Tap conductors from an unmetered main without overcurrent protection

[johnsciolino]

Seem people are getting really creative these days with the shortages and long lead times on large equipment.
I have a buildout on a building that has nothing more than a 4000amp terminal box which is also located inside the building. This obviously creates some challenges since the 10 and 25ft tap rules would apply now. The service conductors are rated for up to 4000amps at 480 volt. They don't plan on having any more than 6 services but several other issues come to mind (emergency disconnect rule and GFI protection for 480v services).
Does 240.21 (c)(5) apply? (secondary conductors from a feeder tap transformer) I wouldn't think so since the transformer is a utility xfrmr and primary over current protection is not coordinated with our electrical installation.
240.21 (b)(2) says a 25' conductor can be used if the tap conductor is at least 1/3rd the rating of the over current device feeder the tap conductors. There is no over current device so now what?

I cant see how any of this even meets NEC requirements.
If the tap can were outside, it would be a different story...

Lately, we have been just installing the conduits to the utility transformer and pulling in the service conductor as required for each service. With the new emergency disconnect rule, I think we also need a switch ahead of the meter.

 

[infinity]

If this terminal box is before the service disconnects no Article 240 taps rules would apply becuase they're still service conductors.

 

[johnsciolino]

There is no service disconnect. I think they are trying to apply the "6 hand rule" and simply installing feeder conductors to a tap.
If they are still service conductors, don't they have to terminate to a breaker once inside the building?

 

[infinity]

There is no service disconnect. I think they are trying to apply the "6 hand rule" and simply installing feeder conductors to a tap.
If they are still service conductors, don't they have to terminate to a breaker once inside the building?

Yes there has to be a service disconnect(s). Anything "tapped" upstream of the service disconnect(s) (not a feeder tap by definition) does not follow the tap rules in Article 240. Feeders only begin after the service disconnect(s).

 

[augie47]

"Lately, we have been just installing the conduits to the utility transformer and pulling in the service conductor as required for each service. With the new emergency disconnect rule, I think we also need a switch ahead of the meter."

The only emergency disconnect rule of which I am aware is 230.85 for one and two family dwellings.

Are there not any engineered drawings ?
What Code cycle is applicable ?

 

[Jarrett McFatter]

As you can see in the attached one line, this tap box is what John is referring too.
Can you shed some light on how this meet Article 240?

 

[augie47]

It might well meet Art 240 as far as overcurrent protection but the 240.21 "tap" rules do not apply to service conductors.
240.2 defines a tap conductor and requires a 240.21 tap to be protected by an overcurerent device at it's supply.
The conductors routed to the CT cabinet and disconnect are service conductors subject to the rule sin Art 230/

 

[infinity]

As you can see in the attached one line, this tap box is what John is referring too.
Can you shed some light on how this meet Article 240?

So this is the actual drawing from the question in the OP? There are no tap conductors between the termination cabinet and the disconnect switch. The 200 amp disco could be fed with 1 set of #3/0 copper.

 

[don_resqcapt19]

What part of the installation shown on the drawing is inside a building?

 

[johnsciolino]

What part of the installation shown on the drawing is inside a building?

Everything except the fire pump meter is inside the building.

 

[augie47]

I see nothing wrong with the concept. You are at the mercy of the local jurisdiction as to the allowance on the length of the conductors to your disconnect as 230.70 does not specify a length. I would also be concerned with 230.72 depending on the location of the "Future Tenant Disconnects" in relation to the one shown.

 

[infinity]

It seems that the designer was using the 10' rule for feeders which does not apply here. Also the EGC's shown in the two parallel raceways are incorrect, there is no EGC before the service disconnect therefore they should be removed.