MSP suited for whole home battery back up

[Zee]

It is very difficult, if not impossible, to back up a whole home when presented with an existing service panel (MSP) that is of the combination type: meter and breakers all in one enclosure. This is due to the bus bars being inaccessible between the meter and main breaker, and also the main breaker and bus bar. Or they cannot be tapped or re routed in a Code compliant manner.
Such a panel cannot be fed by a battery system.

I have two home-owners who are planning a 200A service ugrade.
Anybody know of a good make/model of a combo service panel that would be ideal for such a panel upgrade if they are also planning on getting a battery?

Right now I am left with recommending a separate meter and main panel.
In such cases the field wiring between the two can be accessed, diverted and modified.

 

[jaggedben]

I think Square D's 225A busbar panels are probably the best. The only disadvantage is if you're cramped for space they are wider. But having a full width panelboard in a meter main is nice. The busbars between meter and main are able to take CTs in my experience.

 

[EJPHI]

Since your are in California, you may not have much choice as many jurisdictions require EUSERC compliant panels.

 

[ramsy]

Electric Utility Service Equipment Requirements Committee "EUSERC"
..There are now 80 utilities involved in EUSERC from 14 states.

EUSERC publishes a revised requirements book (manual) annually. See a EUSERC drawing.

The above drawing published in 2002 shows a Meter Combo specified with 125A or 225A options.

No Big-box stores in Sourthern Calif. stock 225A in anything, and never did, so compliance may be questionable.

Since EUSERC is not NEC nor NRTL, it may be in the "Electrical Requirements" published by the POCO's.

Without any EUSERC identified markings on equipment, to describe compliance for AHJ inspectors, it appears enforcement is subject to POCO's during the meter spot. Since no one cares to stock 225A, it appears they are not in demand nor installed.

 

[EJPHI]

Yeah ramsy you have this right. The last time I ran into EUSERC, the AHJ and the POCO were one in the same although in different departments!!

 

[EJPHI]

And in fact, the EUSERC requirement was driven by the POCO department of the city.

 

[ramsy]

Southern California Edison's (GMA), and SDGE's (RMA) meter-adapter options require:
1) "Main breaker and meter socket must be contained in the same electrical panel", and
2) "An electrical service panel that has no current Electrical Service Requirement violations."

This presents a supply-side "Solar-Ready" advantage for EUSERC equipment, when bidding against the typical panel flipper's non-compliant equipment that must be ripped out --at great expense-- before any Net metering/Grid tied generation is approved by the electric utility.

 

[wwhitney]

I think Square D's 225A busbar panels are probably the best.

Can you be more specific? Square D's January 2021 catalog only lists one "all-In-one" with a 225A bus rating, and the webpage for that item (SU3040M225R) says "discontinued on January 23, 2021."

Seems like what the OP would like is an "all-in-one" where the conductors from the meter socket to the main breaker, or from the main breaker to the distribution bus, are of the the wire type and the manufacturer allows field modification of those wires. So that they can be rerouted to an external Microgrid Interconnect Device and then back.

Thanks,
Wayne

 

[curt swartz]

Can you be more specific? Square D's January 2021 catalog only lists one "all-In-one" with a 225A bus rating, and the webpage for that item (SU3040M225R) says "discontinued on January 23, 2021."

Seems like what the OP would like is an "all-in-one" where the conductors from the meter socket to the main breaker, or from the main breaker to the distribution bus, are of the the wire type and the manufacturer allows field modification of those wires. So that they can be rerouted to an external Microgrid Interconnect Device and then back.

Thanks,
Wayne

I agree. the back feed is not the issue, isn't interrupting the utility feed. You will not be able to do this with a single unit. Install a meter-main that feeds the battery backup equipment then a loadcenter for all loads.

In reality you are probably not going to want to back all loads unless you are installing serious battery backup. Even if the batteries can take the load they are going to drain very quickly and the customer will loose power.

For a home with a 200 amp service we will typically install the large loads at the service then run a feeder to the backup loads. The backup up loads frequently end up being 99% of the small branch circuits.

Edited to add:
Several of Square D's 200 amp combination service entrance device's have 225 amp buss bars. SC3042M200PS and SC3042M200PF are 2 of them

 

[wwhitney]

Several of Square D's 200 amp combination service entrance device's have 225 amp buss bars. SC3042M200PS and SC3042M200PF are 2 of them

Ah, thanks for the numbers, I see that I overlooked the next section of the catalog, which is titled "Homeline Solar Ready PoN CSEDs", after all the other CSEDs. I don't see anything for QO breakers, though, just Homeline.

Those Homeline panels you mentioned also support subfeed lugs before the main breaker, so you can easily do a line side tap. Which would let you use the "all-in-one" for your non-backup panel, and run a separate service to the Microgrid Interconnect Device and backup panel/inverters. Of course you'd have to run CTs into the "all-in-one" if you want to use the energy storage to offset the non-backup load usage when grid connected.

Cheers, Wayne

 

[curt swartz]

Ah, thanks for the numbers, I see that I overlooked the next section of the catalog, which is titled "Homeline Solar Ready PoN CSEDs", after all the other CSEDs. I don't see anything for QO breakers, though, just Homeline.

Those Homeline panels you mentioned also support subfeed lugs before the main breaker, so you can easily do a line side tap. Which would let you use the "all-in-one" for your non-backup panel, and run a separate service to the Microgrid Interconnect Device and backup panel/inverters. Of course you'd have to run CTs into the "all-in-one" if you want to use the energy storage to offset the non-backup load usage when grid connected.

Cheers, Wayne

I have never liked Square D's idea of using a lug kit to make a line side tap. You end up having unprotected wires in the wiring gutter that can't be shut down to work in the panel. Trying to add a wire to the neutral buss which is in the very back of the panel would be scary.

When Siemens first came out with their PV ready CSED's they had a 2 pole breaker space that was connected on the line side of the main breaker. This made much more sense to me.

 

[jaggedben]

I did kind of miss the whole home backup part.

If you are replacing an existing panel and you want to do whole home backup with no non-backed up loads, just use the MID as the service equipment. The major ones support that.

Otherwise, 70A of backfeed is pretty substantial for partial home backup. Or downsize the main to 175A since many houses really don't need 200.

 

[Zee]

Seems like what the OP would like is an "all-in-one" where the conductors from the meter socket to the main breaker, or from the main breaker to the distribution bus, are of the the wire type and the manufacturer allows field modification of those wires. So that they can be rerouted to an external Microgrid Interconnect Device and then back.

Thanks,
Wayne

Precisely. I need to back up the main service with battery .
(I am not asking about PV point of interconnection in main service AKA standard solar backfeed to grid).

 

[Zee]

I agree. the back feed is not the issue, isn't interrupting the utility feed. You will not be able to do this with a single unit. Install a meter-main that feeds the battery backup equipment then a loadcenter for all loads.

In reality you are probably not going to want to back all loads unless you are installing serious battery backup. Even if the batteries can take the load they are going to drain very quickly and the customer will loose power.

Yep. I agree that a separate meter (or meter/main) plus a load center will allow the battery to cut in between the two (by way of a Microgrid Interconnect Device ).

Re overloading battery: In this case customer uses very little power - despite getting a new 200A service. The 200A is overkill big time.
No A/C , hot tub, pool, EV, elec. heat etc
He also has basic expectations for an outage: wants his fridge, garage door opener and some kitchen up and running. So I will back up the whole house given that all those circuits are in 3 different sub panels. We are on the same page.

(on a side note: I HATE critical load panels AKA dedicated load panels.........and the spaghetti of branch circuits, and split up shared neutral circuits that result. I try to back up an existing panel.)

 

[Zee]

Update: so the electrician doing the service upgrade will install a separate meter enclosure and separate main panel at my request.
They will be stacked as per usual, with a short nipple exiting down from the meter into the top of the main panel.

I need to re-route these short conductors (currently from meter down into main) thru the (N) MID (SolarEdge Back Up Interface) and then back to main breaker in main. I just realized the conductors from meter to MID will be unprotected conductors as they are upstream of any OCPD.

I will be getting the 200A service rated MID with 200A main breaker installed.

How best to do so?

Any Code limitations I may overlook?

 

[ramsy]

Where is your copy of utility electrical requirements.

Your power company will have very specific connection requirements on your supply side

 

[jaggedben]

Update: so the electrician doing the service upgrade will install a separate meter enclosure and separate main panel at my request.
They will be stacked as per usual, with a short nipple exiting down from the meter into the top of the main panel.

Why would you do that? Seems to me you want to put up your MID in concert with your electrician, and feed the MID directly from the meter. Or if you can't swing the coordination for some reason, have him put a large enough J-box in between meter and main that you can nipple out the side to your MID and back.

I need to re-route these short conductors (currently from meter down into main) thru the (N) MID (SolarEdge Back Up Interface) and then back to main breaker in main. I just realized the conductors from meter to MID will be unprotected conductors as they are upstream of any OCPD.

I will be getting the 200A service rated MID with 200A main breaker installed.

How best to do so?

Any Code limitations I may overlook?

If the MID is listed as suitable for service equipment then the code isn't going to have much issue. MID should have main bonding jumper make sure that you install it or leave it in place per instructions. Don't bond neutral at the downstream panel. Or maybe it needs to be a panel that your electrician can install an MBJ in inititially, and then you can remove it when you install the MID.

I think ramsy's point is well taken that you should run it by the utility because they may not be very familiar with an MID as service equipment yet.

 

[Zee]

...... put up your MID in concert with your electrician, and feed the MID directly from the meter........

That is ideal. Too late for that unfortunately. I will go out there and try to get a J box in.

 

[thekwhour]

yes there is a solution and I have been racking my time trying to find it. I know what your trying to do and the majority of people dont understand these solar ready combo panels will not work for whole home back up. Your on the right track as separating the meter from the homes load center. In fact any builder who is putting these all in ones installed, solar ready or not, are screwing people over if they ever want to do whole home back up.