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-   -   #14 rated at 20 amps? (http://www.electriciantalk.com/f31/14-rated-20-amps-48903/)

TPT 01-17-2013 11:10 AM

#14 rated at 20 amps?
 
The latest Canadian electrical code has much higher amperage rating for certain gauges of wire. One example is #14 which is no longer only 15 amps. What's up with this and where would it come into play?

sprdave 01-17-2013 11:56 AM

14-104(2) limits OCD to 15A for #14, so doesn't change much of residential.

But 14-104(1) say except as provided for by other Rules of this Code.
Which would include sections 28 (motors) and 62 (heating), so there is cases you can use the higher ampacity since those sections allow higher OCD.

Also, if you have to derate for conduit fill/temperature, you are starting with a higher ampacity. So if you have to derate a #14 by 80%, you are still left with 16amps.

That's some of the jist, other people can contribute.

Dennis Alwon 01-17-2013 12:32 PM

As in the NEC you use the higher rating for derating so it is helpful there

TPT 01-17-2013 02:22 PM

#14 rated at 20 amps
 
A coworker suggested using #14 NMD90 at the 20 amp. rating but before entering a breaker panel use a junction box and run #12 to the panel. Sounds crazy but maybe not.

sprdave 01-17-2013 02:34 PM

Quote:

Originally Posted by TPT (Post 906222)
A coworker suggested using #14 NMD90 at the 20 amp. rating but before entering a breaker panel use a junction box and run #12 to the panel. Sounds crazy but maybe not.

for what?

TPT 01-17-2013 02:48 PM

#14 rated at 20 amps
 
It could then be terminated under a 20 amp. breaker

sprdave 01-17-2013 03:07 PM

Quote:

Originally Posted by TPT (Post 906231)
It could then be terminated under a 20 amp. breaker

For what though? A motor?

Edit: Do you have to derate or something?

Dennis Alwon 01-17-2013 03:15 PM

Quote:

Originally Posted by TPT (Post 906222)
A coworker suggested using #14 NMD90 at the 20 amp. rating but before entering a breaker panel use a junction box and run #12 to the panel. Sounds crazy but maybe not.

So it sounds like he is trying to cheat the system by hiding the use of 14/2...

ElectricBrent 01-17-2013 04:45 PM

Quote:

Originally Posted by TPT (Post 906231)
It could then be terminated under a 20 amp. breaker

I feel as though you would fail inspection because that 14/2 would still be protected by the 20A OCD, which as stated previously is not allowed for general circuits.

The higher amperage rating allows you to run smaller wires for longer distances when doing voltage drop calculations. It also helps when derating for pipe fill and ambient temperature.

keep in mind that you now have to use the 75 degree column of table 2 in most cases because you have to base the ampacity of your wire on the temperature rating of the device or equipment you are terminating to, as opposed to the rating of the conductors insulation. (i.e. most breakers are rated at 75 deg. c so even if you're using T90 you still have to refer to the 75 deg. column)

360max 01-17-2013 05:23 PM

Quote:

Originally Posted by TPT (Post 906222)
A coworker suggested using #14 NMD90 at the 20 amp. rating but before entering a breaker panel use a junction box and run #12 to the panel. Sounds crazy but maybe not.

......how does he get around the different colored romex during rough in inspection? Not worth it to cut the corner

darren79 01-17-2013 06:15 PM

Quote:

Originally Posted by TPT (Post 906222)
A coworker suggested using #14 NMD90 at the 20 amp. rating but before entering a breaker panel use a junction box and run #12 to the panel. Sounds crazy but maybe not.

#14 wire has to be protected by a 15A breaker. If he does the above he truly is a hack.

Cujo 01-17-2013 06:29 PM

Like others have said, 14-104 prohibits protecting #14 with 20A.

The changes would affect other things such as de-rating for conduit fill, ambient temperature, etc.

sprdave 01-17-2013 07:48 PM

Quote:

Originally Posted by ElectricBrent (Post 906274)
I feel as though you would fail inspection because that 14/2 would still be protected by the 20A OCD, which as stated previously is not allowed for general circuits.

The higher amperage rating allows you to run smaller wires for longer distances when doing voltage drop calculations. It also helps when derating for pipe fill and ambient temperature.

keep in mind that you now have to use the 75 degree column of table 2 in most cases because you have to base the ampacity of your wire on the temperature rating of the device or equipment you are terminating to, as opposed to the rating of the conductors insulation. (i.e. most breakers are rated at 75 deg. c so even if you're using T90 you still have to refer to the 75 deg. column)

Why I was trying to find out what He's trying to do. If general circuits like receptacles it's a no-go. For electric resistance heaters, He could...but also could just run the #14 to the 20A breaker.

It has nothing to do with volt drop calcs. No change there, the copper didn't suddenly become more conductive :no:.

About the only reason I could see using a junction box like this is so you can use the 90degree rating vs being limited to 75degrees by the breaker.

ElectricBrent 01-17-2013 09:23 PM

Quote:

Originally Posted by sprdave (Post 906423)
Why I was trying to find out what He's trying to do. If general circuits like receptacles it's a no-go. For electric resistance heaters, He could...but also could just run the #14 to the 20A breaker.

It has nothing to do with volt drop calcs. No change there, the copper didn't suddenly become more conductive :no:.

About the only reason I could see using a junction box like this is so you can use the 90degree rating vs being limited to 75degrees by the breaker.

There is a change as far as voltage drop is concerned, although not the original intention. When finding the Distance Correction Factor, you are able to use the increased rated amperages in the 2012 code in finding the value to use in the equation. although not always substantial it can reduce the wire by one size in more cases then you might think.:thumbsup:

even if he did this to connect to the breaker, the vast majority of terminals or connection points (motors excluded) are 75 degree rated, so this wouldn't change anything.

daveEM 01-17-2013 09:32 PM

Alberta is fixing this methinks.

Crazy high paid folks trying to justify their wage adding garbage making the code book telephone book size. Then selling another telephone book size explaining their silliness. Charging the same price for a digital copy.

Much like the politicians eh?

KDC 01-17-2013 09:42 PM

The reason is actually pretty simple, to bring the CEC closer in line with the NEC. The NEC has been using those ampacities for a long time.

But just for fun changes read 4-006(1). Means if your main breaker is rated for 75 degrees, you need to use 3/0 for a 200 amp service now.

sprdave 01-17-2013 09:47 PM

Quote:

Originally Posted by ElectricBrent (Post 906581)
There is a change as far as voltage drop is concerned....

I stand corrected...forgot about that :rolleyes:
That's messed up, changing the max amps allowed doesn't change the physical properties...so their numbers were wrong before or now........

sparky250 01-17-2013 09:52 PM

62-114 Overcurrent protection and grouping (see Appendix B)

Subrules
(7) Service, feeder, or branch conductors supplying only fixed resistance heating loads shall be permitted to
have an ampacity less than the rating or setting of the circuit overcurrent protection, provided that their
ampacity is
(a) not less than the load; and
(b) at least 80% of the rating or setting of the circuit overcurrent protection.
(8) Notwithstanding Subrule (7)(b), where 125% of the allowable ampacity of a conductor does not
correspond to a standard rating of the overcurrent device, the next higher standard rating shall be
permitted.

When wiring a residential house with baseboard heaters I use these new amp ratings all the time.

I will load a #14/2 to 20A(4800W max) and terminate to a 25A breaker.
A 12/2 can be loaded to 5760W/24A Max ( 80% ) of a 30A breaker even though
12/2 is now good for 25A

ElectricBrent 01-17-2013 10:51 PM

The majority of the talk has been about the higher ampacities of smaller conductors but has anyone else looked at the changes in wire sizing for underground installations using the IEEE ? In some cases it reqires you to upsize wires 2 or so sizes, which is a big deal when dealing with kcmil sized wires. Funny how these changes were implimented by a group of which 2 of the members have financial interest in wire manufacturing companies.

gottspeed 01-18-2013 04:38 PM

Quote:

Originally Posted by ElectricBrent (Post 906687)
The majority of the talk has been about the higher ampacities of smaller conductors but has anyone else looked at the changes in wire sizing for underground installations using the IEEE ? In some cases it reqires you to upsize wires 2 or so sizes, which is a big deal when dealing with kcmil sized wires. Funny how these changes were implimented by a group of which 2 of the members have financial interest in wire manufacturing companies.


But, its for "Safety". ;)


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