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Discussion Starter · #1 ·
Hello everyone, I am located in Ontario Canada. I have my 309a, 442a, master, and contractors license. Most of my experience has been industrial and commercial and some residential. I am starting a one man electrical contractor business and I have a few questions about residential services.
1. For overhead mast(or standpipe) and underground, is everyone using RW90 black/sunlight resistant, #3 AWG copper for 100A and 2/0 for 200A.
2. On an overhead mast, since white RW90 is not sunlight resistant, is a bare neutral the norm or white tape on black wire
3. What is your ground electrode of choice if a metal water pipe system is not available, 2 ground rods interconnected OR 1 electrode plate?
4. If you are performing a service upgrade for someone from, say fuses to breakers and they have a disconnect before their breaker panel, do you prefer removing this disconnect alltogether because your new panel will have a main breaker anyways OR do you leave the old disconnect depending on its condition and just install the new panel with mainbreaker, and essentially have 2 disconnects for your service?

Sorry about the last long winded question. I would very much appreciate your input.

thank you
 

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1. TW75 copper in the sizes you specified except a few are still using 3/0 cu.for a 200A and some I have worked for are using aluminum #2 and #4/0.
2. Aways white conductor, no tape, it is sunlight resistant.
3. Ground plate, can't remember the last time I pounded a ground rod on a res service.
4. Always remove disconnect and have local utility disconnect service or pull meter. Your unlicensed competition won't do this, among other things.

Good luck with your new business.
 

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Discussion Starter · #3 ·
Thank you Mike. In Table 2 of the code book 75C wire is only good for 175amps. That would mean to me that TW75 would have to be 3/0 if used for a 200amp service right?:001_huh:
 

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electricsugarman said:
Thank you Mike. In Table 2 of the code book 75C wire is only good for 175amps. That would mean to me that TW75 would have to be 3/0 if used for a 200amp service right?:001_huh:
††For 3-wire 120/240 V and 120/208 V service conductors for single dwellings, or for feeder conductors supplying single dwelling units of row housing of apartment and similar buildings, and sized in accordance with Rules 8-200(1), 8-200(2), and 8-202(1), the allowable ampacity for sizes No. 6 and No. 2/0 AWG shall be 60 A and 200 A, respectively. In this case, the 5% adjustment of Rule 8-106(1) cannot be applied.

Nevermind though that's for 90 degree
 

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Discussion Starter · #5 ·
Thanks guys for the input. I talked to my supplier to be, and he told me he sells mostly 3/0 copper and 4/0 alum for 200 amp services, and 3awg copper and 2awg alum for 100amp services, RW90.
 

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Discussion Starter · #6 ·
Is there any pros or cons with rw90 vs tw75 for overhead? In my experience Rw90 is a little harder to work with, but you get a -40C handling rating. Tw75 is a little easier to work with but you only get a -10C handling rating. Especially because of this exceptionally cold winter, does anyone forsee any issues using Tw75? Or is there no issue as long as you are not installing the wire at -11C.:)
 

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I've always installed RW90. Been doing it for a long time.

Always copper too. Not sure why on the copper only.
 

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Discussion Starter · #9 ·
Mike, was saying he would always remove the disconnect. The problem I forsee with that is, if its like my home, the main disconnect is in the garage and then feeds down to the basement in rigid conduit to my fuse panel. If i were to remove the disconnect, I would have to reroute all my circuits to a breaker panel in the garage, OR replace the disconnect with a new one (depending on its condition), and replace the fuse panel with a breaker panel exactly where it is. I cant find in the code book where you can't have 2 disconnecting means,- a fused disconnect at service entry point and a main breaker on the new panel downstairs. Does anyone see a problem with this setup?
 

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No , no problem with two disconnects. In that situation you don't really have a choice.
As far as copper or alum choices.
Always check with the supply authority.
Some PUC,s require copper only for service conductors.
Got caught once using alum and they wouldn't hook up even though it passed inspection with ESA.
Good luck with your business!!
 
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