wire size
- Thread starter jioman
- Start date
- Status
- Location
- Massachusetts
Re: wire size
The temperature rating is of the insulation on the conductor and is a very important aspect to consider.
Consider a 10 AWG copper conductor.
30 amps @ 60 C
35 amps @ 75 C
40 amps @ 90 C
For this fixture the concern is the heat from the lamp damaging the insulation on the conductor.
The temperature rating is of the insulation on the conductor and is a very important aspect to consider.
Consider a 10 AWG copper conductor.
30 amps @ 60 C
35 amps @ 75 C
40 amps @ 90 C
For this fixture the concern is the heat from the lamp damaging the insulation on the conductor.
websparky
Senior Member
- Location
- Cleveland, Ohio
Re: wire size
Very nice answer Bob!
I'm surprised an Instructor would ask this question
Very nice answer Bob!
I'm surprised an Instructor would ask this question
- Location
- Bremerton, Washington
Re: wire size
jioman-wire temperature ratings are one of the first thing an electrician learns. If you are installing a luminaire, er fixture, that requires 90 c wire, and you only have NM, not NM-B, you will eventually cause the NM wire insulation to overheat and fail. You should either install a different fixture, or get a qualified electrician to help. I have had many of my students tell me horror stories about melted and damaged NM in homes with incandescent fixtures due to heat.
jioman-wire temperature ratings are one of the first thing an electrician learns. If you are installing a luminaire, er fixture, that requires 90 c wire, and you only have NM, not NM-B, you will eventually cause the NM wire insulation to overheat and fail. You should either install a different fixture, or get a qualified electrician to help. I have had many of my students tell me horror stories about melted and damaged NM in homes with incandescent fixtures due to heat.
pierre
Senior Member
- Location
- Westchester County, New York
Re: wire size
Lets take this one step further
In the Northeast, we have many old buildings with the clothbraid wiring. Some old ceiling mount fixtures installed for years have literally dried the insulation so much, that when installing a new fixture, the only thing left when pulling the existing fixture down is the copper.
These newer fixtures all require 90 degree C wiring , what do most of you guys do with this situation?
Pierre
Lets take this one step further
In the Northeast, we have many old buildings with the clothbraid wiring. Some old ceiling mount fixtures installed for years have literally dried the insulation so much, that when installing a new fixture, the only thing left when pulling the existing fixture down is the copper.
These newer fixtures all require 90 degree C wiring
, what do most of you guys do with this situation?Pierre
ron
Senior Member
- Location
- New York, 40.7514,-73.9925
Re: wire size
Dave, was your comment needed?
Why can't he ask a question to better understand.
It's hard enough to put the ego aside to ask a question without that sort of stuff.
[ March 23, 2004, 07:05 AM: Message edited by: ron ]
Dave, was your comment needed?
Why can't he ask a question to better understand.
It's hard enough to put the ego aside to ask a question without that sort of stuff.
[ March 23, 2004, 07:05 AM: Message edited by: ron ]
charlie
Senior Member
- Location
- Indianapolis
Re: wire size
Back in the dark ages when I was still working in the trade, I used the insulation stripped from a new piece of the appropriate wire (NM-B, THHN, etc.) I slid this onto the bare wire (stripped as far back into the box as I could get it) and taped it into place in the back of the box. After doing all the conductors in the cable, I would then tape them all together in the same place. At the time, I used Slipknot Gray tape and never had any problems with that method.
Back in the dark ages when I was still working in the trade, I used the insulation stripped from a new piece of the appropriate wire (NM-B, THHN, etc.) I slid this onto the bare wire (stripped as far back into the box as I could get it) and taped it into place in the back of the box. After doing all the conductors in the cable, I would then tape them all together in the same place. At the time, I used Slipknot Gray tape and never had any problems with that method.
websparky
Senior Member
- Location
- Cleveland, Ohio
Re: wire size
You are correct Ron. We should be more accepting of the seemingly obvious new-be questions. Heck, if it weren't for all of the new sign-ups, we old-timers wouldn't have much to argue about!
For all of the newer folks, the bark is much worse than the bite. After all, we were all new-be's at one time!
Darn, can't I have one every now and then?
You are correct Ron. We should be more accepting of the seemingly obvious new-be questions. Heck, if it weren't for all of the new sign-ups, we old-timers wouldn't have much to argue about!
For all of the newer folks, the bark is much worse than the bite. After all, we were all new-be's at one time!
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