bypass utility meter when power goes off

[mimo]

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

 

[mdshunk]

You call that a utility meter, but your drawing seems to indicate that it's a submeter. Is that the case, or is this cold sequence metering? In any event, that relay is pretty easy to source from any of a number of manufacturers. How many amps does it need to handle? Is that a PoCo drawing? If so, I think that relay will need to be in a sealable enclosure.

 

[benaround]

Why are those n.c. contacts running from A phase to B phase ? Looks like

a power outage in the making.

 

[mdshunk]

Why are those n.c. contacts running from A phase to B phase ? Looks like

a power outage in the making.

"But I wired it just like the drawing". :grin:

Sharp eye, benaround. I didn't happen to notice that, but I wasn't looking in detail. I'm certain that's just a simple goof-up. I can just see the change order. "Would you like your equipment to trip the breaker every time. Check one. Yes or no."

 

[mimo]

Thank you gentlemen for your input, I just noticed that the nc contacted are wrong between phases A and B that's because I was in a rush to go on Friday
, However yes this will be a utility meter and the amp rating should be up to 150A, the good news is that can be done thanks Mark
Will you by any chance suggest some manufactures for that relay.

 

[mdshunk]

Will you by any chance suggest some manufactures for that relay.

Something like an ASCO 386 would do the trick. Basically it's the guts of a DPDT automatic transfer relay that you can remote control like you want to.


EDIT... nevermind

 

[mdshunk]

Something like an ASCO 386 would do the trick. Basically it's the guts of a DPDT automatic transfer relay that you can remote control like you want to.

 

[benaround]

amingomaa, Why not relocate the meter upstream of the ATS ?

To me it looks like you are " jumping out the meter " , the POCO calls it

stealing electricity. Also when the contacts change state, nothing different

really happens, rushing is not your forte'

 

[nafis]

explain please

explain please

hi every one

can you guys tell me whats wrong with N.c , i am just trying to understand .

 

[mimo]

Why not relocate the meter upstream of the ATS ?
To me it looks like you are " jumping out the meter " , the POCO calls it
stealing electricity. Also when the contacts change state, nothing different

by relocating the meter upstream of he ATS that will mean using 12 ATS's because this building has 12 apartment, and that's not stealing electricity because I'm trying not to pay the utility when the utility servise disrupted only..

 

[ron]

nafis,
During regular operation power on the line side of the meter is being transposed on the load side (Phase A gets connected to B and then B to A).
Same during generator operation.
So essentially a phase to phase short circuit.

It is hard for me to believe that the utility would allow you to jump out their meter. Then you could steal power all day long (half through the meter and half through the bypass) in either mode. The meter will always pass power through as you are not opening that portion of the circuit.

 

[hillbilly1]

I know what you are trying to accomplish, but if I was the utility I would not allow it, as someone can easily bypass the meters using the generator control wiring. If these are landlord billed submetering I would leave the meters in the circuit to help pay for the cost of running the genset. Generac has a 150 amp transfer switch (probally made by Asco) that all is needed to transfer is a 12 vdc signal from the generator.

 

[hillbilly1]

by relocating the meter upstream of he ATS that will mean using 12 ATS's because this building has 12 apartment, and that's not stealing electricity because I'm trying not to pay the utility when the utility servise disrupted only..[/QUOTE]

Will you not be using 12 contactors anyway? Or not all tennants will be receiving generator power? The generac ats switch runs about $600, a 150 amp DPDT contactor couldn't be any cheaper.

 

[hillbilly1]

After looking at the drawing again, you are actually creating a parallel path for the current ,and would only shunt 1/2 of the current thru the contactor and the other half thru the meter, so this will not do what you want anyway.

 

[mimo]

After looking at the drawing again, you are actually creating a parallel path for the current ,and would only shunt 1/2 of the current thru the contactor and the other half thru the meter, so this will not do what you want anyway.

the wiring around the meter is not right i'm awar of that, but the concept is right to use two N.O. contacts and two N.C. contacts around the meter to bypass it only when the gen. kicks on, This building will have 12-18 apartment and i'm trying to avoide using 12-18 ATS's in a smale size elec. room

 

[mrtoy]

I don't believe they would allow this.The N/C contacts by pass the meter in normal operation.

 

[nawao]

The right solution is relocating the meter upstream of the ATS.

 

[jghrist]

It may not be your intent to steal energy, but you could easily do it with this arrangement. I doubt if the utility would approve of this arrangement. A better solution would be to have metering on the generator and on the utility ahead of the ATS and use the existing meters as sub-metering. Then the generator owner could be compensated for fuel use instead of the apartment renters getting free energy during a utility outage.

 

[mdshunk]

Put your ATS on the MDP feeder instead of each tenant feeder. Duplicate the MDP for the generator. You'd be toggling between the PoCo MDP and your own generator MDP with the ATS. Tie your generator MDP tenant feeders in on the load side each respective PoCo meter.

 

[mdshunk]

This is what I had in mind, but it wasn't until I drew it that I realized that it would be a poor design. The high-current using tenants would be spinning the meters ever so slowly backwards of the low current using tenants.

Da-gone, it sure looks like you need an ATS for the load side of each tenant meter instead of my dumb idea below.