Lay out help

[nickelec]

Good morning all have a few questions on this one

I've attached a one line for reference

Are the conductors for a solar system considered SEC

Also are associated switches service switches?

My plan is to put a 1200a CT cab and from there feed 3 - 400 a switches eliminateing the need for the 1000a showed. If I can

Depends on the amount of service switches already in the building hence my question about switches for pv being considered in th 6 switch rule..


If the 1000a main is needed I'm thinking two sets of 500mcm.

Any insight or design ideas would be appreciated View attachment 111-115 DeHaven Three Line.pdf

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[kwired]

Service entrance conductors are conductors that come from the utility, in your drawing they would be in upper right corner and would everything on the the supply side of "H"

Conductors derived from PV are not service conductors, they however could land on load side of a service disconnecting means, so every disconnect feeding PV with "service conductors" on the supply side would be counted as one of the six permitted service disconnects.

 

[nickelec]

I thought so , so if the building already has say 3 or 4 then my plan wouldn't work

I would have to use a main as pictured.

Wat do we do in the case a building already has 6 figure out a way to combine two I would assume?

I've yet to come across that issue in rela time

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[Carultch]

I thought so , so if the building already has say 3 or 4 then my plan wouldn't work

I would have to use a main as pictured.

Wat do we do in the case a building already has 6 figure out a way to combine two I would assume?

I've yet to come across that issue in rela time

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In your drawing, due to the fact that there is a utility service meter dedicated to the PV, this means the PV would be classified as its own service, that is independent of the service to the building as a whole, regarding the 6 disconnect rule. At least, that is how utilities interpret the definition of 1 service in my area. Per 230.2, the 6 disconnect rule, refers to 6 service disconnects on the same service. If you have multiple services to the same building, you get to have up to 6 service disconnects for each of them, provided that hot sequence metering is allowed. A logical consequence of cold-sequence metering by contrast, is that each service would have a single disconnect in front of the corresponding meter.

Service disconnect specifically means that service conductors are on its line side, which by definition come from the utility's service point, so you are free to have as many disconnects downstream of any individual service disconnect as you see fit.

 

[Carultch]

Unless you have a specific product in mind, the 1000A disconnect would most likely be a 1200A disconnect. There are 8 standard ratings of safety switches, which are 30A/60A/100A, then 200A/400A/600A/800A, then 1200A, then onto custom switchboards.

You might also want to make sure you plan that your fuse is possible to use with the disconnect you have in mind, since the rating you indicate is not a standard size in 240.6. I've seen 900A fuses before, although that isn't a standard rating either.

 

[Carultch]

If the 1000a main is needed I'm thinking two sets of 500mcm.

Remember that over 800A, the next size up rule doesn't apply anymore. You need at least as many amps of conductors as you have OCPD. The 75C termination ratings would most likely govern the sizing as well. You are looking at minimum 3 sets in parallel for 1000A.

 

[nickelec]

Remember that over 800A, the next size up rule doesn't apply anymore. You need at least as many amps of conductors as you have OCPD. The 75C termination ratings would most likely govern the sizing as well. You are looking at minimum 3 sets in parallel for 1000A.

I'm aware of the 800 amp rule yes ty for reminding me. I'm going to take a look at this project in person tomorrow I'll keep everybody updated

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[jaggedben]

In your drawing, due to the fact that there is a utility service meter dedicated to the PV, this means the PV would be classified as its own service, that is independent of the service to the building as a whole, regarding the 6 disconnect rule. At least, that is how utilities interpret the definition of 1 service in my area. ...

Not in my area. And not in the NEC.

 

[ggunn]

Not in my area. And not in the NEC.

Mike Holt had a training video few years ago where he and the experts he assembled went through the six handle rule and convincingly showed that a PV interconnection does not count toward it. It was a bit convoluted but I was able to use it to convince a couple of AHJs that a supply side PV interconnection isn't a seventh handle when there are already six service discos on the service conductors from the utility. What has changed in the NEC since then?

 

[jaggedben]

Mike Holt had a training video few years ago where he and the experts he assembled went through the six handle rule and convincingly showed that a PV interconnection does not count toward it. It was a bit convoluted but I was able to use it to convince a couple of AHJs that a supply side PV interconnection isn't a seventh handle when there are already six service discos on the service conductors from the utility. What has changed in the NEC since then?

The definition of a service, for one thing, which I believe Mike relied on heavily.

Also I don't think they showed anything 'convincingly', although I'm glad it worked out for you with those AHJs.

Also that's a slightly different point from Carultch's that I was responding to.

 

[ggunn]

The definition of a service, for one thing, which I believe Mike relied on heavily.

Can you point me to the specific language that changed?

 

[nickelec]

So I went out and looked today at the side conditions here's what we have

I attached a picture of a switchboard and the neutral inside the switchboard

coming directly from the utility into this cabinet are the service entrance conductors

so here we have five service switches

My plan is to either

A. tap the bus to feed a new service which for the PV system

B. Try to get a breaker because there is an empty slot to feed new PV system either way I'll be adding a sixth switch and I'm not worried about the rule or have it to argue about it..

My next question is the problem is the main water ground is about 600 ft away in an adjacent building .

I believe I could just run a bonding jumper from the new switch I install (if it's not a breaker) to the neutral inside this cabinet .

I plan to put the new service which about 6 or 7 ft away from this cabinet in the same room

anybody disagree?

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[nickelec]

also trying to figure out bonding jumper size for two sets of 600kcmill im coming up with 4/0

 

[kwired]

Mike Holt had a training video few years ago where he and the experts he assembled went through the six handle rule and convincingly showed that a PV interconnection does not count toward it. It was a bit convoluted but I was able to use it to convince a couple of AHJs that a supply side PV interconnection isn't a seventh handle when there are already six service discos on the service conductors from the utility. What has changed in the NEC since then?

The definition of a service, for one thing, which I believe Mike relied on heavily.

Also I don't think they showed anything 'convincingly', although I'm glad it worked out for you with those AHJs.

Also that's a slightly different point from Carultch's that I was responding to.

I'll take a stab at it, keep in mind this just my observation from what I have read.

Take a look at 230.40.

Each service drop, lateral, etc. shall supply only one set of service conductors, not exact quote but basically what it means.

One set of service conductors can supply six disconnecting means. Had this PV system had it's own drop, lateral, etc. might that be a separate service as permitted by 230.2? If so you can have six disconnects for that service, but it is tapped to same incoming drop, lateral, etc. so that just makes it one service with more than six disconnects.

230.71 in the section for service disconnecting means falls in line with this as well, it only allows more than six disconnects on "one service" for power monitoring equipment, surge protection, control power for GFP or power operated disconnecting means.