Some one asked me a question about when you install a roof top HVAC system and there are weatherproof receptacles installed within 25' of the unit. Say this install is on a large commercial building. The first unit from tenant A is next to tenant B's unit. Tenant A has a WP recpt. within 25'all is OK. Does tenant B need a receptacle within 25'? Will tenant A's fullfill the requirement?

Harold:
Yes, 'B' will need one. IF tenent 'A' becomes vacant, with power terminated, then there is no receptacle available. Also, 'A' may not appreciate 'Bs' use of their power, although it is minimal at best guess.

Basically, the roof has to be treated as 'tenent' space, unless all the rooftop equip is fed from a 'house' panel (landlord)

Perhaps George can jump in here...

I agree with John. The only way I think I could accept that is if it was on the house panel.

I don't have any code references that say that a receptacle for the roof top HVAC has to be fed from any particular source. This to me is a landlord/tenant issue. Greg's house panel might be the best answer. I just went through this with the sign circuits for a strip mall, where the sign circuits came out of the house panel which was in a locked room. Nothing in the code says that is illegal either.

Had one job where one tenant was plugging in his Xmas lights into a service receptacle for his next door tenants HVAC unit.

All these things are not electrical violations. IMHO

Every shell I've constructed had 'festive lighting' circuits on the house panel AND across a timing switch.

Well, Tesla, consider your future tenants lucky!

Code only says there be power for the convenience of the serviceman. Code is silent as to where that power comes from - or whether it is there under every tenancy circumstance.As the code is wriiten, you could meet the requirement if your neighbors' house had a receptcle nearby. 25 ft. is 25 ft!

A major part of my work has been in remodelling these types of commercial spaces. Joining units, dividing units, moving walls about. It's pretty hard to tell what the future will bring.

A similar situation arises with the ICC requirement for 'lighting the path of egress.' With every remodel, the new tenant gets to 'improve' the landlords' building.

I call it a design matter, and not a compliance issue. Code is supposed to be 'minimal' and 'practical.' That there might be a more elegant solution is not the question.

Reno:
I understand where you are coming from with reference to the 'neighbors' receptacle, and the verbage as written within the NEC. That is the reason I did not reference a code article.

As to using the neighbors electricity, that may be stretched out to a 'theft of services' type issue, and again NOT an NEC issue. Imagine that scenario with two neighbors that are not friends!

Yse, it is a design issue, no I cannot put a 'code' article on it for a violation, and I must add...I have never come accross this issue as an inspector. Both in new construction, tenant fit-ups, or replacement RTUs.

John, I'm sure that such juice is stolen at every opportunity.

The more seasoned landlords are 'hip' and thusly have house circuits...

'Nuff said.

BTW, these were well engineered major shell projects.

The landlord re-billed the tenants for such loads...

Another circuit that I've run into is a separate GFCI aux to the RTUs...

The idea is that any HVAC tech can cut the power at the disco -- yet still have aux power at the GFCI receptacle....

These are the norms that I have to work towards....

Regardless of the NEC.

Tesla:

I'm not saying there are no 'juice thieves' here on the east coast, and yes I know a few.

My point, I have not had anyone argue/dispute the RT receptacle within 25'. A lot of the new RTUs have the GFI within the RTU, fed by a 120 volt circuit.

Or you could suggest that they bite the bullet and install a combination swtich/receptacle where the receptacle is tapped off the line side. It saves the cost of running a separate 120V circuit so it might work out to the same installed costs when all is said and done.

I think Tesla's talking about these:
http://www.eaton.com/Electrical/USA.../SafetySwitches/AuxiliaryPower/index.htm

Ghost:

"Or you could suggest that they bite the bullet and install a combination swtich/receptacle where the receptacle is tapped off the line side. It saves the cost of running a separate 120V circuit so it might work out to the same installed costs when all is said and done"

I think you do not mean to tap off the AC feeder on the line side! Correct?

The receptacle is fed from a small (properly fused) transformer that is tapped off the line side of the HVAC feeder. That way you will still have 120V power when you open the local disconnecting means for the main unit.

Ghost:
OK, that's a professional way!

John,

I will agree that there should be a new recptacle on the existing HVAC. However if you read the code, it just says "Need a receptacle within 25' of unit". So this install would meet the code.

If he adds a new HVAC unit, then I think I can make him add a recpt. but if the HVAC is existing, maybe not under Rehab?

Harold:
1990 NEC was 75'; 93 changed to 25', and to date there is no requirement in the NEC for where the 120 volt originates from.

Using the "Rehab Card" gets them a 75' distance IF the original unit was pre 1993 install, after that 25'.

Getting deeper into this, a existing building being renovated, with no change in volume, installing RTUs today is under the 2005 NEC

Source is still the 'wild card'!

John,

The plumbing inspector just told me how an*l are we to be discussing this small (minute)( pronounced My-nute) of a problem. I explain to him that the NEC tries to be very specific about it's wording and meaning. Yet we as individuals, have to try and carry out day by day installations and inspections with out going crazy over the small things.

Plumbing inspectors usually have comments similar to that regarding all sparkies!

Plumbing inspectors only have 2 violations they can cite, don't they?

"Cold water is not on the right"

"Poop is not flowing down hill"

Wasn't there a "Three Stooges" clip about them trying to fix the plumbing in a house?

They pulled down a piece of conduit and figured the reason that the water didn't work was because the pipes were all clogged with wires.

Greg,

You forgot one important fact about plumbers. Don't bite your nails!

I worked with a plumber for several years who told me that he never ate his whole sandwich for lunch whenever he was 'working with the tools'. He would open his lunch and hold the sandwich by a corner with 2 fingers; he would only eat the part of the sandwich that he didn't touch.

That is why fast food comes in that plasticized paper wrapper.
You don't have to waste any.

I'm getting confused again guys- How did we traverse from rooftop receptacles to the plumber not chewing his nails and throwing away that last bite of his sandwich?

Allowing a little 'sparky' humor into this thread...

Had a girlfriend once who wouldn't eat the last bit of her sandwich, she had other problems too

She must have grown up in a plumber's household.

No plumber ever eats all of his sandwich.