Future space in panels

[electricelmo]

Is there a code that referes to future spaces in panels we have run across basement finishes of homes that the panel is completely full, i have been told there was a code that reguired 10% open spaces in residental panels for future finishing of basement or future equipment? I sure can not find the code

 

[charlie b]

No such code rule exists. It is a good design idea to leave spares, but not a requirement.

 

[cpal]

This is one of the only places that I can think of . But!!

The document is not a design manual and this language is a suggestion( it does not use the pharase "shall"). IMO It probably should be a FPN.

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 the use of electricity. 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.

 

[celtic]

Before one gets to 90.8, they should first come across:

90.1 Scope
B) Adequacy.
This Code contains provisions that are considered necessary for safety. Compliance therewith and proper maintenance will result in an installation that is essentially free from hazard but not necessarily efficient, convenient, or adequate for good service or future expansion of electrical use.

 

[mark henderson]

Back when I was a helper the owner of the company always told me it was code to leave 2 spaces for future use. I still have not been able to find that code. I believe it was his own preference and a good idea for the next guy.

Mark

 

[cpal]

Agreed
But as Celtic and I posted, neither the scope of the Article 90, which is titled as neither introduction, nor 90.8 in my post contains mandatory language to force the issue of allowance for future use. The NEC is a minimum standard. Fortunately many such as your self do make provisions wither by design or professional experience

 

[Jljohnson]

I work for a GC that I have finally trained to take a digital photo of the existing load center and bring it to me with the plans when he requests a quote. Tis way there are no surprises at rough-in time with scope of work or cost increases to add a sub-panel.

 

[LarryFine]

I think that the application also comes into play when deciding this. For example, if we're wiring an apartment or townhouse, where it's a sure bet that no new circuits will ever be added, I'll max out a panel with no hesitation.

At most, the capability of having spaces that will accept tandem breakers for future additions would satisfy me, unless additional space is specified in the job, or, say, a house with a basement that is ripe for future finishing.

 

[Dennis Alwon]

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 the use of electricity. 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.

IMO, if the service provided allows for expansion then you have meet this rule. Now I don't disagree that it is a good idea to leave spaces but as long as one could add a sub panel later by moving a few circuits I don't see why that isn't considered room for expansion.

 

[celtic]

For example, if we're wiring an apartment or townhouse, where it's a sure bet that no new circuits will ever be added, I'll max out a panel with no hesitation.

".....no new circuits will ever be added...."
That's a heavy statement!

I wonder what ECs thought 80 years ago when they had 1 circuit for an entire apartment ".....no new circuits will ever be added...."...then came TVs, Irons, a TV/VCR/DVD/Cable box in every room, computers/printers/modems all over the place...etc.

At most, the capability of having spaces that will accept tandem breakers for future additions would satisfy me, unless additional space is specified in the job, or, say, a house with a basement that is ripe for future finishing.

Thanks God (not that the manufac's are Gods ) for tandems, eh?