Adding optional building generator to a building with a fire pump.

[Bjenks]

I am being asked to quote a design to add a generator that would back up a full 6 unit condo with house power (includes elevator) that was built in the 70's. Besides knowing that cost will be too much, I see a fire pump issue that I am wondering if anyone sees a solution too. A utility transformer feeds 3 phase power into a 1200A MLO ITE panelboard. an 800A breaker send a feed to a meter center (not a problem). a 300A breaker feeds a small wireway with 2 taps (1 to an elevator fused disconnect) and the other a 225A MB panel (House Panel). ONe of the house panel circuits has a 3 pole 60A breaker that goes to a fire pump room's (through the building) controller.

Today I would assume you would require a generator as I am sure the power source isn't reliable. I would also supply the service to the UL listed controller from a source before the 1200A panelboard.

That being said, is it worth even thinking I might be able to just install a generator to an ATS that feeds the 1200A panelboard and just ignore what is a downstream problem? Or should I assume we will need to pull the fire pump controller off the house panel? The existing controller doesn't even have a breaker in it so that would then have to be upgraded to a service rated UL controller. If I replace that then I worry they will say I now have to supply a generator to it. Just trying to figure out how address this in my proposal. Further the feed to the existing 1200A panelboard comes up from the bottom and just to tap ahead of that panelboard will require a separate run from the transformer to be ran.

 

[RB1]

Bjenks,

These are questions that only the AHJ can answer. I can tell you from my position, seated upright, that the SUSE transfer switch install is going to cause some major heartburn. The only way the installation can exist with respect to the code is "existing nonconforming". The addition of another disconnecting means ahead of the existing service equipment can only exacerbate an already bad situation. I don't know of any AHJ that is going to go for that, and in this case you have to satisfy two, the Fire Marshal and the Chief Electrical Inspector. I would write my proposal to include the remediation of the fire pump feeder as an add-alternate and let the owner take it up with the appropriate city officials.

 

[Joe Villani]

It looks like you're going to have a metering problem.

Based on your proposals , the tenants would be paying the utility company when they are generator power????

Based on the building type and the building classification the fire pump may not require back-up power. As RB1 said check with the AHJ on that one

 

[Bjenks]

Based on the building type and the building classification the fire pump may not require back-up power. As RB1 said check with the AHJ on that one

I might have overstate that the power source is unreliable and thus not require an alternate source. However, one of the questions I am pondering is: Does adding an optional generator that supplies a complete building (including a Fire Pump that doesn't require a generator) have to meet the generator requirements of NEC 695 for VD, dedicated ATS, and not sharing the same circuit of the non-fire pump circuits? Or can I just say it is an optional generator and I only need to follow NEC 702?

 

[GoldDigger]

If you want ti avoid special wiring requirements, I would say that you would have to specifically NOT supply the fitr pump from the generator.
My take would be that whenever you install something special which is not required, the full code for that special thing applies.
An overly simple example is that when you pull an unnecessary wire EGC in a raceway it must still meet all of the EGC requirements.

 

[Smart $]

It looks like you're going to have a metering problem.

Based on your proposals , the tenants would be paying the utility company when they are generator power????...

The way the OP is written up, I couldn't discern whether the house loads ran through the meter center or not. I was leaning towards not... as in the 300A breaker is in the 1200A MLO panel.

A utility transformer feeds 3 phase power into a 1200A MLO ITE panelboard. an 800A breaker send a feed to a meter center (not a problem). a 300A breaker feeds a small wireway with 2 taps (1 to an elevator fused disconnect) and the other a 225A MB panel (House Panel). ONe of the house panel circuits has a 3 pole 60A breaker that goes to a fire pump room's (through the building) controller.

Regardless, I can't imagine a POCO permitting accessible equipment ahead of metering. Also, all POCO's I've dealt with require CT metering for that size of service, and ahead of any service equipment.

If the POCO does use load side metering for tenant accounts, it would be balanced against total usage per the CT metering... where the "house" gets charged for the balance. If this is such a situation, and there is no load-side metering of the house load, you are correct in that tenants would be paying the POCO for generator power... but the beneficiary of that extra charge would be the house, not the POCO.

 

[d0nut]

I might have overstate that the power source is unreliable and thus not require an alternate source. However, one of the questions I am pondering is: Does adding an optional generator that supplies a complete building (including a Fire Pump that doesn't require a generator) have to meet the generator requirements of NEC 695 for VD, dedicated ATS, and not sharing the same circuit of the non-fire pump circuits? Or can I just say it is an optional generator and I only need to follow NEC 702?

If the power source was reliable, the owner would not be asking you to install a generator. My opinion is that any facility with a generator and a fire pump has to supply the fire pump from the generator and meet the requirements of Article 695. In your situation, I would recommend separating the fire pump from the rest of the building distribution and meet the requirements found in Article 695. Routing the fire pump conductors through the building may present its own set of challenges. I don't have my code book in front of me, but if I remember correctly, those conductors are required to carry a 2 hour fire rating.

 

[iwire]

My opinion is that any facility with a generator and a fire pump has to supply the fire pump from the generator

That is up to the AHJ and / or local rules.

For instance in MA we have rule 3 which allows additions or modifications to existing installations without bringing the rest of the work up to current code.

So in my opinion in MA the OP would not have to power the fire pump from the generator.

 

[iwire]

Regardless, I can't imagine a POCO permitting accessible equipment ahead of metering.

They do here, such as service disconnects. ( Not meter disconnects)

Also, all POCO's I've dealt with require CT metering for that size of service, and ahead of any service equipment.

If the POCO does use load side metering for tenant accounts, it would be balanced against total usage per the CT metering... where the "house" gets charged for the balance.

I have done a lot of condos and apartments and have never seen such an arrangement. The 'house' would get their own dedicated metering equipment, either plug in or CT as appropriate for the load.

 

[Bjenks]

Sorry guys, I see the confusion is that I left out the CT-Meter from the 300A breaker to the small gutter tap to meter the house power.

 

[Bjenks]

On a side note about accessibility before a meter issues... My inspection found 2 big issues: 1) somewhere along the way someone tapped off the gutter to the right that fed the meter center and ran power to a lift station. The lift station has no meter on it either so as far as I can tell free power for the lift station. 2) When they tapped off the horizontal bus to the fused disconnect they also decided to run an additional 4/0 from the 800A breaker to the same landing as the 400 MCM. In essence they are paralleling a lower impedance conductor with another.