Design review request for 200amp meter upgrade

Question

I am looking for eyes on a 200amp upgrade for my family's property to make sure I'm on the right track. Appreciation in advance for any improvements or refinements of the plan. I'm located in Monterey county, California.

Our current setup is this pole with a meter with 50amp service. It currently provides power for a small barn and a well. (This is a secondary meter on site that previous owners had for their sheep rearing business.)

We are building a small office/workshop space nearby and hope at some point to upgrade it to an ADU so just want to prepare the electrical accordingly. I received the permission to call PGE and perform the disconnect to switch out the meter to receive 200amp service but want to make sure I have the right design.

My goals are to 1) reconnect the current breakers to the well & barn and 2) have a way to provide 200amp service to a new 1000 sq ft workshop/office when that is built next year.

I bought this Siemens Meter-Load Center Combination, 12 Space, 6 Circuit (https://www.amazon.com/gp/product/B00L2HFH6C/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1) but there are not any lugs to send the SE cable out. It I guess just operates on the 'less than 6 switches' rule for NEC and has no main disconnect.

So, With this meter load combo could I....

1. reattach the two double pole 50amp breakers for the well and barn
2. and then install a 100amp double pole breaker (providing total 200amp) that could send power to a future subpanel about 20' away for the new structure?

The future subpanel will have maybe 10 different breakers or so: AC, light zones, dryer, electric stove, various outlets, hot water heater, maybe a car charging port in future, etc... Here's a sketch of proposed design:

I think with taking up only 6 spaces total and only 3 switches to throw, I'd be good for fire code? Newer NEC codes might still require an actual disconnect though? If it does work, what size wire would be appropriate to send from 200amp breaker to the subpanel?

Let me know thoughts. I'm open to returning this meter main panel if there's a better design.

Thank you!

Answer 1

Research first. Then buy.

Harper's corollary: Buy the wire LAST.

Fire your purchasing agent. In fact, don't have your new guy purchase anything until the research is complete.

I bought this Siemens Meter-Load Center Combination, 12 Space, 6 Circuit but there are not any lugs

Yeah. Back it goes.

Your application is common (at least in North America): sprawling compound, service on a pole, and the desire to web power out to several outbuildings while also sending the whole kaboodle to the house. We have the perfect panel for that, it's called a ranch panel. Meter + main breaker + 8 breaker spaces + the thru-lugs to send 200A to the house. Here's one with meter pan and one without. These things are absolutely perfect for your application - it's what they're designed for.

However... whatever you use for a meter pan (integrated into the ranch panel, or separate) must be on the list of models approved by the power company. They are your first stop while shopping. If it's not on their list, the power company truck will drive away.

and then install a 100amp double pole breaker (providing total 200amp)

That is not how that works. A 100A double-pole breaker is 100A. Just, it's 100A at 240V instead of at 120V. It's weird, here's a primer.

Cable type

to send the SE cable out

Say whaaaaa?? No, you can't use SE cable underground or hung from a pole line, so I do not see how would get the power to your buildings. You need something else like XHHW in conduit underground (18" cover for PVC, 6" for RMC), or MH feeder direct burial at 24" of cover underground, or quadplex on a pole line. And you will need 4-wire cable.

Are you speccing these things because you are studying exactly what was done with the last installation? Don't. It's a tire fire compared to modern code.

Rule of Six is dead for services

I guess just operates on the 'less than 6 switches' rule for NEC and has no main disconnect.

OperateD past tense. This is probably done in the 60s or 70s when there was a different sensibility toward Rule of Six. Back in the day, 100A+ breakers were extremely cost-prohibitive, so up to six 15-60A breakers could serve as the main breaker. Under the old rules they could even add up to more than the service size, if the dwelling Load Calculation validated. Trouble was, someone would have to re-do the Load Calculation every time they added anything - no one did, and panels burned. So that rule is gone.

The only way multiple breakers are allowed for a service is in 300A and larger services, because breakers larger than 200A are cost prohibitive. So a 400A service is dual 200s. They are not paralleled, they must feed 2 separate panels.

The AHJ's view will be that since ranch panels are readily available at sane cost, they won't authorize one of these.

Rule of Six continues to be allowed for subpanels, and is allowed to be oversubscribed because there is a main breaker upstream.

Don't "optimize for cheap" on panels

I couldn't imagine why you bought a $500 panel over a $350 ranch panel, until manassehkatz explained that the mail-order price is highly distorted and it normally goes for $125-ish. Ahhhh, got it. It was cheaper.

The future subpanel will have maybe 10 different breakers or so: AC, light zones, dryer, electric stove, various outlets, hot water heater, maybe a car charging port in future, etc.

Right, and you want the cheapest panel that will do the job. That thing there? Don't do that. That leads to the #1 panel problem we get around here: "Help! My panel is full because I did not foresee future needs!"

And by the way, you are wildly underestimating the breaker spaces needed for a dwelling. You are assuming that if you can't imagine it, it doesn't exist. The kitchen alone can account for 10 spaces. We regularly see dwellings fill a 40-space panel.

To make matters worse, you can't really use tandems in California, so that "20 space 40 circuit" number is useless.

And the way panel pricing breaks out, spaces are cheap up to 42 spaces. So we recommend a 40- or 42-space panel for literally every dwelling. You'll begrudge us the extra $100 now... but you WILL thank us later.

By "later" I mean early into the build when the AHJ explains how many circuits you actually need. Also, are you flipping this place or do you actually plan to live there? Because an even bigger blunder we see is the guy who is penny-hoarding while building, but creates an unlivable house: The girls can't run their hair dryers at the same time because somebody put all the bathrooms on the same circuit. Can't cook a big-family breakfast because somebody fit only 2 kitchen receptacle circuits. Electricity is our servant, it's there to serve us, not make us dance around its limitations. Romex is cheap. NEC is the slumlord bare minimum, below which the home is unfit for human habitation. It's not a design guide.

Don't worry, there are lots of other places for "optimizing for cheap" that we'll be happy to help with. Aluminum wire is top of that list, and come on back when you're ready to do that EV circuit and we'll save you a bunch there too.

Answer 2

Please confirm this specific box was on a list from PGE or specifically approved by them in some way, preferably not just verbally. Each utility has particular meter panels that they approve. The lists change over time, and they may allow certain exceptions due to supply shortages. But if you get the wrong thing they won't connect your service.

Assuming that this is an approved box:

The breakers count as the disconnect. They are the first thing after the meter. Rule of 6 in general is not a great thing these days, but this box is specifically designed for that - instead of "12 space/12 circuit" (like a regular panel might be) or "12 space/24 circuit" (double-stuff everything) it is "12 space/6 circuit" - i.e., you only put 240V double-breakers in here, with a maximum of 6 throws, conveniently matching Rule of 6.

(I really hope the Amazon link was just for easy reference. It lists for $ 496 at Amazon! Only $ 125 at Home Depot. Home Depot is out of stock, but that gives you an idea of the correct price.)

Do NOT reuse the old 50A breakers. They might fit. But they are Challenger, which is generally not a good thing. And they have been sitting out for many years. Not worth the possible small savings compared to the risk (and that's assuming they are compatible in the first place). Siemens QP 50A double-breakers are around $ 15 each at Home Depot, and maybe less at an electrical supply house.

100A breakers are a bit more expensive, which is not surprising, but readily available. You have a reference of "200A breaker to subpanel" - pick one. (Harper caught what I didn't - referring to 100A double breaker as 200A - that is 200A @ 120V (which almost nobody needs) but 100A @ 240V (which is actually on the small side for a modern all-electric house). To figure out how much power you need, which will determine wire and breakers, you need to do a load calculation. Actually, do three load calculations - one for the barn, one for the well and one for the new building. The total of all 3 must stay under 200A, but you may end up with, for example, 30A at the barn, 20A at the well and 150A at the new building, in which case you are OK for 200A service but would actually have 3 breakers here (50A, 50A, 150A or 200A) that add up to more than 200A - and that's OK.

For the feed to the new building, use aluminum wire. What size will depend on the size of the breaker in the meter panel. There are a bunch of other factors that may come into play here as feeds to an entire building are different from ordinary circuits. Once you figure out the actual breaker size, one of the real experts will tell you what you need.