 space main breaker panel? By the time you bought the 60A breaker to act as a main you are probably close in price.
Did you get the required back-feed breaker hold down for the 60A main?




First space a I plan to be 20-amp dedicated mostly for window air conditioner.IMO a small window A/C does not need a dedicated circuit. You can have a few general use receptacles on with this.




2nd space dedicated for 2, 20 amp receptacles-- mini-fridge( 4-amps? ) and coffee maker( 9-amps? ) ---.OK. As long as you're sure you'll never have a toaster oven or microwave. Personally I'd have two separate circuits to the kitchen area, even though it is not a kitchen.





I just saw they make split 20-amp breakers for one space. I thought they only used split 15-amp breakers.
Again, completely false. Who are you getting all this misinformation from?
I bet your 6-space panel is a 6/12, meaning that you can use tandem breakers in every spot.

donf
Nov 9, 2013, 10:39 AM
Does your cabin have a Grounding system? If not, you need to set it up. You will need at least one (1) ground rod, possibly two.

Also, the Neutral buss and the grounding buss must be isolated at the cabin's panelboard.

rr6
Nov 9, 2013, 05:11 PM
stanfortyman;3
Did you get the required back-feed breaker hold down for the 60A main?

What is that back-feed thing? Is that like a lock out used on breaker to keep someone from turning it on while your at the other end doing something?



IMO a small window A/C does not need a dedicated circuit. You can have a few general use receptacles on with this.

Well it will be regular receptacle, I mispoke to call it dedicated, so as long as they know not to over load it.



Who are you getting all this misinformation from?
I bet your 6-space panel is a 6/12, meaning that you can use tandem breakers in every spot.

I forget where I heard about possible new code regarding no 15-amp receptacles coming.

Yes it is 6 space sub-panel--- $19. Sq. D/Homelite --- with two lugs, but I put in the 2-pole 50 amp breaker in two spaces as my main, so as to have shut off in cabin, as the the main may have strangers/renting living in the house with the main pane.

My next question is in regards grounding and ground wires.

I bought the extra little grounding bar with maybe 5 holes/screws and screwed it to panel and attached both the ground from the main panel and the ground to the ground rod outside of cabin.

What I notice is, that, the neutral bus bar has like 20 holes/screws, so I'm wondering, when I run a circuit, should I connect grounds to the tiny add-on grounding bus bar with its only 3 or 4 holes not used,

Or can I connect the grounds to the neutral bus bar being there is plenty of holes/screws available.


Thx for you reply.
The main panel I'm pulling off has the ground and neutrals on both grounding and neutral bar-- though I know new codes will not allow that ---,

So just wondering where to put the grounds for my circuits.

Thx

rr6
Nov 9, 2013, 05:16 PM
Does your cabin have a Grounding system? If not, you need to set it up. You will need at least one (1) ground rod, possibly two.
Also, the Neutral buss and the grounding buss must be isolated at the cabin's panelboard.

Hi Yes. I installed ground rod today, and ran #8 to it from the tiny additional gorund bar I bought and screwed into the panel.

I also attached the ground from main panel to this little gorunding bar.

My next question is in regards grounding and ground wires.

I bought the extra little grounding bar with maybe 5 holes/screws and screwed it to panel and attached both the ground from the main panel and the ground to the ground rod outside of cabin.

What I notice is, that, the neutral bus bar has like 20 holes/screws, so I'm wondering, when I run a circuit, should I connect grounds to the tiny add-on grounding bus bar with its only 3 or 4 holes not used,

Or can I connect the grounds to the neutral bus bar being there is plenty of holes/screws available.

And one last thing, this 6 space sub-panel came with a green screw about 1 or 1-1/2 long. The additional little grounding bar came with its on screw so 'im guessing the green one is just and extra at this point.

Thx for any help.

stanfortyman
Nov 9, 2013, 05:44 PM
The circuit grounds must be run to the ground bar you added to the panel. The neutrals must be connected to the neutral bar that is isolated from the panel box on the plastic standoffs.

When you use a branch circuit breaker to back-feed a panel you must install a breaker hold down retention device since the breaker can be pulled off the buss and it will remain live with voltage.

rr6
Nov 10, 2013, 05:04 AM
The circuit grounds must be run to the ground bar you added to the panel. The neutrals must be connected to the neutral bar that is isolated from the panel box on the plastic standoffs.

Ok, so that means I have should have bougth a larger grounding bar. The one I installed only had like 4-6 holes to begin with, and two of those are nowt occupied by #8 ground back to main panel. And #8 to ground rod.

I suppose since the circuits are only #12 I can maybe double or triple them, or go buy a differrent grounding bar or have 2 sperate grounding bars in the panel.


When you use a branch circuit breaker to back-feed a panel you must install a breaker hold down retention device since the breaker can be pulled off the buss and it will remain live with voltage.

So this "breaker hold down" goes on my 50-amp breaker in the sub-panel?

I would think the panels conver would keep the breaker from dissconnecting from the hot bus bars.

So this "breaker hold down" is not the same as a lock-out, that is used to keep someone from turning on the breaker when someone is working at the other end?

Thx.

stanfortyman
Nov 10, 2013, 05:23 AM
I suppose since the circuits are only #12 I can maybe double or triple them, or go buy a differrent grounding bar or have 2 sperate grounding bars in the panel. Yes. Yes. And yes. :)



So this "breaker hold down" goes on my 50-amp breaker in the sub-panel?

I would think the panels conver would keep the breaker from dissconnecting from the hot bus bars.

So this "breaker hold down" is not the same as a lock-out, that is used to keep someone from turning on the breaker when someone is working at the other end?The point is when the cover is removed the breaker can pop out by itself if worn or damaged, or that if you remove it the breaker is still live.

They are specific to each panel though.
https://www.google.com/search?q=breaker+retention+device&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a#q=breaker+hold+down&rls=org.mozilla:en-US%3Aofficial

The documentation that came with the panel should list one.

rr6
Nov 10, 2013, 05:41 AM
Y[QUOTE]es. Yes. And yes. :)

Ha ha, OK, I see get it now. Only run the circuit ground wires to grounding bar(s).

Why to they give 20-30 or more holes for the neutral bar that comes with panel? Seems excessive unless they were expecting both ground and neutrals attached there?

I know it is code these days, in the main, to keep grounds and neutrals on the sperate bars, even though the bars will be connected, but in my case, the main was done before that code/policey was emphasized i.e. my main has grounds and neutrals on both ground and neutral bar.

Even the steel nipple coming into the main has a grounding ring with that wire going to the neutral bar.


The point is when the cover is removed the breaker can pop out by itself if worn or damaged, or that if you remove it the breaker is still live.

The documentation that came with the panel should list one..

Aha! Ok that makes sense. I never heard of that but the cheaper the box design--- ex this Sq. D sub-P only cost $19. ---the more chance that could happen.

I will definitely check out your link. I hope I can install this "hold-down" on the 50-amp breaker I installed.

H,mmm had another question but slips my mind.

Thx again for your advice.


They are specific to each panel though.
https://www.google.com/search?q=breaker+retention+device&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a#q=breaker+hold+down&rls=org.mozilla:en-US%3Aofficial

rr6
Nov 10, 2013, 06:14 AM
Hi Stan-40, I did search for Square D 2-pole hold downs. They only make a right hand side hold down kit and I think that may not work for where my breaker is located on far right side. I don't know.

I probably have enough slack in wire to move it over a slot or two if I need to.. No biggie.

But the other question I remmembered, is that extral green screw that came with the sub-panel. Since I had the purchase ground bar separately and it came with its own attaching screw, the green screw is irrelevant extra screw.

Thx again about that 2-pole hold down kit, that popping out could be serious issue and I never heard of that.

rr6
Nov 10, 2013, 07:02 AM
[QUOTE=stanfortymanI bet your 6-space panel is a 6/12, meaning that you can use tandem breakers in every spot.[/QUOTE]

HI Stan 40, I finished reading all of the instructions for my panel, way after it is installed and I turned on power.. ha ha.

The state, that, it is OK to use tandem( split? ) breakers as long as the panel is only being used for single phase application. I have no 220 items planned nor any 220 with 2-phase motors.

So, I will probably do one or two split 15 or 20 amps, though in my case that is probably over what is needed.

I built a 7.5 by 12 camper/hut/cabin that she may park next to cabin and use as a bathroom so maybe a light and receptcle there, but will always remind myself and her, that were pulling off 100 amp panel so we really do not want to max out our sub-panel any more than necessary.

I've never tripped a main in any house. I did have the feeder neutral from meter corrode away the lug and I smelled electric burning so my more expereince electrican neighbor, at the time, came over and we cut the locking pin and yanked meter out of box.

I also used the antioxidixing stuff on my neutral wire, as another electrcian friend said he learned about that the hard way, in that he burned out of his electric appliances etc... so some years ago he learned to use that antioxidizing stuff.

Thank you thank you thank you again for the lock down for main feedback breakers

stanfortyman
Nov 10, 2013, 07:07 AM
Mine in red:

Ha ha, OK, I see get it now. Only run the circuit ground wires to grounding bar(s). Yes, ground wires.

Why to they give 20-30 or more holes for the neutral bar that comes with panel? Seems excessive unless they were expecting both ground and neutrals attached there? Mostly because if a panel is a main panel both neutrals and grounds go to the same bar(s), but also you can double or even triple ground wires in a hole, but neutrals must be one to a hole.

I know it is code these days, in the main, to keep grounds and neutrals on the sperate bars, even though the bars will be connected, but in my case, the main was done before that code/policey was emphasized i.e. my main has grounds and neutrals on both ground and neutral bar. It is not at all code to keep grounds and neutrals on separate bars in a main panel. What is true is that neutrals cannot be on added-on ground bars.

Even the steel nipple coming into the main has a grounding ring with that wire going to the neutral bar. See previous two comments.

rr6
Nov 10, 2013, 07:44 AM
Mine in red:

Only "one neutral to a hole". That is another code/policy I had not heard of.

You are full of good stuff. It is hard to believe that anyone would use this $19. Sub-panel as a main panel. I do see that the punchouts allow for 2" hole though.

And since it has the two lugs hot and neutral I guess it could be used as a main.

H,mmm seems I had another question but cannot recall it.

Thanks again for excellent advice.

Oh yeah, I did notice that mywhite #8 neutral seemed to be bigger in diameter than the hots/leads? I seemed to recall that in past with 12AWG etc.. but said no I was imagining stuff.

r6

rr6
Nov 10, 2013, 07:52 AM
[QUOTE=stanfortyman;3583277] It is not at all code to keep grounds and neutrals on separate bars in a main panel. What is true is that neutrals cannot be on added-on ground bars.

Ok I guess it was just that my state inspecter required I keep them separate when did main in my new house.

So, based on your advice, that, neutrals should not go on ground bus bar, then how much priority would you place on my going back to my main-- installed 20 years ago in old house and feeding this new sub-panel ---and moving my neutrals off ground bar and putting them on neutral bar?

stanfortyman
Nov 10, 2013, 10:50 AM
So, based on your advice, that, neutrals should not go on ground bus bar, then how much priority would you place on my going back to my main-- installed 20 years ago in old house and feeding this new sub-panel ---and moving my neutrals off ground bar and putting them on neutral bar?If there are neutrals actually on an add-on ground bar, screwed directly to the back of the panel box, I would definitely move them to a neutral bar.
The panel box itself cannot be a path for neutral current.

rr6
Nov 10, 2013, 11:18 AM
Stan40.."If there are neutrals actually on an add-on ground bar, screwed directly to the back of the panel box, I would definitely move them to a neutral bar.
The panel box itself cannot be a path for neutral current."

I was referring to the 100 amp main that I'm pulling off. That panel came with ground bar already installed, so I assume it is not a "add on" grounding bar.

At that time--- 20 years ago --- my electrician friend said it was OK to have ground wires and neutrals on ethier bar, since the two bars were connected.

I guess the concern is the the neutrals have the most direct path out to ground post on transformer, then to the Earth via cable on the pole, or wherever it goes to get to ground..

The 20 year old main service panel is 100 amp is Square D. It would probably take me and hour to reroute all of the neutrals from ground bar to neutral bar. Might have to make some wire nut connections if the wires were to short.

Again, the ground bar was already in the panel when I bought it new. That was my first service panel install ever. I was replaceing the fuse box that had the corroded neutral lug.

donf
Nov 10, 2013, 01:34 PM
Neutral and Ground can only meet at the main service panelboard. No where else in the system.

At thr rtemote panelboard, Neutral and Ground must be isolated from each other.

rr6
Nov 10, 2013, 03:03 PM
Neutral and Ground can only meet at the main service panelboard. No where else in the system. At thr rtemote panelboard, Neutral and Ground must be isolated from each other.

Thanks don, I got and understood that info a few emails back.

My most recent question to stan40 was in regards my 100 amp main panel--- installed 20 years agon --- having some neutrals on the grounding bar.

I replied to him that, the grounding bar came with already installed i.e. it is not an add-on grounding bar that I added.

In my new home the stated inspector would no allow me to do that.
My question to Stan was how important is it for my 20 year old, 100 amp panel--- that I'm pulling off --for me to move those neutrals from ground bar and put them onto the neutral bar?

I guess it may come down to whether that ground bar has somekind of backing on it that keeps it from touching the service panel box. I do recall seeing that backing behind some bars some where some time ago, can't recall the exact details.

Thanks

Thanks

stanfortyman
Nov 10, 2013, 05:49 PM
If that ground bar is screwed right to the back of the panel box it is a bar for grounds only.

rr6
Nov 11, 2013, 05:12 AM
If that ground bar is screwed right to the back of the panel box it is a bar for grounds only.


Ok Stan40, thanks. I will go back into that main box and see iif ground bar is in direct contact with panel or if there is some kind of paper(?) backing behind it.

I guess the neutrals are required to be only on neutral bar--- even to it is connected to ground bar ---because neutral and incoming neutral wire is most direct feed to ground wherever that may be.

I thought it was the cable on pole going to Earth from outside of transformer. I don't know. Thx again for your knowledge expertise.

I did not glue L junction box at each end of long run, under house and cabin, not did I glue the 2" to 1-1/4" reducer, not the 1-1/4" flex conduit into those reducers.

They are held tight via junction box(es) are sitting on board on ground and1-1/4 conduit attached to panel(s). Today I will tape the areas where flex pipe meets junction box(es), then I will put cinder blocks to block junction box from sliding off, and I will put rebar stakes on either side of conduit to keep it from lateral movement side-to-side.

Will maybe used L shaped rebar so it helps prevent vertical movement of conduit also though the flex pipe should prevent that as it stiff run vertical to panel(s).

Once I had wire run to get correct length to cut off, and to see if I could get it through that last section, I did not want to pull it all apart just to glue those connection areas.

I even thought of wrapping the area first with some kind of rommex like vinyle then wrapping with electrical tape.

Thanks again

rr6
Nov 22, 2013, 11:59 AM
Hi Stan-40, I finally got back into the 100 amp main panel I'm pulling off for my 2-pole 50-amp feebdack main.

In this 20 year old Square D box, the ground bus bar is isolated from the metal box by plastic. So I will leave my on the few neutrals that are there. I guess.

I forgot to check and see if there is only 1 neural per hole on the neutral bar, from 20 years ago when I installed it. Probably is since I have not used on the breaker slots.

I go the retaining g clip installed on the 2-pole feed-back main in the sub-panel. Thx again for that excellent tip!

Another question if your still here, is the leads and neutral to sub-panel are #6 and I ran a #8 ground wire to the ground rod outside cabin for the sub-panel.

Seems I recall two suggestions elswhere in my readings;

1) I should use as large or larger than the leads, ground wire to the ground rod,

2) I should have installed two ground rods?

I put the ground rod in on 8 or 10ft ground rod in on a 45 degree slant and was short if getting it all the way in by about 2 or 2.5 ft.

Also I installed the rod so that its actually under the house, so it may get less moisture from rain fall ergo less good grounding.

Thx for any advice.

If there are neutrals actually on an add-on ground bar, screwed directly to the back of the panel box, I would definitely move them to a neutral bar.
The panel box itself cannot be a path for neutral current.

rr6
Nov 22, 2013, 12:01 PM
Hi Stan-40, I finally got back into the 100 amp main panel I'm pulling off for my 2-pole 50-amp feebdack main.

In this 20 year old Square D box, the ground bus bar is isolated from the metal box by plastic. So I will leave my on the few neutrals that are there. I guess.

I forgot to check and see if there is only 1 neural per hole on the neutral bar, from 20 years ago when I installed it. Probably is since I have not used on the breaker slots.

I go the retaining g clip installed on the 2-pole feed-back main in the sub-panel. Thx again for that excellent tip!

Another question if your still here, is the leads and neutral to sub-panel are #6 and I ran a #8 ground wire to the ground rod outside cabin for the sub-panel.

Seems I recall two suggestions elswhere in my readings;

1) I should use as large or larger than the leads, ground wire to the ground rod,

2) I should have installed two ground rods?

I put the ground rod in on 8 or 10ft in on a 45 degree slant and was short if getting it all the way in by about 2 or 2.5 ft.

Also I installed the rod so that its actually in ground under the cabin, so it may get less moisture from rain fall ergo less good grounding.

Thx for any advice. Next I figure reepticles, wiring lighting.

If there are neutrals actually on an add-on ground bar, screwed directly to the back of the panel box, I would definitely move them to a neutral bar.
The panel box itself cannot be a path for neutral current.