sub panels (again) and question on mixed wiring

Reply

  #1  
Old 02-18-13, 06:33 PM
Member
Thread Starter
Join Date: Feb 2013
Location: USA
Posts: 4
sub panels (again) and question on mixed wiring

Pretty sure I know the answers to the questions but I did find some mixed signals, both on the internet and the "real world".
First question is in regards to sub panel "free space". I'm thinking about adding a 90A sub panel to an existing 100A main panel. Code requires 30" clearance L/R and 36" clearance in front. I'd prefer to put the panel in the furnace room where the main panel is. L/R clearance is no problem.. but the 36" in front is annoyingly 1" (35" from face to furnace base) short if you measure from the floor to where the furnace is. At face level, due to the sloping duct work there is plenty of clearance. Now somewhere I heard that the "space box" can be 30/30 in existing structures..(????) Barring a complete no go I do have an alternate location which is a laundry room. Again L/R no issues. but the room is only 6' deep. Depending on the size of a washer/dryer (and plumbing electrical setback of the equipment) that 36" will be variable and may or may not be exactly 36". Also there is some concern w/ putting the panel in a "wet room".. So any advice? (after this is answered I will probably have a few more re:this panel)

Second this site is the first I've seen that has mention of a ground rod for sub panels but most seem to be in regards to secondary or out buildings. Clarity would be appreciated.

Third the house has a bathroom circuit which apparently is all 12ga except for the ceiling fan/light circuit which has 14ga feeding it. Currently it is OK (relatively speaking) because the circuit is fed by 14ga and a 15A breaker. Is a 12ga/20a feed possible w/out replacing the fan/light feed? Fun wiring huh. I do understand it may not be the best but the fixture is new w/ a fluorescent bulb and a smallish fan (does that make any difference?) and would not likely ever be changed to anything more electrically demanding (I realize this is NOT usually a consideration)..


House was put together in the 60's (longish story since to was a moved railroad station w/ and addition added on)
 
Sponsored Links
  #2  
Old 02-18-13, 07:25 PM
Nashkat1's Avatar
Member
Join Date: Mar 2012
Location: USA
Posts: 8,470
Welcome to the forums!

The free space requirement is what it is. It is especially critical at floor level, to avoid a trip hazard within the work space. Did you drop a plumb mark off the face of the panel and measure from that?

There is no prohibition on having a panel in a laundry room in the NEC. A laundry room is not considered a wet location in that model code, so ordinary indoor-rated electrical equipment is allowed to be there, unless your local jurisdiction has ruled otherwise. Ask them.

the house has a bathroom circuit which apparently is all 12ga except for the ceiling fan/light circuit which has 14ga feeding it.
Are you talking about one circuit or two?

a bathroom circuit which apparently is all 12ga except... the circuit is fed by 14ga and a 15A breaker.
Are you saying that there is a circuit that is protected by a 15A breaker and that leaves the distribution panel through #14 AWG conductors, and that there is some #12 AWG wire in the circuit downstream? If so, there's nothing wrong with that.

the house has a bathroom circuit which... is fed by 14ga and a 15A breaker
There should be a GFCI protected receptacle in the bathroom. That needs to be fed by a 20A circuit which can also be used to supply the lighting in that bathroom only.

Is a 12ga/20a feed possible w/out replacing the fan/light feed?
Are you asking about the fan's internal wiring, which is almost certainly smaller than #14 AWG, or are you asking about some wiring in the walls or ceiling on the way to the fan?
 
  #3  
Old 02-18-13, 10:23 PM
Member
Thread Starter
Join Date: Feb 2013
Location: USA
Posts: 4
Measured from the face of the wall studs.. (unfinished wall) since the panel(flush mount) is not installed and if it was close (i.e. closer than a full inch) I would have been more accurate..
Seems the laundry room is the correct option, though from a working/practical standpoint the furnace room 3ft from the main panel (and the sub panel cutoff) would seem more practical.. but rules are rules .. for a reason.
Now could I recess the box into the stud wall by cutting back the 2x4 by an inch in that area??? (I'm not going to do it but I assume the code is from face out (not from circuits inside out correct? In other words EXACTLY where does one measure back from? panel face? nearest point of breaker? Internal wiring, after all most boxes have the actual working bits recessed inside. )

As to the bathroom wiring, yes there is one 14ga feed line).. it looks to be all protected by a 15a gfci (w/ the exception of the ceiling fan/light combo) since the main breaker on that circuit was a 15A (2 outlets and a light over the vanity. ) but the ceiling light and fan combo (away from the tub and sink) are not on the "daisy chain" from the gfi. The in wall feeders to the light are 14ga. I'm not even considering the in-fixture wiring. I guess the point is esoteric re: how you could "overheat" a branch circuit connected to the main line by using this set up. This is a bit beside code and more of an "why" discussion on this point.


to clarify a bit on the wiring... 14ga/15a breaker (currently) runs from the main panel to a junction box. From there it is attached to 12ga going into the wall and down to a outlet (GFCI) feeding (and protecting) a branch circuit of 1 outlet and an over the vanity light. All of that wiring is 12ga.. the only 14ga at this point is the 2 feeder lines (not gfci protected) going back up the wall to the ceiling fan light combo.

My current options seem to be 1)leaving the existing wiring (ignoring the fact that any 12ga exists) and treating it as a 15a line with all (but the ceiling unit) protected w/ the 15a GFCI. (do no harm syndrome)

2)replacing the fan wiring, feeder line w/ 12ga (20A circuit) and figuring out how to get the ceiling light on a now replaced 20A GFI (which seems to involve going to the end of the line, bringing it up and back across back to the entry way switches and dropping it back down to run the lights (since AFAIKT) you can't run branches off a GFCI (is that correct?)
Seems like a ceiling light/fan far enough away from the tub is an "exception" to GFCI protection??
1. 210.11(C)(3) - This sections calls for at least one 20A branch circuit to supply bathroom receptacle outlets and NO OTHER OUTLETS.
2. 210.11(C) Exception - This exception states where the 20A circuit supplies a single bathroom, other outlets in that same bathroom can be supplied IF you comply 210.23
3. 210.23(A) - This section states that 20A branch circuits are permitted to supply a combination of outlets such as lighting and receptacle outlets, EXCEPT...
4. 210.23(A) Exception - This exception states the 20A branch circuit to bathrooms as required in 210.11(C) may only supply receptacle outlets.
So here's the loop. Can the bathroom branch circuit also supply the lights and exhaust fan?

210.11(C)(3) says NO.
210.11(C) exception says YES, but...
210.23(A) says YES.
210.23(A) exception says NO, see 210.11(C)
How does anything get done..


I'd give the orig installer a E for effort though underrated by current code..

To sum it up the absolute correct way would be to replace the 2 14ga feed wires to the light/fan w/ 12ga. Run a new 12ga line from the junction box back to the main panel (after these 2 things there would be zero 14ga anywhere in the bathroom) and then figure out IF the fan/light combo needs to be on the GFCI or not.

My real point of clarity is 1)Is the 14ga feeder to the lights (as is) a hazard IF that wire is not upgraded to 12ga but the feed wire/breaker is?
2) does that light/fan NEED to be on a GFCI (and does distance from the tub matter (sorry haven't measured it yet but it is at least 3' from the toilet sink and possibly 3' from the back of the tub)??

I'm probably making this more complicated than it needs to be..
 
  #4  
Old 02-19-13, 05:32 AM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 14,365
A ground rod would not be required in your situation.

If I were an inspector I would probably let the 1" shortage go seeing how you are working with existing conditions and are so close. However, I am not signing off on your permit. You should call your inspector for their view.

The #14 should not be protected by a 20 amp breaker.

The fan/light does not require GFI protection unless over a tub or shower.
 
  #5  
Old 02-19-13, 06:21 AM
Member
Thread Starter
Join Date: Feb 2013
Location: USA
Posts: 4
pcboss a "practical" take on the issue.. As to the #14 are you referring to the scenario of all the wiring #12 except the line from the switch to the ceiling light/fan combo?? or w/ the feeder at #14 as well. The run is 8' from switch to fixture.. A silly alternative would be #12 to the box but a 15A breaker, a 20A GFCI (since it's load is ALL #12, though this is not really much of a necessity since the main breaker is 15A) and leaving the light feed at #14)

I guess my separating of an outlet "potential" (who knows what one would plug in) and the "potential draw" over the #14 fan/light combo leads me looking at "in theory" the #14 is "safe" from overheating since it is not in line w/ the receptacles. Short of a dead short or ripping out the current low draw ceiling light circuit and replacing it w/ an outlet it would not, in theory pull a 20A draw.
I wouldn't even be thinking on this line except for the difficulty of the lamp placement and feed wire replacement..thus the point where physics meets code..

As I said leaving it "as is" wired w/ the assumption no #12 exists in the circuit is/was acceptable in a discussable way, not a personality of inspector way.

The wonderful thing about codes is relieves one of always contemplating theory and reality..
 
  #6  
Old 02-19-13, 12:36 PM
Nashkat1's Avatar
Member
Join Date: Mar 2012
Location: USA
Posts: 8,470
could I recess the box into the stud wall by cutting back the 2x4 by an inch in that area?
Sure, if you did that for the entire 30" wide floor-to-ceiling area. Easier to just reframe the area with 2X3s, probably.

Of course, if you did that, your panel would no longer sit flush. They're made to be recessed into 2X4 framing. Just ask your inspector before you do it, as PCboss suggests. Asking after the fact is frowned on.

1)Is the 14ga feeder to the lights (as is) a hazard IF that wire is not upgraded to 12ga but the feed wire/breaker is?
Yes.

2) does that light/fan NEED to be on a GFCI
No. The light over the vanity and its switch do not either. In addition, you should not need to install a 20A GFCI receptacle. Your existing 15A device should be rated for 20A pass through.

does distance from the tub matter (sorry haven't measured it yet but it is at least 3' from the toilet sink and possibly 3' from the back of the tub)??
The fan should not be over the footprint of the tub. Distance from the back of the tub doesn't matter. All switches need to be 6' or more - IIRC - from the nearest edge of the tub.

I'm probably making this more complicated than it needs to be..
Probably. I don't know where you got that quote - sounds like chatter from a partially informed forum - but it's funny. Thanks for the grin.
 
  #7  
Old 02-19-13, 05:45 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,221
1)Is the 14ga feeder to the lights (as is) a hazard IF that wire is not upgraded to 12ga but the feed wire/breaker is?
I just want to point out that 30 years ago this was a very common way of wiring a switchleg on a 20 amp lighting circuit. If it weren't for the fact you are reworking the entire bathroom, I'd probably just leave it as is. Since you are reworking everything, I think I'd either replace the 14 gauge with 12 gauge or replace the breaker with a 15 amp breaker. That being said, if this circuit also powers a bathroom receptacle, current code requires it be a 20 amp circuit.
 
  #8  
Old 02-21-13, 12:08 PM
Member
Thread Starter
Join Date: Feb 2013
Location: USA
Posts: 4
Cutting into the wall is not much of a problem.. getting to the light/fan junction box is the major problem..

As to rewiring the whole thing.. all the wire is already in place from someone elses mess..

job would be REAL easy if all I had to do is run a new 12ga line from the box to the junction box feeding the previously mentioned mess and replacing any mismatched things like GFCI and non-20a outlets... As to the GFCI it is already upstream of everything.. but the ceiling fan/light which is in the middle of the room not above any wet things..

Oh well easy and code does not always go hand in hand.. Won't get back to "the project" till this weekend.. Enjoy
 
  #9  
Old 02-21-13, 01:21 PM
Nashkat1's Avatar
Member
Join Date: Mar 2012
Location: USA
Posts: 8,470
job would be REAL easy if all I had to do is run a new 12ga line from the box to the junction box feeding the previously mentioned mess
Isn't that all you have to do? Other than replacing the cable going to the ceiling fan/light, of course.

replacing any mismatched things like GFCI and non-20a outlets...
Originally Posted by Nashkat1
you should not need to install a 20A GFCI receptacle. Your existing 15A device should be rated for 20A pass through.
The same is true for your standard receptacles. You only need to install a 20 amp receptacle if you're going to plug a 20 amp load into it.

As to the GFCI it is already upstream of everything..
The feeds for the lights and fan can be connected to the LINE terminals on the GFCI, next to the wires feeding power in. Splice and pigtail them if you need to. Only the feed for the second receptacle should be connected to the LOAD terminals on the GFCI.
 
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
'