Bi directional meter

Billy Bob

New member
Location
Arizona
Occupation
Electrician
Hello everybody my name is Bill. My question is I’m installing a second 200 amp feed for an RV garage. currently there is a 200 amp panel for a home I need to bring 400 amp from transformer to home and split to a RV garage. I want to install 400 amp meter section with 2 200. Amp secondary the first 200 amp will be feeding the home panel for the house. The second 200 amp will be feeling the RV garage. my question is having it by directional meter on an existing solar panel arrangement and adding a one-way voltage for RV garage but they will be sharing the 400 amp meter will be by directional current voltage interfere with the one-way voltage for RV garage because they’re sharing the same 400 amp electrical meter
 

winnie

Senior Member
Location
Springfield, MA, USA
Occupation
Electric motor research
There is no such thing as one way voltage.

Electric power flows from sources to loads. Doesn't matter if the meter is bidirectional or not.

If the RV only consumes electricity, then it doesn't matter if the meter is bidirectional.

The only thing a bidirectional meter does is measure correctly when the power flow is from the customer to the utility.

Jon
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
Where is the solar array connected now? (at the house or on the garage?)
(Sometimes, it's better to sketch out a diagram of everything because the words can be unclear.)
I got that it's on the house because the RV garage is being built.

It doesn't really matter to his question though. He wants to have two 200A service disconnects on a 400A service. What he does downstream of one 200A disconnect doesn't affect what he can do downstream of the other per the NEC.
 

Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
Your use of the term "by directional meter" is not clear. Please confirm the following:
  1. You will have have a single 400A service drop and meter from the utility.
  2. You will have 2 x 200A feeders from that service drop, one for the house; one for the RV garage.
  3. You have a Solar PV system, presumably on the house, and presumably with a NEM (Net Energy Metering) contract to where excess energy produced by the Solar PV system is pushed back to the utility through that 400A meter.
  4. You want to know if the Solar PV feed will go only to the house, not the RV garage?
If all of those are true, the answer to #4 is NO. The Solar PV system will just feed your "service", and anything drawing FROM that service will be drawing from the Solar PV, until/unless you need MORE than it can provide, in which case the utility power is pulled in through the service meter. The energy only goes BACK to the utility when your entire service is using LESS energy than the Solar PV system is producing. So at night for example, you will have all of your power coming from the utility (unless you have a battery system). In the middle of the day, if nobody is home and the energy use is minimal, the Solar PV system will be pumping energy back to the utility grid. But if someone is in the RV using energy, the Solar PV energy will go there.

If you WANT them separated, then you would need to have TWO SEPRATE 200A METERS, one for the house that has the NEM contract, then another meter for the RV garage that does not.
 

PaulMmn

Senior Member
Location
Union, KY, USA
Occupation
EIT - Engineer in Training, Lafayette College
...If you WANT them separated, then you would need to have TWO SEPRATE 200A METERS, one for the house that has the NEM contract, then another meter for the RV garage that does not.
And odds are that a 2nd meter will cost another monthly service fee-- if they'll even put a 2nd meter on a single service.
 
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