ATS Feeders Cont'd...Any thoughts, please?

[Twoskinsoneman]

As noted in Post #2, the installation is in violation of 240.8.
I agree with this. The circuits are clearly parraled and a violation. If you think about it when the ATS is on utility and power is being used in the house the current if flowing through both panel breakers.

Depending on the arrangement of the condcutors on the load side of the ATS, it may also be in violation of 240.21.
I'm not sure about this... could you elaborate?.

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[augie47]

If one was to correct the "line" side of the ATS to a single 400 amp supply, the two feeders from the "Load" side might or might not meet Code as we have few details.

 

[360Youth]

If one was to correct the "line" side of the ATS to a single 400 amp supply, the two feeders from the "Load" side might or might not meet Code as we have few details.

That was another concern when my boss brought back pics and was describing the setup. The total distance of the furthest load feeder was under 25' so there should not be any tap issues before getting to its first 200 amp OCP. We had thought about changing the two 200 amp outside panels to SE rated 200 amp ATSs, but there was cost and spacing issues.

 

[tkb]

I did state my opinion, that from a code point of view I thought it needed to be changed. Not sure that I would suggest a reinspection unless I thought there was an obvious hazzard. I will only step on somebody else's toes so hard. I have made my share of NEC mistakes in the past (and future )but have always done my best to insure safety.

There is a backfeed hazard.

Meter feeds the top of each 200 amp panel. Feed thru lugs from each panel feeds the utility side of ATS. Load side of ATS feeds to each of the 200 amp panels where it split bolts (or whatever means is under the wrapping of tape) to the house panel feeders. I have not found evidence of back feeding, which was one of our initial concerns, but I did not probe that deep into the entire install. It was clear the elctrician and HO were fine with "as is" so we wrote ourselves off from it and sent a bill for our travel time.

You need to look at this again.

The backfeed is from the feed thru lugs in the first panel to the feed thru lugs in the second panel.
They are connected together on the Normal side of the ATS.
If you open the main CB in panel 1 it would be backfed from panel 2 through the ATS.

I don't see a neutral from the generator. It should be connected to each panel.

 

[SEO]

I agree TKB I mentioned the back feed problem in post #3.

 

[360Youth]

The load side of the ATS is not electricly connected to the outside panels. Line side only.

 

[tkb]

The load side of the ATS is not electricly connected to the outside panels. Line side only.

The line side is the problem.
Also the load side is connected together at the ATS.

 

[RUWired]

I don't see a neutral from the generator. It should be connected to each panel.

the grounded conductor is spliced to the grounded conductor going into the building in each panel., and that becomes a problem because the grounded conductor should be isolated at this point.

I have a list of violation i'd like to add to the post.
(1) 240.8 breakers in parallel,(2)310.4 parallel conductors not the same length,(3)230.74 disconnect needs to disconnect all conductors from the point of supply,(4)300.4/352.46 conduit bushings,(5)annex c.10 conduit fill (6)250.110/352.60 equipment ground missing between enclosures(7)250.24A5 grounded conductor regrounded,(8)250.64E, electrode conductor raceway needs grounding bushing both ends of raceway,(9)225.31 disconnecting means for supply conductors to building(if main lug panel inside building),(10)445.19 ocp required for each feeder,(11)300.11B raceway used as a means for support for other systems,(12) 110.34, no illumination at electrical equipment.

Rick

 

[SEO]

It looks like the mains in the panels are fed directly from the meter. It appears that they are feed thru panels and the feed thru conductors are tied together in the ATS. If you shut one main off both panels would still be energized. It's kind of hard to trace the wiring from the pictures. But that is how I see it.

 

[LarryFine]

I was curious about this. When Thom and I talked on the phone I was curious as to whether this is a parallel feed. They do originate and end at the same point but take different path.

Any thoughts?

Mine is that this is akin to using two 20a 240v circuits to feed a range receptacle.

 

[LarryFine]

With only one 400A feeder, the power is either on or off, so why the ATS?

The ATS is obviously for a genny, and they wanted to power both panels. Two 200a ATS's would have been the way to go.

 

[360Youth]

There is a backfeed hazard.



You need to look at this again.

The backfeed is from the feed thru lugs in the first panel to the feed thru lugs in the second panel.
They are connected together on the Normal side of the ATS.
If you open the main CB in panel 1 it would be backfed from panel 2 through the ATS.

I don't see a neutral from the generator. It should be connected to each panel.

There is that backfeed, but not a backfeed from the generator to utility service.