# Generator clearances



## Jlarson

Sounds like you are good to go with the Generac unit IMO.


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## Ima Hack

I'd CYA and verify with code enforcement. 

We had to move one a couple of years ago because we were 4'-10" from the building. The generator was a 50kW Onan. What a bummer that was.

Inspector would not budge.


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## Jlarson

Ima Hack said:


> I'd CYA and verify with code enforcement.
> 
> We had to move one a couple of years ago because we were 4'-10" from the building. The generator was a 50kW Onan. What a bummer that was.
> 
> Inspector would not budge.


I would have built a block wall in between the genny and house, I say a man made block wall qualifies as a structure...


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## Ima Hack

Jlarson said:


> I would have built a block wall in between the genny and house, I say a man made block wall qualifies as a structure...


That was considered, but the entire wall has to be non-combustible. Plus this was a commercial job and the building was like 90' long.


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## Jlarson

Ima Hack said:


> That was considered, but the entire wall has to be non-combustible. Plus this was a commercial job and the building was like 90' long.


Aw damn, then plan C would be launched, I would build a generator room w/ all the trimmings before I moved a 50kW. I work on one like that, actually it's a 50 kW Onan if I recall correctly.


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## HARRY304E

Jlarson said:


> Aw damn, then plan C would be launched, I would build a generator room w/ all the trimmings before I moved a 50kW. I work on one like that, actually it's a 50 kW Onan if I recall correctly.


I agree:thumbup:


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## ColoradoMaster3768

What Code set is the AHJ enforcing? You may want to run it by them first. Maybe they'll offer an economical solution.


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## Shorty Circuit

kbsparky said:


> I am currently preparing a quote for a customer to provide and install a standby generator system. I have discovered that in most cases, a generator set placed outside has to maintain a minimum clearance of five feet from the building, if it is constructed of combustible materials.
> 
> This particular customer has a 4½ foot swath of space between the side of his garage and a brick-paver walkway. His outside condenser unit is located within this space, and he would like the new generator to be similarly located there.
> 
> Here is the section of the NFPA requiring the 5 foot clearance:
> 
> 
> Based on this standard, many manufacturers require that the 5 foot clearance space be maintained on the installation of their units.
> 
> _Generac_, however, allows for an 18" clearance. Here is the text from their installation manual for a residential 14 kW unit:
> 
> So it would seem that I can install the unit in that 4½ foot swath of available space if I specify and use a _Generac_ unit.
> 
> The question I have is have any of you had to deal with this issue, and are there any other manufacturers that have tested their units to deal with the requirements of NFPA 37 4.1.4?
> 
> 
> Edit to add: Here is a link of a formal interpretation of NFPA 37, 4.1.4


 
Apply for a variance. The building department might allow it because their intepretation may be that it meets the intent of the code if not the letter of it. Besides, in a additon to their permit and inspection fee, won't this raise the owner's real estate taxes? There's their incentive. You have nothing to lose by trying.


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## kbsparky

There are no building permits for this type of installation in this area.

Only an electrical permit and inspection are required.

The section of the Code that would apply here is 110.3(B) -- which refers to the manufacturer's instructions. Since the manufacturer has stated that the unit can be mounted with a clearance of 18 inches, then no variance is needed.

THE PROBLEM here is the _other manufacturers _ (e.g. competitors of Generac) have cried foul, stating that their testing was bogus. Seems that it was not UL who did the testing, but another agency. I am trying to ascertain who exactly did the testing, and are they a nationally recognized testing/listing service?

With the problems associated with Generac discussed elsewhere on this forum,  I wanted to hear if this was an issue for anyone on generator installations.


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## bcramer

KB, Generac has gone through extensive fire testing on its air-cooled units. I am not aware of any other manufacturer performing the same tests to date. There was a competitor at the NFPA conference to listen the testing procedure presentation. The 18 inches is for the air-cooled product not liquid cooled. The distance is 18 inches from a combustible wall but like other posts, confirm with local code enforcement before any install. It is not uncommon for NFPA 37 to be misunderstood as some inspectors are not aware of the formal interpretation.


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## ColoradoMaster3768

kbsparky said:


> There are no building permits for this type of installation in this area.





kbsparky said:


> Only an electrical permit and inspection are required.
> 
> The section of the Code that would apply here is 110.3(B) -- which refers to the manufacturer's instructions. Since the manufacturer has stated that the unit can be mounted with a clearance of 18 inches, then no variance is needed.
> 
> THE PROBLEM here is the _other manufacturers _(e.g. competitors of Generac) have cried foul, stating that their testing was bogus. Seems that it was not UL who did the testing, but another agency. I am trying to ascertain who exactly did the testing, and are they a nationally recognized testing/listing service?
> 
> With the problems associated with Generac discussed elsewhere on this forum, I wanted to hear if this was an issue for anyone on generator installations.


Sounds like politics to me, and that usually speaks to a "no win" situation. 

The NEC defines "labeled" as: Equipment or materials to which has been attached a label, symbol, or other identifying mark of an organization that is _acceptable to the authority having jurisdiction and concerned with product evaluation, _that maintains periodic inspection of production of labeled equipment or materials, and by whose labeling the manufacturer indicates compliance with appropriate standards or performance in a specified manner. [_emphasis mine_] 

And, "listed" as: Equipment, materials, or services included in a list published by an organization that is acceptable to the authority having jurisdiction and concerned with evaluation of products or services, that maintains periodic inspection of production of listed equipment or materials or periodic evaluation of services, and whose listing states that either the equipment, material, or service meets appropriate designated standards or has been tested and found suitable for a specified purpose. 
Informational Note: The means for identifying listed equipment may vary for each organization concerned with product evaluation, some of which do not recognize equipment as listed unless it is also labeled. Use of the system employed by the listing organization allows the authority having jurisdiction to identify a listed product.

From these definitions it is clear that _listed_does not equal _labeled_, irrespective of what competing might manufacturers' argue. 

110.3 (B) *Installation and Use* states, "Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling." 

As I understand "the King's English" the unit can be _listed _*or *_labeled, _it does not have to be both. Therefore, if your AHJ finds the proposed installation and use in accordance with the manufacturer's labeling (or marketable intent), then by _Code, _they have the authority to "bless" the installation. I would suggest you run your cut-sheets by the AHJ to see if you can get their blessing (in writing of course).


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## George spader

What about the distance between generator and ac compressor out side


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## just the cowboy

George spader said:


> What about the distance between generator and ac compressor out side


Repost in a new thread this one is 11 years old. You will get better answers, this is what is called a zombie thread it may come back to life and then again it may not. 
welcome
Cowboy


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