# NEC Required "future" spaces left in new panelboards



## RePhase277 (Feb 5, 2008)

That's Canada.


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## ralpha494 (Oct 29, 2008)

Der idn't one. Sorry I dot a code. 90.8 A & B


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## HARRY304E (Sep 15, 2010)

Shorty Circuit said:


> Where is the NEC reference for the number of unused spare spaces that must be left for future use in new panels? I recall it being 20% but I can't seem to find it.
> 
> Thanks in advance.


That is not required by the NEC.
2011 NEC.
90.8 Wiring Planning.
(A) Future Expansion and Convenience. Plans and specifications
that provide ample space in raceways, spare raceways,
and additional spaces allow for future increases in electric
power and communications circuits. Distribution centers located
in readily accessible locations provide convenience and
safety of operation.
(B) Number of Circuits in Enclosures. It is elsewhere provided
in this Code that the number of wires and circuits confined
in a single enclosure be varyingly restricted. Limiting the
number of circuits in a single enclosure minimizes the effects
from a short circuit or ground fault in one circuit.


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## Celtic (Nov 19, 2007)

NJ does not have any such requirement.


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## Jlarson (Jun 28, 2009)

InPhase277 said:


> That's Canada.


I love when people say you need to leave 2 open spaces. I come back with, "watch a lot of Holmes on Homes don't you?" :laughing:


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## sbrn33 (Mar 15, 2007)

Good rule of thumb though. 
This would be a much better code than a lot of the ones introduced in the last couple cycles.


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## aftershockews (Dec 22, 2012)

An 8/16 panel on a 200 amp circuit. All slimed out.:thumbup:


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## wildleg (Apr 12, 2009)

Shorty Circuit said:


> Where is the NEC reference for the number of unused spare spaces that must be left for future use in new panels? I recall it being 20% but I can't seem to find it.
> 
> Thanks in advance.


What code cycle was that ?


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## drspec (Sep 29, 2012)

Im working on an addition right now where the existing panel is a GE 20/40 circuit. This thing is PACKED with slim breakers. 40 of those bad boys slammed in there. But right outside is a 200 amp meter main with feed thru lugs. Not one single breaker there.


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## cultch (Aug 2, 2011)

One of our lighting panels at this High School we're doing is a 42 circuit panel with 8 circuits being used. 3 of those are the tvss. Brand new panel it's got (1) 3/4 that leaves the room!


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