I am installing a 320 amp service on my new house in Lewis County, Washington and am a little confused as far as how to split the service.

I have my meter base set on a rack 200ft from the house because that is as far as PUD would go without adding a transformer. I have 3" schedule 40 coming from the meter base to the house with 500kcmil/500kcmil/350kcmil in it right now.

My questions:

  1. Am I required to have my 2/200amp disconnects installed at the meter base?
  2. If so then do I need to run new conductors to the house or is there a way to split the service at the house instead?
  3. If so then what do I use to do so and to downsize to something that the lugs on my disconnects and panels will accept?

Edit... I need to clarify my situation so that I can ensure getting proper and complete answers which so far you have been excellent about giving. This is a house that I have been building for my family, 100% by myself (ok I sub contracted the gutters).

As far as the equipment purchased so far, it was on a recommendation from the engineer at the power company that was fairly vague (regarding the meter base and disconnects and the 400+ feet of 3" schedule 40 that I had to install from the nearest available transformer to where pud was willing to put the meter and then to my house from there)... And then some brief information from the inspector when I called him out to approve backfilling the trench regarding the choice of wire.

Obviously needed to be asking more and different questions when he was here but live and learn. So anyhow this is actually a 320amp service (residential 400 I am told) that is necessary due to an on demand water heater for my radiant heat that requires 100amps itself (3/40 amp breakers). So what I have is as follows:

a Eaton cooper b line meter base catalog no 324n and 2 eaton Eccvh200r disconnects as well as 2 standard 200amp house panels.

  • How did this 500 kcmil wire come to be in the ground like that? What is the date on your permit? Is the permit still valid? Commented Mar 18, 2022 at 19:16
  • Well, those were the right people to ask. However power companies often get this wrong because they follow a different book called NESC, not NEC. The inspector is the last word, if the inspector approves it you are golden. Have you already bought the wires? Are they copper or aluminum? Commented Mar 21, 2022 at 20:07
  • Yes like i said the wire is in the ground already. Thats where i got hung up because it is my understanding that technically the NEC only sees the meter as a cabinet and special equipment inserted into the service conductors. If you didn't put any disconnect at the remote location you still have service conductors leaving the meter and therefore it should be allowable to split the service at the house? I just really wanted to confirm this prior to proceeding
    – C streight
    Commented Mar 21, 2022 at 20:52
  • That makes perfect sense to me, but we're in an arcane and rapidly changing area of Code sothe AHJ is the final call on the matter. The concern I have is, "how do you split 500 kcmil to dual disconnects?" You could do that with a (redundant) meter pan at the house - most 400A meter pans have 600kcmil on the utility side and dual 250 kcmil on the house side. A ranch panel would be a single enclosure instead of 3, and would provide four 240V breaker spaces for feeders to outbuildings. It could also let you easily downbreaker one side to 150A if the AHJ flags that 500 kcmil. Commented Mar 22, 2022 at 1:10
  • Would a gutter box with appropriate lugs installed do the trick? So into a gutter box with the 3" then into the 2 disconnects i already have and then into the panels?
    – C streight
    Commented Mar 22, 2022 at 4:24

3 Answers 3


What you may not know is Washington is on NEC 2020, which changes the rules for meter pans and disconnects. The industry has responded with affordable products that largely comply.

Keep in mind that when I say "disconnect", I mean "main breaker". It is simply not affordable to have a separate disconnect from a main breaker, so the main breaker is used as the disconnect.

Even if they were separate, the main breaker would have to be immediately after the disconnect, because you can't have a long run of non-breaker-protected cable waiting for a nail hit.

Prepare for the possibility that you bought the wrong meter base. It may be more expensive to "double down" on the wrong meter base than to junk it and get the right one.

You need disconnect switch(es) at the meter.

The most affordable way to do that is a unit called a "Meter-Main", which places both the meter and the main breaker(s) in a single unit.

Depending on how you read it, Code says you need either 2 disconnects or even 1 master disconnect at the meter. You need to talk to your AHJ (permit issuing authority), as 400A disconnects are not affordable, so most AHJs are authorizing dual 200A disconnects.

Really, the bottom-line is what the local amendments are and what AHJs are allowing, given that following the letter of NEC 2020 NEC 2020 on 400A services means very pricey equipment right now. As such, this is a conversation that you need to have with your AHJ, because only they can tell you which affordable options (if any) are available to you.

As for the equipment already installed, somebody specced that. The person who did either knows something we do not... or they don't and should be liable for any mistakes. I would stop taking their advice unless it aligns with what your AHJ tells you.

  • So seeing as how i already pulled the 200+ ft of 500/500/350 the only option is a 400Amp disconnect that is astronomically expensive or removing the wire i pulled previously and installing my 2/200amp disconnects at the meter and re pulling parallel feeders to my 2/200amp panels at the house...correct?
    – C streight
    Commented Mar 19, 2022 at 12:43
  • @Cstreight -- can't do the latter as that violates NEC 225.30, which prohibits 2 feeders to a building unless you fit into its list of specific exceptions Commented Mar 19, 2022 at 17:46
  • @Cstreight -- also: what prices are you seeing for 400A disconnect hardware? I'm trying to get a sense for what you're calling "astronomically expensive" compared to the numbers I've seen online for hardware in that class Commented Mar 19, 2022 at 17:48
  • @ThreePhaseEel OP may be getting that impression from me. Last time I priced 400A main breakers they were over the moon. If the industry has made huge progress in getting prices down I'd be glad to hear it. I was under the impression that AHJs were granting exceptions to help consumers with the costs, e.g. turning a blind eye to the "single 400A breaker" requirement and still allowing dual 200s. I agree the ranch panel may not be usable at the pole, but possibly at the house (meter bypassed). Commented Mar 19, 2022 at 19:31
  • @Harper-ReinstateMonica -- problem with trying to jumper the meter on a ranch panel at the house is that ranch panels (like all the other meter-mains out there) have a permanent factory N-G bond (i.e. they're labeled as suitable only for use as service equipment). 400A equipment is still somewhat costlier than 2x200A, but the prices also vary wildly depending on whose equipment it is and where you're sourcing it from Commented Mar 19, 2022 at 19:42

Your problem #1: a ranch panel can't feed 400A to the house

Your primary problem is that a 2x200A "ranch panel" configuration can't feed 400A to your house without violating either NEC 225.30 on the number of feeders to a building or NEC 240.8 regarding circuit breakers in parallel. Instead, you'll need to pony up for a 400A, single-disconnect meter-main device; fortunately, since you're in Washington State, we can make a fairly reasonable assumption that your PUD permits EUSERC-compliant meter-mains, which means we don't have to worry about them being particularly picky.

Surveying the field of single-disconnect, 400A meter-mains/meter-panel combinations leads one to Siemens equipment as the least-cost option here, and with that, the MM0202B1400SCS (with a TA2J6500 lug kit) is what fits best into your application. Once you reach the house, you'll still need some form of disconnect there, though, and this can be handled most cleanly by using a non-fused safety switch as the disconnecting means. Once again, Siemens comes through as the least-cost option with the HNF365RA switch when combined with a HN656A neutral kit and HG656A grounding kit. The switch can then feed two 200A main breaker subpanels using 250kcmil conductors in conduit and the 10' feeder tap rules.

Of course, if you have loads outside the house to feed, this gives you more options: limiting the house to 200A lets you use any old "ranch panel" that complies with NEC 2020, such as the Siemens MK0402L1400SCS, while if you need to provide 400A to the house while feeding other loads, a MC2442B1400SDS can do the job, but you'd need to use some 4/0 wire, a pair of ECLK2225 sub-feed lug kits, and a MPDB67423 power distribution block to connect your 500kcmil feeder to the panel in this case.

Your problem #2: that 500kcmil feeder is a size too small for 400A

Your second problem is that the wires you put in are a size too small. Fortunately, that's fixable since you ran it all in conduit. Simply pull the 500kcmil out and replace it with 3x600kcmil Al XHHW-2 with a 1/0 Al XHHW-2 ground. (The local can-pak or scrapyard should be able to accept the old wire if you don't have a use for it, by the way.) If you want to keep the wire in place, the Siemens single-breaker 400A disconnects use industrial-style molded-case breakers that can be "dialed down" to 350A, so that's an option as well.

Your problem #3: putting the disconnects at the house won't work either

Your third and final problem is that your PUD's metering requirements specify that there needs to be a disconnect no more than 15' from the meter. This means that if you don't want to put a meter-main at the pole, you need to install a 400A disconnect (safety switch, most likely) at the pole to serve as that utility required disconnecting means. While it doesn't have to be fused, and Code will let you treat it as a meter disconnect, effectively, instead of as service equipment, it still makes the trough option you're proposing not nearly as attractive as it would be otherwise.

  • So hypothetically would the EATON cooper b-line catalog #324N that i have already combined with Siemens VMS365T 400 Amp 600V Fusible ITE Vacu-Break Panelboard Switch (TK1250-1) and the wire I previously installed going to a properly sized trough with 2 ground rods at the meter as well as 2 ground rods at the house and then feeding my 2/200 amp panels placed within 10 feet of the entrance each with their own 200 amp main breaker be compliant?
    – C streight
    Commented Mar 23, 2022 at 11:36
  • @Cstreight -- the VMS365T is designed to go into a fusible panelboard enclosure, not stand on its own. You'll need to use the HNF365NRA + a HN656 neutral kit (and the OK from your AHJ) at the pole if you want to have the trough + service disconnects at your house Commented Mar 23, 2022 at 11:45
  • @Cstreight -- are the Siemens meter-mains I listed something that's truly unaffordable for you, or are you just afraid of giving up on what you already have and replacing it with something different? Commented Mar 23, 2022 at 11:46
  • I am having trouble finding the unit that meets my situation (MM0202B1400SCS)anyplace that actually has one available i think was my main issue. My situation as it stands is actually pressing enough that i will find a way to afford what it takes to resolve it. I managed to locate the disconnect i listed at a reasonable price (under $800) and so if it was do able to resolve the issue with simply this plus a trough and some ground rods it seemed like the best way out
    – C streight
    Commented Mar 23, 2022 at 14:25
  • I am findingHNF365NA but no HNF365NRA also
    – C streight
    Commented Mar 23, 2022 at 14:35

Another example of Harpers double 200A meter-base. Since the 400A disconnects are SUPER expensive and difficult to find (and they may not be on PUDs list of approved equipment for residential installs!) Biggest advantage of this is that your house panel can be fed from this with its existing panel which becomes a sub panel (you will need to separate grounds from common and possibly run a ground rod at the house) enter image description here

If both feeds are traveling to the house, possibly in the same 3" conduit, be aware of derating requirements for each conductor for running multiple together in a single conduit. Harper can help with discussion about properly grounding these two house panels and separating the neutrals from ground at those panels.

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