bypass utility meter when power goes off

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hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
nawao said:
The right solution is relocating the meter upstream of the ATS.

This would be the only way this would work, if the POCO allowed it. The drawing shown in the first post will shunt the meter in either position, The normally closed contacts need to feed the line side of the meter, with the normally open contacts tied to the load side of the meter with the panel feed. The common would tie to the 1200 amp distribution panel, besides, a 150 amp contactor enclosure is no smaller than some 150 amp transfer switches, so where is the room gained? Generacs 200 amp single phase transfer switch is around 18" X 24" or so. (go to Generacs web site for exact dimensions)
 

mdshunk

Senior Member
Location
Right here.
LarryFine said:
There is one other idea: contact the POCO field engineers.
Better yet, a real PE. This is a fun brain twister to speculate about, but this is exactly the sort of project that deserves a real engineer's attention.
 

hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
Another thought is, just lease the generator from the poco, here in Georgia, some of the utilities will lease you a generator for backup and co-generation. Have done several of these from a 1500 square foot house to a major distribution center warehouse. No more metering problem.
 

mimo

Member
mdshunk said:
Da-gone, it sure looks like you need an ATS for the load side of each tenant meter instead of my dumb idea below.
Mark,
I'm very limited with the space to install ATS for each unit that means 18 ATS's each of them will be 200A rated that will need a huge room, am I right?
 

mdshunk

Senior Member
Location
Right here.
amingomaa said:
Mark,
I'm very limited with the space to install ATS for each unit that means 18 ATS's each of them will be 200A rated that will need a huge room, am I right?
Hey, I'm not engineer, but that's the only way I see if you want to or need to maintain that metering arrangement. Actually, just one ATS, and a bunch of ASCO 386's as slaves.
 

mimo

Member
Here you gentlemen,
I think that will work, and that relay can be 8"x6" dim. which is not that big size,
 

MIEngineer

Member
Location
Michigan
You will still need to have the N.O. contacts on the line side of the meter. Without it you will still be having some electricity going through the meter and not accomplishing exactly what you require.

I also have reservations that the PoCo will allow you to do this.
 

wireguru

Senior Member
i have a dumb question:

how often does your power go out? By purchasing all this transfer equipment for each apartment, would you ever recoup the cost of it?

If it was me with a generator for infrequent outages of an hour or two here and there, i would just install the thing and let the meters spin and be happy im writing a check for $15 worth of electricty i shouldnt have to pay for vs writing a check for $15,000 for transfer gear for each apartment (i made these numbers up, i have no idea how much all the transfer gear would cost)
 

hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
amingomaa said:
Hello Gentlemen,
Please see attached file with wiring for bypassing the utility meter when the normal power disrupted, and the service goes on the generator, did anyone do that before or I'll be the first, also I'm looking for a relay indicated in that sketch,
Your input really appreciated
Thanks

You are still creating a parallel path, half of the current will flow through the meter and half through the contactor. The meter will still count KWH, just at half the actual amount. You would have to physically remove the meter for this to work. If your bound and determined to do this, Change all of the meters to CT types and wire a relay to short the secondarys of the CT's while the generator is running. This would solve your space problem, as the relays could be 10 or 20 amp.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
hillbilly1 said:
You are still creating a parallel path, half of the current will flow through the meter and half through the contactor.

Change all of the meters to CT types and wire a relay to short the secondarys of the CT's while the generator is running.
Wouldn't that mean half of the current would flow through the CT and half through the relay?
 
amingomaa said:
Hello Gentlemen,
Please see attached file with wiring for bypassing the utility meter when the normal power disrupted, and the service goes on the generator, did anyone do that before or I'll be the first, also I'm looking for a relay indicated in that sketch,
Your input really appreciated
Thanks

I doubt that the Utility would allow you to it this way.

The transfer switch should be AFTER the meter leaving the unmetered utility lines untouched.

Double pole double throw contactor, energized by the utility power for each dwelling unit. When the utility power drops out, it initiates the generator - after a time delay to leave room for the reclosers - and powers the NC set of the contacts.

So you're just going to give free power to the tennats when the utility is off?:) Nice Landlord......
 

dbuckley

Senior Member
The real problem I see is that by just opening the breakers in the utility service distro panel (or causing them to open, eg a short across the contactor coil!) that feed the contactor coils, the cost of tenant electricity can be dramatically reduced. Any PoCo that lets that fly would be certifiably insane. Not to mention that they are paying for all your contactor coil power. Not to mention that when those contactor coils fail through old age the meters will spin more slowly.

I'd also be surprised if they allowed you to supply and maintain the ATS ahead of their meter(s)...

All seems quite odd.
 
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