From previous threads started on this topic it has been determined that for each temperature increase there is an H in the symbolism (tw=60)(thw=75c)(thhn=90c)and in homes built before 90c wire was installed lets say Mr Dough wants a new light installed and the light says MUST USE 90c WIRE; now is that for the heat output by the bulbs or is it due to the draw there would be on the wire; If it is a heat thing then would additional insulation help or would a pigtail on a pc of 90c wire be sufficient; But if it a draw on the wire then would a rerun of the circuit be warranted (just for 1 lite?)
90c Lights on 60c wire
- Thread starter rrrusty
- Start date
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tonyi
Senior Member
Re: 90c Lights on 60c wire
IMO, as a practical matter everything in the box will get hot when some idiot puts 150W bulbs in a 60W bulb rated fixture (which is probably the REAL reason behind these 90 degree restrictions!), so a pigtail within the box doesn't really do a whole lot. Add to this that a lot of these older places (and a lot of newer ones) are using that same box as a general purpose junction to split multiwire homeruns so something fairly unrelated to the light may be heating up the box environment too..and being overheated by said idiots overbulbing the fixture.
IMO, as a practical matter everything in the box will get hot when some idiot puts 150W bulbs in a 60W bulb rated fixture (which is probably the REAL reason behind these 90 degree restrictions!), so a pigtail within the box doesn't really do a whole lot. Add to this that a lot of these older places (and a lot of newer ones) are using that same box as a general purpose junction to split multiwire homeruns so something fairly unrelated to the light may be heating up the box environment too..and being overheated by said idiots overbulbing the fixture.
pierre
Senior Member
- Location
- Westchester County, New York
Re: 90c Lights on 60c wire
Rusty
This is a sore subject in our jurisdiction, and Tonyi has really said what needs to be addressed. I am myself trying to get an answer from the NFPA and UL on this matter. When I have received whatever they are going to say, I will let you know.
This is an interesting issue in the fact that some of these new 'contractor' fixtures are listed, but very, very cheap and required to be lamped with 60 watt lamps. We all know that we are not responsible for what happens after we leave the finished job, but we also know the reality is we will be involved in a mess if there is a problem later with this installation. The manufacturers have really protected themselves, what about the contractor?
Pierre
Rusty
This is a sore subject in our jurisdiction, and Tonyi has really said what needs to be addressed. I am myself trying to get an answer from the NFPA and UL on this matter. When I have received whatever they are going to say, I will let you know.
This is an interesting issue in the fact that some of these new 'contractor' fixtures are listed, but very, very cheap and required to be lamped with 60 watt lamps. We all know that we are not responsible for what happens after we leave the finished job, but we also know the reality is we will be involved in a mess if there is a problem later with this installation. The manufacturers have really protected themselves, what about the contractor?
Pierre
Re: 90c Lights on 60c wire
Heat is the problem. I recently replaced an enclosed bulb lighting fixture that had literally fallen off of the ceiling. It had gotten so hot that the box (old plastic) had turned the support screws loose. This was the first floor of a two story. The old nm cable was in sad shape in the box too. My solution was to cut a hole beside the existing box that was big enough to slide a JB thru. Then I took off and replaced the damaged box with metal. I then cut back the old nm and spliced on new 90C cable inside the JB, pushed it into the ceiling, and fed my new pigtail into the new ceiling box. Luckily the light fixture was big enough (14" dia.)to cover it all up. The JB is accessible when the fixture is removed.
I don't recommend enclosed fixtures to my customers. Usually the mention of excessive heat and melted wiring is enough to change their mind.
Heat is the problem. I recently replaced an enclosed bulb lighting fixture that had literally fallen off of the ceiling. It had gotten so hot that the box (old plastic) had turned the support screws loose. This was the first floor of a two story. The old nm cable was in sad shape in the box too. My solution was to cut a hole beside the existing box that was big enough to slide a JB thru. Then I took off and replaced the damaged box with metal. I then cut back the old nm and spliced on new 90C cable inside the JB, pushed it into the ceiling, and fed my new pigtail into the new ceiling box. Luckily the light fixture was big enough (14" dia.)to cover it all up. The JB is accessible when the fixture is removed.
I don't recommend enclosed fixtures to my customers. Usually the mention of excessive heat and melted wiring is enough to change their mind.
tonyi
Senior Member
Re: 90c Lights on 60c wire
Short of pulling in all new, the side-by-side JB's ploy is probably about as good as you can do and still CYA when the bozo overlamps and burns his place down ;->
I've done the same thing. If the fixture base isn't big enough to cover both, you could just go a few feet away and mount something like a CO or heat detector on the new JB so it doesn't look so much like a patch/goof<g>.
Short of pulling in all new, the side-by-side JB's ploy is probably about as good as you can do and still CYA when the bozo overlamps and burns his place down ;->
I've done the same thing. If the fixture base isn't big enough to cover both, you could just go a few feet away and mount something like a CO or heat detector on the new JB so it doesn't look so much like a patch/goof<g>.
Re: 90c Lights on 60c wire
I always try to buy antique lighting fixtures.
The question in some of these 90deg requirements is that it appears on new chandeliers also, on these fixtures the lamps are remote from the outlet box and wouldn't directly (besides total lamp wattage) add heating effects to the wiring system.
This has become a generic label on most new fixtures, some with merit, some not.
Roger
[ September 26, 2003, 03:14 PM: Message edited by: roger ]
I always try to buy antique lighting fixtures.
The question in some of these 90deg requirements is that it appears on new chandeliers also, on these fixtures the lamps are remote from the outlet box and wouldn't directly (besides total lamp wattage) add heating effects to the wiring system.
This has become a generic label on most new fixtures, some with merit, some not.
Roger
[ September 26, 2003, 03:14 PM: Message edited by: roger ]
Re: 90c Lights on 60c wire
This requirement for 90? insulation is due to insulation. This development started after the energy conservation agency recommended insulation be added to the attic space of dwellings. This insulation was usually the blown in type. It covers all the light outlet boxes, trapping heat.
The heat is communicated to the box, and the other wiring, from the conductors attached to the lampholder of the light. The wattage of the lamp is important, even though the approved size will create excessive heat.
The use of plastic boxes with no vent holes is also a factor in the heat containment.
In my home I use the low wattage florescent lamps in any fixture with the lampholder close to the ceiling.
Insulation will prevent the heat of the glass envelope from entering the box, but it will only have a negative effect on the conductor communicated heat.
[ September 26, 2003, 04:53 PM: Message edited by: bennie ]
This requirement for 90? insulation is due to insulation. This development started after the energy conservation agency recommended insulation be added to the attic space of dwellings. This insulation was usually the blown in type. It covers all the light outlet boxes, trapping heat.
The heat is communicated to the box, and the other wiring, from the conductors attached to the lampholder of the light. The wattage of the lamp is important, even though the approved size will create excessive heat.
The use of plastic boxes with no vent holes is also a factor in the heat containment.
In my home I use the low wattage florescent lamps in any fixture with the lampholder close to the ceiling.
Insulation will prevent the heat of the glass envelope from entering the box, but it will only have a negative effect on the conductor communicated heat.
[ September 26, 2003, 04:53 PM: Message edited by: bennie ]
G
Guest
Guest
Re: 90c Lights on 60c wire
As a sidebar: Recessed cans cannot be within 12" of old low-temp wire. You need to keep a separation between the can and the secondary J-box.
410.67(B)(C).
As a sidebar: Recessed cans cannot be within 12" of old low-temp wire. You need to keep a separation between the can and the secondary J-box.
410.67(B)(C).
tonyi
Senior Member
Re: 90c Lights on 60c wire
I put some 75W 3-bulb enclosed fixtures in my mom's kitchen recently - and put the 75W equivalent flourescents in'em. The old 2-bulb open fixtures with incandescents were running a lot hotter than these 3's with the compacts.
The power saving is nice of course, but these things dramatically cut down on the heat getting dumped into the wire in the boxs.
I put some 75W 3-bulb enclosed fixtures in my mom's kitchen recently - and put the 75W equivalent flourescents in'em. The old 2-bulb open fixtures with incandescents were running a lot hotter than these 3's with the compacts.
The power saving is nice of course, but these things dramatically cut down on the heat getting dumped into the wire in the boxs.
Re: 90c Lights on 60c wire
410.67 Wiring.
(A) General. Conductors that have insulation suitable for the temperature encountered shall be used.
(B) Circuit Conductors. Branch-circuit conductors that have an insulation suitable for the temperature encountered shall be permitted to terminate in the luminaire (fixture).
(C) Tap Conductors. Tap conductors of a type suitable for the temperature encountered shall be permitted to run from the luminaire (fixture) terminal connection to an outlet box placed at least 300 mm (1 ft) from the luminaire (fixture). Such tap conductors shall be in suitable raceway or Type AC or MC cable of at least 450 mm (18 in.) but not more than 1.8 m (6 ft) in length.
The higher temperature tap conductors must be in a tap box placed 12 inches away from the fixture and the fixture must be fed from tap box to fixture by a whip that is at least 18 inches to six feet long
410.67 Wiring.
(A) General. Conductors that have insulation suitable for the temperature encountered shall be used.
(B) Circuit Conductors. Branch-circuit conductors that have an insulation suitable for the temperature encountered shall be permitted to terminate in the luminaire (fixture).
(C) Tap Conductors. Tap conductors of a type suitable for the temperature encountered shall be permitted to run from the luminaire (fixture) terminal connection to an outlet box placed at least 300 mm (1 ft) from the luminaire (fixture). Such tap conductors shall be in suitable raceway or Type AC or MC cable of at least 450 mm (18 in.) but not more than 1.8 m (6 ft) in length.
The higher temperature tap conductors must be in a tap box placed 12 inches away from the fixture and the fixture must be fed from tap box to fixture by a whip that is at least 18 inches to six feet long
electricmanscott
Senior Member
- Location
- Boston, MA
Re: 90c Lights on 60c wire
Tonyi, the people that overlamp are not "idiots" and "bozos" They are average people that do not know ant better.
Tonyi, the people that overlamp are not "idiots" and "bozos" They are average people that do not know ant better.
tonyi
Senior Member
Re: 90c Lights on 60c wire
I dunno...the fixtures are all labeled pretty clearly, even embossed right into the metal shell on some.
I guess some people really can't change a light bulb without screwing it up ;->
Here's an idea - the lamp and bulb manufacturers should start making keyed fixtures that can't be overlamped. Something along the lines of a type S fuse socket.
I dunno...the fixtures are all labeled pretty clearly, even embossed right into the metal shell on some.
I guess some people really can't change a light bulb without screwing it up ;->
Here's an idea - the lamp and bulb manufacturers should start making keyed fixtures that can't be overlamped. Something along the lines of a type S fuse socket.
Re: 90c Lights on 60c wire
At one time lamps were of a size difference that larger lamps would not fit in the confines of most fixtures. Now the 100 watt is about the same as a 40 watt, in physical size.
An A19 is 2 and 3/8 inches in diameter, regardless of the watt rating.
An A19 can be up to 100 watts and fit into a lampholder for 60 watt maximum lamps. The next size A21 goes to 150 watts. A 300 watt lamp can fit the standard Edison base.
At one time lamps were of a size difference that larger lamps would not fit in the confines of most fixtures. Now the 100 watt is about the same as a 40 watt, in physical size.
An A19 is 2 and 3/8 inches in diameter, regardless of the watt rating.
An A19 can be up to 100 watts and fit into a lampholder for 60 watt maximum lamps. The next size A21 goes to 150 watts. A 300 watt lamp can fit the standard Edison base.
G
Guest
Guest
Re: 90c Lights on 60c wire
It seems like many older enclosed fixtures maxed out at 60W. With the better wire many now max out at 75W or 100W. For safety reason it would make sense if anything over 100W had to be say mogul base. Or, start a whole new base-standard based on maxiumum wattage permitted by the fixture.
It's really not as easy as it used to be. Now with cans the label lists a dozen different combinations of lamp style vs. wattage. The watts can vary depending on the style of lamp.
That's mostly why the fuse panel system got trashed by the insurance companies-- too many people overfusing-- putting 20's on a 15 circuit, etc.
Safety dictates making it fool-proof.
It seems like many older enclosed fixtures maxed out at 60W. With the better wire many now max out at 75W or 100W. For safety reason it would make sense if anything over 100W had to be say mogul base. Or, start a whole new base-standard based on maxiumum wattage permitted by the fixture.
It's really not as easy as it used to be. Now with cans the label lists a dozen different combinations of lamp style vs. wattage. The watts can vary depending on the style of lamp.
That's mostly why the fuse panel system got trashed by the insurance companies-- too many people overfusing-- putting 20's on a 15 circuit, etc.
Safety dictates making it fool-proof.
- Location
- Massachusetts
Re: 90c Lights on 60c wire
You do lose the focusing feature though.
Bennie or anyone have you seen/used the new mini mag lights with the LEDs, nice and bright and the batteries (AAs) last much longer.
You do lose the focusing feature though.
romex jockey
Senior Member
- Location
- Vermont
- Occupation
- electrician
Re: 90c Lights on 60c wire
David Shapiro on page 206 of Electrical Contractor touches on the angst most field electricians share on this topic
I've read of remedies of all sorts, some quite ingenious really
yet the bottom line is that this entire fascade exists to market cheap fixtures, and the 90 deg disclaimer, along with anything insinuating a call to the 'qualified' simply lays the whole deal on the trade.
think about it, the general public doesn't really subscribe to a C temp rating here do they?
smoke and mirrors folks....
my advice, start hammering those orginizations that supposively uphold our trade to get this albatross off our necks
read the disclaimer word for word, one can only be held to the legalese as such, same as the NEC
you just might note a loophole
example, 410.67(B) 'in the luminare'
David Shapiro on page 206 of Electrical Contractor touches on the angst most field electricians share on this topic
I've read of remedies of all sorts, some quite ingenious really
yet the bottom line is that this entire fascade exists to market cheap fixtures, and the 90 deg disclaimer, along with anything insinuating a call to the 'qualified' simply lays the whole deal on the trade.
think about it, the general public doesn't really subscribe to a C temp rating here do they?
smoke and mirrors folks....
my advice, start hammering those orginizations that supposively uphold our trade to get this albatross off our necks
read the disclaimer word for word, one can only be held to the legalese as such, same as the NEC
you just might note a loophole
example, 410.67(B) 'in the luminare'
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