SEC tap

[nickelec]

Is it permissible to splice SEC's in a panel before the main breaker to supply another panel off the same meter.

If so say thisnis an existing 200 amp MBP fed via 3/0 copper. And I want to splice in to these SECs in the panel to feed a small 40/50 amp panel. I can't find anything that says I can't ..

Typically I would use a wire way if some sort but being this is existing we're trying to work with in the space allocated already.

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[kwired]

If there is sufficient room for conductors and splices.

Also need to make sure the load calculation isn't over the ampacity of the supply conductors.

 

[nickelec]

If there is sufficient room for conductors and splices.

Also need to make sure the load calculation isn't over the ampacity of the supply conductors.

Yes absolutely I'm not worried about that. I'll give you some back story. A client had some solar contractors install solar on about 20 buildings.

The new combiner panel is fed via 3/0 copper to a main 200amp shunt trip breaker. With about 4 30 amp circuits on it.

They also fed the house panel from this panel.

So when you hit the Emery shut off outside it kills the house panel.

They want to hire me to fix it.

So what I'm looking to do is basically feed the existing house panel with a new cable/conduit etc without moving or redoing the layout. Hence needing to splice before the breaker.

My main question was is there any rules in regards to what size the conductors can be.

For example. One building has a 30 amp sub panel for the house panel. Can I tap the 3/0 with a set of #10s or is there a calculation.

I don't believe tap rules i.e. 1/10 or 1/3 apply here.

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[LarryFine]

I believe that tap rules do apply.

 

[wwhitney]

I believe that tap rules do apply.

It depends on whether the conductor being "tapped" is a service conductor, or a feeder. I'm a bit unclear from the description.

Cheers, Wayne

 

[augie47]

If you are "tapping" onto service conductors the Art 240 tap rules do not apply as it does not meet the definition of a "tap"
The Art 230 rules including grouping of disconnects would apply.

Why is there a shunt trip to begin with ??

 

[infinity]

As Augie stated service conductors are never "tapped". 240.21 taps apply to feeder taps not service conductors. The word "tapped" is often used in this context even though there are no NEC tap conductors.

 

[jaggedben]

Yes absolutely I'm not worried about that. I'll give you some back story. A client had some solar contractors install solar on about 20 buildings.

The new combiner panel is fed via 3/0 copper to a main 200amp shunt trip breaker. With about 4 30 amp circuits on it.

They also fed the house panel from this panel.

So when you hit the Emery shut off outside it kills the house panel.

They want to hire me to fix it.

What needs fixing? Have vandals been hitting the emergency shutoff? There should be no situation in which someone legitimately needs to trip the emergency shutoff where they wouldn't also want to turn off power to the building.

Also why exactly was the emergency shutoff needed? Is the 200A main breaker not readily accessible? Is it inside in a one or two family dwelling? Can the shut trip circuit and shutoff just be removed to supply a 'fix'?

So what I'm looking to do is basically feed the existing house panel with a new cable/conduit etc without moving or redoing the layout. Hence needing to splice before the breaker.

My main question was is there any rules in regards to what size the conductors can be.
...

(Assuming there isn't a better solution...)
That generally sounds fine. Hopefully you aren't running up against the maximum of 6 service disconnects. The minimum size wire for SECs is 6awg.

 

[kwired]

As Augie stated service conductors are never "tapped". 240.21 taps apply to feeder taps not service conductors. The word "tapped" is often used in this context even though there are no NEC tap conductors.

Tapped is kind of a generic term.

240.21 is about "feeder taps".

Service conductors are not feeders, so "feeder taps" doesn't apply.

I know you know this, just clarifying some for anyone that doesn't know it.

 

[don_resqcapt19]

230.46 Spliced and Tapped Conductors.
Service-entrance conductors shall be permitted to be spliced or tapped in accordance with 110.14, 300.5(E), 300.13 and 300.15. Power distribution blocks, pressure connectors, and devices for splices and taps shall be listed. Power distribution blocks installed on service conductors shall be marked “suitable for use on the line side of the service equipment” or equivalent.

Pressure connectors and devices for splices and taps installed on service conductors shall be marked “suitable for use on the line side of the service equipment” or equivalent.

 

[infinity]

230.46 Spliced and Tapped Conductors.
Service-entrance conductors shall be permitted to be spliced or tapped in accordance with 110.14, 300.5(E), 300.13 and 300.15. Power distribution blocks, pressure connectors, and devices for splices and taps shall be listed. Power distribution blocks installed on service conductors shall be marked “suitable for use on the line side of the service equipment” or equivalent.

Pressure connectors and devices for splices and taps installed on service conductors shall be marked “suitable for use on the line side of the service equipment” or equivalent.

The NEC tells us that feeder taps are covered under Article 240 and then uses the word tap elsewhere in the code when actually there is not a tap conductor involved.

 

[don_resqcapt19]

The NEC tells us that feeder taps are covered under Article 240 and then uses the word tap elsewhere in the code when actually there is not a tap conductor involved.

That is why the (240) appears at the end of the tap conductor definition.

Tap Conductor.
A conductor, other than a service conductor, that has overcurrent protection ahead of its point of supply that exceeds the value permitted for similar conductors that are protected as described elsewhere in 240.4. (240) (CMP-10)

That (240) tells us that the definition only applies in Article 240.

I think this concept worked better when the definitions that only applied to a single article were found in the xxx.2 section of the article that the definition applied to. The moving of all of the definitions to Article 100 has made this concept more difficult to understand.

 

[nickelec]

It depends on whether the conductor being "tapped" is a service conductor, or a feeder. I'm a bit unclear from the description.

Cheers, Wayne

These are service conductors

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[nickelec]

If you are "tapping" onto service conductors the Art 240 tap rules do not apply as it does not meet the definition of a "tap"
The Art 230 rules including grouping of disconnects would apply.

Why is there a shunt trip to begin with ??

Honestly I'm not sure I didn't design the system. I'm being told it for fire department shutdown.

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[nickelec]

What needs fixing? Have vandals been hitting the emergency shutoff? There should be no situation in which someone legitimately needs to trip the emergency shutoff where they wouldn't also want to turn off power to the building.

Also why exactly was the emergency shutoff needed? Is the 200A main breaker not readily accessible? Is it inside in a one or two family dwelling? Can the shut trip circuit and shutoff just be removed to supply a 'fix'?



(Assuming there isn't a better solution...)
That generally sounds fine. Hopefully you aren't running up against the maximum of 6 service disconnects. The minimum size wire for SECs is 6awg.

I think this is the simplest fix due to the existing layout . And yes the disconnect is located not in a readily accessible area. And it is 3+ families

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[jaggedben]

I think this is the simplest fix due to the existing layout . And yes the disconnect is located not in a readily accessible area. And it is 3+ families

If the 200A service disco is not in a readily accessible area then you can't install a new service disco in the same area. And the existing disco is in violation. 'Readily accessible' does not mean it is not behind locked doors. I guess when I asked above it was a rhetorical question: I expected the existing service disco to be readily accessible.

I've yet to hear why the emergency shut trip was code required. Local ordinance perhaps? Or just someone misunderstanding the code?

 

[augie47]

If the shunt trip is required for the existing panel by fire dept or whomever, the added panel would likely have to be treated the same.
I would follow up on that requirement before adding a panel.

 

[nickelec]

If the shunt trip is required for the existing panel by fire dept or whomever, the added panel would likely have to be treated the same.
I would follow up on that requirement before adding a panel.

I wouldn't be adding a panel.

The panel in question was existing and is only now being fed via this new shunt trip controlled combiner panel because the client is trying to benefit from the meterd solar system

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[nickelec]

If the shunt trip is required for the existing panel by fire dept or whomever, the added panel would likely have to be treated the same.
I would follow up on that requirement before adding a panel.

Here's a Pic. You can see the panel in the right is the existing house panel.. the new panel on the left is the combiner panel for the new solar system. The house panel is fed from said shun trip controlled MBP.

All we're trying to do is have the house panel in the same meter but not be subject to the rapid shutdown

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[jaggedben]

So are there any service disconnects in that pic? I'm still unclear on the 'why' of it all. If the service disconnect is in that pic and considered compliant, then there was no NEC requirement for the shunt trip. If there was an NEC requirement for the shunt trip, then it's not compliant to put a new service disconnect in that room and I don't know what your plan should be. If the shunt trip was required by some local rule then go ahead with your plan. If the shunt trip was required erroneously then perhaps just remove it.