Yes to all.

FYI
Are you wiring receptacles? If so, they don’t have a termination temperature so you will have to use the 60 degree column of table 2 as per 4-006.

Also keep in mind grounds, bonds and true neutrals are not counted when derating.

 

Eddy, if I were to use those fancy pigtail plugs with the 6 inch leads, would that eliminate the 60 degree rating for the device then becuae it's a 90 degree rated joint?

I feel like that would be it's own discussion/argument all together lol

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The 90C column is used for derating, not the 75C.

That's why that column even exists.

Start over.

BTW, over cramming a pipe is bad economics. Tight pulls kill electrician careers.

You still can't exceed the termination limits: 75C or 60C.

So you have to look at things twice.

 

ohhhh Canada 🇨🇦

 

^^^This is why you should have put it in the Canadian section. Our rules are different.

Also, I just remembered, There is an Ontario amendment about derating. They do it different than the CEC

 

So the breakers are rated for 75° termination,
the devices (switches and receptacles) are assumed 60° termination,
and the pipe derating is 90° column.

So the derating of .7 using the 90° column would give me 21 amps for the wire derating in the pipe.

60° column is 20 amps, and it's only 15A OCPD.

Does that mean that if I run a pipe from the panel with say 10 conductors, go to a pull box, then drop down with only 2 conductors through a 1/2" or 3/4" pipe to a device I'm good to go? Or do I have to derate the entire circuit?

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Normally you have to use the lowest calculated ampacity for the circuit. Meaning the point where you have 10 ccc in pipe is where the most derating occurs.

 

May want to remember that wire is derated & conduit is sized for pipe fill. Conduit isn't derated.

 

Long day. I meant to say wire/conductor derating... I read that 4 times and didn't catch it, but knew something was off. Thanks.

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I move this to Canadian forum side so others will be aware of it.

 

55 years ago I was a Canadian so I get to post here right Frenchy?

 

old man

 

Isolated ground gets an insulated ground wire (usually green with yellow stripe) back as close to the transformer X0 as you can get it.

If you are getting your IG circuits from a sub panel, install an isolated ground bar in that subpanel and run a wire from it back to the first panel's bar where the system bonding jumper is.

 

Looks like I won't be installing an isolated ground then... I won't be able to pull an additional ground wire from the panel in the unit to where the service enters the strip mall.

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Most strip malls that I work in have a 600 volt feed to the unit, then stepped down to 120/208 or what ever. You can bring your IG to your main panel in the unit as there is a new XO bond there (if in fact that is the case).


Cheers
John

 

I'll find out In 10 minutes when I get there. I don't remember seeing (or hearing) one yesterday.

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Other question I have is, can I install an isolated ground outlet, and just run the isolated ground the the ground bus in the panel of the store? I'm wondering if it's okay to do it this way. (The boss has never had to install an isolated ground receptical... changed/replaced yes just not new lines). I'm just worried about interference or whatever for the cash register area (job is T&M so not worried about the extra cost to do it) or am I just over thinking this?

Sorry, slight hijack here... but has anyone out there ever ran into a problem that was solved with an IG plug? Personally I haven't heard of an IG plug doing anything useful. I see old school engineers and misguided I/T staff call for them but I doubt they understand why.

I have a feeling that this was left over from when electronics were kinda junky and more prone to interference issues. I don't think modern electronics suffer from any sensitivity like this. Can anyone make a good argument for the use of an IG plug in any situation?

 

I got one.

I did a job that had white walls with orange accents and the orange IG receptacles matched really well 👍

 

Anytime im doing more than a circuit or two of pipe work i usually run 1"
1" can fit max 25 #12 t90
24 #12 derate to 21A and can be used for 20A ccts.
the 25th wire is a green #12 so that if i have to pull 10's for something far or larger im good to go.
When pulling in you can usually get it done with two or three pulls and with that many spools if you pull a #14 green it will curl at a different twist than the #12s and cause spaghetti.
1" is the sweet spot, but if you actually plan to fill it go larger.
Ontario only, the bulletin and following the math is worth the time.

 

We're running all 1" and 3/4" on this job. I brought my 1/2" bender, but we aren't even buying 1/2" conduit haha

We use RW90, not T90

We are running oversized conduits for future additions that we are predicting will happen within a few months.

Where are you getting 25 conductors in a conduit from? CEC Table 6K says 22 conductors in a 27mm conduit max... see attached photo

 

table 6 is based on the inside diameter of the smallest type of conduit as a general lookup tool. Go calculate fill with table 9 and 10a

 

I forgot about that! Just did the math for my RW90 solid #12 and it comes up to 21.5 conductors for a 1" EMT. The table says 16! That means we are over building more than we thought.

Oh well, makes for easy pulls.

 

I usually go with max 6 ckts per 3/4C with #12. Over 100’ use #10. Known heavy loads this won’t apply to. Most ckts are low amperage


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It's funny, we are going to have a 1" EMT with only 11 conductors. 4 hoists (2 conductors each) and 2 receptacles on their own breakers.

The run will be downsized to 3/4" after the second hoist, leaving us with only 7 conductors.

Nothing will be more than 100' I don't think. Maybe closer to 80'. We will find out when the conduit gets installed. We are stuck dead in the water without any ladders or a lift... their lift is too short, and their ladders belong in the garbage... Tuesday I'm getting a shipment of ladders.