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Discussion Starter · #1 ·
Hi all, I'm upgrading a residential panel and am limited by the underground service to 190 amps. Anything wrong with buying a square D qo 200 amp loadcenter with lugs and installing a QOM2175VH 175 main breaker?
Thanks,

Darren
 

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Discussion Starter · #7 ·
The maximum current that an aluminum conductor of a given size and insulation may carry shall be as
follows:
(a) single-conductor and single-conductor metal-sheathed or armoured cable, in a free air run, with a
cable spacing not less than 100% of the larger cable diameter, as specified in Table 3;
(b) one, two, or three conductors in a run of raceway, or 2- or 3-conductor cable, except as indicated in
Subrule (2)(d), as specified in Table 4;
(c) four or more conductors in a run of raceway or cable, as specified in Table 4 with the correction
factors applied as specified in Table 5C;
(d) single-conductor and 2-, 3-, and 4-conductor cables and single-conductor and 2-, 3-, and
4-conductor metal-armoured and metal-sheathed cables, in conductor sizes No. 1/0 AWG and
larger, installed in accordance with configurations described in Diagrams B4-1 to B4-4 in an
underground run, directly buried or in a raceway, as specified in Tables D8A through D15B.


Table D9A
Allowable aluminum conductor ampacities for the
installation configuration of Diagram B4-1
(See Appendix B Note to Rule 4-004.)

1/0 = 190
 

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How on earth (or under earth to be more precise) do you know the service is in compliance of diagram b4-1?? The whole 190mm between each conductor and 915mm below surface?
 

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Discussion Starter · #12 ·
Yeah I don't understand how the ampacity could be the same when one has the wire bundle together and one has them separated.
Pretty sure it's 90degree wire.
 

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Sounds aboooot right then! 190A cable protected with a 175A breaker in a 200A tub.

I honestly don't understand much of that Diagram B4whatever junk.. never used it before.
 

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I'm late to the party on this but would like to throw what I think is correct in:

1) Check with your utility requirements - some may not accept that service size.
2) Residential services in Alberta are controlled by the Electrical Code Regulation (which supersedes CEC and Standata)
3) 1/0 AL is good for 125A for res. applications.

Schedule
1 For the purposes of section 3(a), the Canadian Electrical Code,
Part 1 (Twenty-second edition), being Canadian Standards
Association standard C22.1-12, is varied as follows:
(a) section 4 is amended by adding the following after
Rule 4-004(21):
(22) Notwithstanding Rule 4-006, 3-wire 120/240 V and
120/208 V service conductors for single dwellings, or
feeder conductors supplying single dwelling units of row
housing or apartments and similar buildings and terminating
on equipment having a conductor termination temperature
of not less than 75º C shall be permitted to be sized in
accordance with Table 5E.
(b) the following table is added after Table 5D:
Schedule AR 209/2006

ELECTRICAL CODE REGULATION

3
Table 5E
Minimum permitted size for 3-wire 120/240 V and
120/208 V service conductors for single dwellings,
or feeder conductors supplying single dwelling
units of row housing or apartments and similar
buildings and terminating on equipment having
a conductor termination temperature of
not less than 75º C
(See Rule 4-004 (22))
Size AWG or kcmil
Service or feeder
rating (A)
Copper Aluminum
60 6 6
100 4 2
125 2 1/0
150 1 2/0
200 2/0 4/0
225 3/0 250
300 250 350
400 400 600
 
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