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#70963 - 10/17/06 09:34 PM Old panel box as splice box  
sprynda  Offline
Junior Member
Joined: Aug 2006
Posts: 11
Cresco, pa usa
Hello to all,
I have to upgrade a old Push O Matic 100 amp panel to a new 200 amp service. I need to relocate the panel to a new location due to clearace problems. Can I use the old panel box as a splice box
Thanks
sam


Work Gear for Electricians and the Trades

#70964 - 10/17/06 10:08 PM Re: Old panel box as splice box  
bot540  Offline
Member
Joined: Sep 2004
Posts: 174
Vernon Hills, IL
Yes, I recommend you gut the panel and screw the cover shut to make the splices not readily acessible.


Jesus may have been a capenter,but God was an electrician.Genesis1:3

#70965 - 10/18/06 03:10 AM Re: Old panel box as splice box  
e57  Offline
Member
Joined: May 2003
Posts: 2,876
S.F.,CA USA
Not sure if push-matic had door style covers to screw shut.... Or some didn't? Havent seen many in some time... But yes it can be done although not the neatest option, but certainly easier than moving everything into a sizable j-box. Just watch your de-rating (310.15) while refeeding it all.


Mark Heller
"Well - I oughta....." -Jackie Gleason

#70966 - 10/18/06 06:30 AM Re: Old panel box as splice box  
sprynda  Offline
Junior Member
Joined: Aug 2006
Posts: 11
Cresco, pa usa
Thanks for the info. It does have a standard door on it but i would need to put a screw in it to keep it locked. I got a punch of 4 in squares ready to go and one 6 x 6 for the range and dryer. i agree it would look nicer if i mount the j boxes as high as i can then that would free up wll space for the homeowner. however, in this home neatness is not a problem
sam


#70967 - 10/18/06 09:57 AM Re: Old panel box as splice box  
Almost Fried  Offline
Member
Joined: Sep 2006
Posts: 98
Madison County, Ark. USA
Sprynda. I do it often. As e57 says, watch your derating. I usually cut a piece of galvanized sheet 2 inches bigger each way, use the old cover as a hole template, then they can paint it to dissappear. You then don't have to use all those j boxes an the job finishes neater. Look down a page or two for this topic discussed a few weeks ago in more detail. Look here https://www.electrical-contractor.net/ubb/Forum1/HTML/007446.html I hope this link works, anyone know how to link back to previous post in a simpler manner?

[This message has been edited by Almost Fried (edited 10-18-2006).]


#70968 - 10/18/06 12:47 PM Re: Old panel box as splice box  
JJM  Offline
Member
Joined: Oct 2005
Posts: 100
A gutter is so much nicer, neater, and workmanlike... and you'll never get dirty looks from an inspector. You could even get a very large gang box. Besides, removing the cables from the old panel is not the difficult, and with a 100A panel, how many can we be talking about???

Joe


#70969 - 10/18/06 08:40 PM Re: Old panel box as splice box  
e57  Offline
Member
Joined: May 2003
Posts: 2,876
S.F.,CA USA
With a gutter... this would be a great time to discuss Annex B, Table B.310.11 [Linked Image] And load diversity after 30 current carrying in a gutter.... (15 2-wire, 10 unbalanced 3-wire, or combinations of the two.)


Mark Heller
"Well - I oughta....." -Jackie Gleason

#70970 - 10/19/06 12:22 AM Re: Old panel box as splice box  
JJM  Offline
Member
Joined: Oct 2005
Posts: 100
I could be WAY wrong here, isn't Table B 310.11 more a NFPA requirement than actual NEC code requirement? Was it ever actually adopted into code? (You can blast me because we're still using the 2002 NEC.) Moreoever, doesn't it only apply to feeders #8 or larger?

I can understand the issue here would be heat. However, heat would be an issue in a gutted out panel too? For that matter, heat is an issue in a panel in and of itself. GFCI and especially AFCI breakers generate LOTS of heat... no mention of that anywhere, and in my opinion THAT IS an issue. I always keep Raytec ST-60 infrared thermometer handy and I never noticed any real heat source from a gutter, J-box, service disconnect, or the meter. But point that thing at a panel loaded with GFCI and AFCI breakers and the results are pretty scary to me. On panels with a main, the main is ice cold, but the breakers are almost hot to the touch. Clamp your meter on figuring the breaker is almost at it's trip point, then you're shocked (no pun) it's only drawing 2A.

Heat would also be an issue with large gang boxes and dimmers. Something this section doesn't appear to address either. Of course, heat problems by upsizing wiring end to end. Then good luck with trying to trim out #10 or #8 for a 20A circuit.

I believe gutter fill is far more important of an issue, as addressed in NEC 376.22, but even that section has some oddball provisons.

By the way, heat and derating would also appear to be an issue in some of the panels we so proudly display here, with the conductors all neatly wire-tied together... something I too am guilty of.

From a practical standpoint, here in NYC gutters (and large J-boxes) are used all the time for service upgrades (when new panels need to be moved for space considerations, etc.) and I don't think I've ever seen any of them get red tagged.

Just my 2ยข of venting...

Joe


#70971 - 10/19/06 03:04 AM Re: Old panel box as splice box  
e57  Offline
Member
Joined: May 2003
Posts: 2,876
S.F.,CA USA
Only reason I brought it up is that on a 24 circuit panel, it could be very easy to over-fill a gutter, in terms of de-rating. 24 2-wires would be 48, 24 unbalanced 3-wire would be 36. With 30 being the trigger for de-rating the conductors in the gutter. Down to 40%!

FYI I'm in the process of installing one over two panels right now as a transition from NM above to a few surface panels... Which is why I have it on mind....

Anyway, yes you are right 'not part of the code'...
Quote
This annex is not a part of the requirements of this NFPA document but is included for informational purposes only.


And this is something I wish was made more clear about this code in particular. This is from commentary, also not code, but I'm using it as an example.

Quote
The factors in the second column of Table 310.15(B)(2)(a) are based on no diversity, meaning that all conductors in the raceway or cable are loaded to their maximum rated load. For load diversity, the user is directed to Annex B.


So, 'for load diversity, the user is directed outside the code? To an area that would allow you to have additional conductors in a more sensable way, and lays that out very easily in Table B.310.11. But by doing so, put that out of reach without Engineering Supervision. It would great if that one table were made more accessable. It would certainly make things like this easier.....


Mark Heller
"Well - I oughta....." -Jackie Gleason

#70972 - 10/19/06 04:37 AM Re: Old panel box as splice box  
iwire  Offline
Moderator
Joined: Jan 2003
Posts: 4,391
North Attleboro, MA USA
A few things about B.310.11.

In general under the NEC we can not use B.310.11 unless we are engineers.

310.15(A) tells us we have to either follow 310.15(B) or 310.15(C)

310.15(B) requires we use Tables 310.16 through Table 310.19 and Ampacity Table 310.20 through 310.23 as modified by (1) through (6).

310.15(C)Allows us to use engineering supervision which is the only way under the NEC to use Table B.310.11.

I say under the NEC as for us here in MA we do use Table B.310.11 all the time without even knowing it.

The MA amendments modify 310.15(B)(2)(a) into B.310.11. [Linked Image]


Bob Badger
Construction & Maintenance Electrician
Massachusetts

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