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Discussion Starter · #1 · (Edited)
For once I have pictures to go along with the story so I thought I might share. Last night I got to help do something we don't often do where I work. We upgraded the service on each floor....Basically the way it works is there is a 120/208V bus duct running from the basement all the way up to every floor. Each floor has a power take off in a little closet electrical room which contains a 400A main breaker which feeds 4 smaller breakers. Each of the smaller 100A breakers are the main breaker to the 100A sub panels in each of the 4 apartments on the floor.

What was there before were these old ancient c.e.b. (commander) panels with fused disconnects. They had a 400A fused disconnect which was hard bus connected to the power take off, then cabled out the load side to separate bus which the 4 small 100A disconnects stab onto.

What we did was remove the hard bus connection and retrofit in a new eaton pow-r-line c panel. We installed a chunk of bus with 2 mechanical lugs on each phase from the power take off. Then we did dual runs of 3/0 for each phase into the load side of our 400A breaker, reverse feeding the bus for our 100A molded case breakers. We basically just had to undo the old bus remove the old interior, drill holes for the new one, bolt it in, run the 3/0 to feed the main, and re land the existing wiring going out to each apartment.

It was a midnight shutdown to not affect the residents as much, which I don't normally care for, but it was really good experience for me and I quite enjoyed the work. My journeyman showed me how to bend the first 3/0 cable nicely and how much to strip for a dual lugs on the breaker. He landed the existing wires to one of the small 100A breakers then pretty much said have at 'er, make it look good, phasing tape on all cables and I'll be one floor below if you need anything. He supervised me for a few minutes and then took off and I was on my own. He gave me his milwaukee cable cutter to use and showed me a trick to strip the 3/0 with tubing cutters. In the end I think it turned out pretty well for my first go around at residential panel wiring. Passed inspection and everything went well at power up.

Can you guess which breaker my journeyman landed?
 

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Discussion Starter · #3 ·
You will be flogged by ET members for the use of ty raps in a panel!
Oh well. I was ticked we didn't have black tie wraps but life goes on. It was bundled together and tied with some 1910 wire and dried up old electrical tape. I don't see the harm in tie wrapping these wires.
 

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Discussion Starter · #6 ·
HOw are the apartments metered?
No idea at all. I would guess they pay a flat rate for a monthly building fee with their rent, since there is no metering between the bus duct and the dwellings. Don't know though.
 

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Discussion Starter · #8 ·
That is strange . Is that the Canada way ?
Pete
No idea. I am guessing big time here. There are ton's of condo's in Canada, myself and our company have not really been involved in doing a service change for them. Couldn't tell you how they are metered. Usually when we are involved in condo's and high rise's its during construction not after the fact.
 

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Ty Wrapp said:
You will be flogged by ET members for the use of ty raps in a panel!
I'm good with it. It's not like it's any different than the wax string cable lacing methods from way back.
 

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Discussion Starter · #13 ·
Did anyone adjust the trip settings on the main?

BTW, how much power do these apartments use?
Yes, all settings on thermal mag trip units set on site by us per customers co-ordination study! As far as power, we do not look at their metering I could not begin to guess the power consumption or load on each breaker. Our role was strictly retrofitting pow-r-line c interiors into old vintage ceb busway panels. The 100A breakers to each unit are sized to provide overcurrent protection for the existing #3 cable. Even if we stuck an amp clamp on each conductor, it would be a poor indicator, there wouldn't be much load at 3am lol.
 

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It looks fine to me . I love a distribution panel with some room to make terminating less of a chore ! I love when they try to cram 400 amp guts in a 20" wide , 6" deep can , lol !
 

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Discussion Starter · #15 ·
Is that TECK cable coming directly out of a concrete floor?
No it is not. If it was though, I do not think it's a problem. To the best of my knowledge, teck cable is rated for "FT4, -40C, sunlight resistant, direct burial, concrete encasement, for installation in ventilated , non vented and ladder style cable trays in wet or dry exposed or concealed locations. HL rated for Class 1 Zone 1,& 2. Class II Division 1 & 2." It is bx in the photo. Not our cable, not our building, not touched in our work or in our panel, not in scope of work.
 
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