# Weird 400A service entrance



## Gizmot (Dec 30, 2019)

House build around 2008 in Canada. Friend asked and I could not answer. I deal with MW level gear and have no idea about the standard residential cost minimizing tricks. Asked a dozen or so power gen sparkies and they are all in the same situation. Guys that deal with residential stuff all told me that "should open up and see".



- 400A underground service goes to
- 400A Siemens ID225 main disconnect goes to
- 2x mystery 30"x30" panels goes to
- 1 large gutter box, each mystery panel is feeding 3 wires to common lugs, lugs are then immediately split again and goes to
-2x 40 poles 150A breaker panels and 1x 125 fused disconnect.
- 1.5"ish PVC conduit is branched off from 1 of the mystery panel and goes to the outside smart meter (Focus RXRe)


Question is: why split the main 400A into he 2 mystery box only to merge them later in the gutter box? Why panels that big?



My first guess was the the mystery panels used to house 2 separate meters in order to lower energy cost. That's probably wrong since the covers are originals.
Now, PVC conduit going to the meter is to small to carry back and forth some 400A wiring.
Would love to open it up but sealing and unsealing permit is about 800$...


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## CoolWill (Jan 5, 2019)

Sounds like a 400 amp CT setup to me. You guys don't use CTs at the megawatt level? A m


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## Gizmot (Dec 30, 2019)

yeah, I just don't get why you would do this in a residential setup.
The answer has to be standard equipment usually paired with a 100-200A service entrance, I just don't understand where the limitation is.


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## CoolWill (Jan 5, 2019)

Gizmot said:


> yeah, I just don't get why you would do this in a residential setup.
> The answer has to be standard equipment usually paired with a 100-200A service entrance, I just don't understand where the limitation is.


There are plenty of 400 amp CTs in residential and commercial services with two 200 amp panels inside. The limitation is 400 amps.


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## B-Nabs (Jun 4, 2014)

I would say one of those boxes is for sure a CT, not sure why there would be two boxes though. 

Sent from my SM-G975W using Tapatalk


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## Gizmot (Dec 30, 2019)

Made a sketch, thats not where I'm confused.
Main disconnect goes to 2 CT boxes (?), then BOTH CT boxes get MERGED together again on common lugs in the guter box. Then guter box is connected to all "3" panels.
Why would you purposely split the power to 2 CT boxes to merged them again just after? 

A) I dont see 2x 200A CT with panels with conduit being cheaper than a single 400A. B) Split the power in 2, use a single 200A CT and multiply the resulting current by 2. If so, why 2 larges 30x30 panels?


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## HackWork (Oct 2, 2009)

So it costs $800 to check for a loose connection on a residential service?


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## Gizmot (Dec 30, 2019)

both 30x30 panels, main disconnect and outside meter all sealed up with serialized tags and thus on the provider side. Fixing a loose connection on that side would be on the provider so no.


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## Cow (Jan 16, 2008)

Gizmot said:


> Would love to open it up but sealing and unsealing permit is about 800$...


Is that what the power co charges you?

Or is that the electrical inspectors office?


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## glen1971 (Oct 10, 2012)

Is it set up for a back-up generator, or future solar install?

I'm guessing they are both CT cabinets, as others have said. Are the conductors from the main to the CT's ran as parallel? Or can you tell? Installing electrician ran one set to each CT, so 4 CT's instead of 2?

Without seeing inside the 30"x30" boxes, you're guess is as good as mine.


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## Gizmot (Dec 30, 2019)

Cow said:


> Is that what the power co charges you?
> 
> Or is that the electrical inspectors office?



power co, its a bit cheaper than 800$ but essentially you need permit first where they show up, then they need to come back again to re-seal the panels themselves. There is obviously some loopholes but not worth it for curiosity sake.


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## Gizmot (Dec 30, 2019)

^
|
|

(Cannot post picture but you can follow the broken link in my post #6 above for a schematic)


Only true guess is looking inside the gutter box. 2 conduits coming in with each 3 conductors. I'm assuming from each CT

Since there is 2 conduits going to the left CT, I'm assuming its splitting at the main disconnect and looping to the left. Guess I need to find the Focus meter manual.


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## Gizmot (Dec 30, 2019)

glen1971 said:


> Is it set up for a back-up generator, or future solar install?



nope, nothing unusual except for the ludicrous amount of panel space


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## gpop (May 14, 2018)

one box is probably a surge suppressor and its tied directly to the common lugs


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## Gizmot (Dec 30, 2019)

gpop said:


> one box is probably a surge suppressor and its tied directly to the common lugs



but if that was the case, the surge suppressor would not be in an enclosure with a utility security tag.


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## gpop (May 14, 2018)

Gizmot said:


> but if that was the case, the surge suppressor would not be in an enclosure with a utility security tag.


why not. 

I pay poco (monthly) for surge suppression and insurance against surge damage. I can not access the unit (i think mine is behind the meter). On a CT meter the surge would have to be mounted somewhere so maybe its in the box.


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## FishinElectrcian (Jul 18, 2019)

Hey so.. Anything 300A + needs CT's. One way this is designated is with hydro tag, at least in BC, orange tag on the meter is a CT somewhere, blue tag is regular meter. Unless the tag is over 20yrsold then there was a mix of orange and steel. Usually there's a warning posted, since if you pull the meter on a CT setup it will explode in your face if you don't short the CT's out first. 

Mystery boxes.. I would guess one houses a CT, it's also possible with your setup that someone might be tapping down the conductor size to something smaller to fit in the panel lugs, that might be a bit of a reach with the splitter box. It's also possible that one box is CT's and the other is the jumper box with little knife switches to short out the CT's. I've seen that before.


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