grounding a service

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Cooper Electrical

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hello I did a service today ....was a 200 amp line to a meter . 200 amp cable to trough where we buged in 2 100 amp lines that went to 2 100 amp panels .The trough was metal so we grounded the trough with the wire from the ground rods and bonded the neutral in the trough. We left the water pipe grounds in the 100 amp panel. Im not sure if thats right or not ....havent done a sevice like this before ...any help would be great
 
I don't have my Code Book handy (it's in he van, and it's raining tonight) but the Neutral is to be bonded at the first disconnect or panel only. You should not have bonded the Neutral again in the trough.
 
What size wire did you use for the water bond, and are the wires in the trough full sized for 200A (i.e. 2/0 or 3/0 copper)? I'm assuming the two panels each have a main and are grouped so this is like a common 400A service (using dual 200's) but a dual 100 setup instead. If you have a 200A main breaker in the meter (meter main combo), then all of your grounding needs to be done from there and not past it.

If the disconnects are a set of two 100A panels (which it sounds like it is), then you can ground from just one panel if the grounds and water bonds are sized from 250.66 for the 200A service entrance wires and as long as the neutral to each panel is sized as large as this too (most likely #4 copper or #2 aluminum).

The neutral is permitted to bond raceways and troughs on the LINE side of the service disconnect. But the trough is service equipment, so you need to use Service bonding rules.
 
I just got done with a similar service. 3phase 240/120V delta with highleg at 400A. We brought in #500s to meter, then inside to 12"X12" trough. Inside trough we used burndy splice blocks to tap off to 3 seperate panels (all 200A MCB) with 3/0 copper. Only one panel was 3 phase, the other 2 were single phase, (omitted high leg). We treated each panel as its own, and bonded the neutral seperately in each panel and sized the GEC according to the 500s. Since the only GE available were 2 ground rods, we only needed to install the required #4 (PoCo sizing) GEC and #1 for water pipe bond.

Gerry

edited for spelling
 
You are permitted to use GEC taps if you want to. In this case, the taps can be size per the panel it is going to rather than the largest service entrance conductor. But for a 100A panel, I wouldn't bother with this approach because you can't go much smaller on the GEC taps unless you use conduit.

I'd just run the GEC's out of the trough or one of the panels, whichever is easier to do.
 
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