# Low Voltage Transformer



## woodchuck2 (Feb 27, 2008)

Personally i think that call should be up to the inspector or even installer. Who is to say there is an overheat issue with gable vents and an thermostatically controlled gable fan? Just for sake of argument i have seen basement utility rooms where it was 100+ deg in the winter due to the operating heat systems.


----------



## tjbnwi (Feb 24, 2009)

I just looked at a few of the UL listed Class II transformers I have in stock. None say not to install in an attic. None list thermal protection nor is it in the diagram on the box. They all have Class B (130ºC-266ºF) insulation. Even if they had Class A insulation (105ºC-221ºF) insulation this install would not be an issue. 

I've never been in an attic that could boil water just with its ambient air temperature, and that may be still 9ºF below the rating of the insulation. 

Unless you can show me where on the the transformer it stated not install it in an attic, you failed this for no reason at all. 

Thinking about it the transformer has a higher temperature rating than the wire supplying the box. Why didn't you fail the wire in the attic????

Tom


----------



## Inner10 (Mar 12, 2009)

tjbnwi said:


> I just looked at a few of the UL listed Class II transformers I have in stock. None say not to install in an attic. None list thermal protection nor is it in the diagram on the box. They all have Class B (130ºC-266ºF) insulation. Even if they had Class A insulation (105ºC-221ºF) insulation this install would not be an issue.
> 
> I've never been in an attic that could boil water just with its ambient air temperature, and that may be still 9ºF below the rating of the insulation.
> 
> ...


But a 15 dollar door bell kit from hd they have a stamp on the transformer.


----------



## tjbnwi (Feb 24, 2009)

Inner10 said:


> But a 15 dollar door bell kit from hd they have a stamp on the transformer.


We don't know if this was a $15.00 doorbell kit. 

He does not show that in his photo and it is not visible on the shown face. Unless he removed and inspected the unit, and can prove that it was labeled with "Do not install in attic" (which I have never seen). He failed this install for no reason. The burden is on the inspector to prove their cause for failure. 

I'll be by a HD latter, I'll check some of the kits.

Tom


----------



## tjbnwi (Feb 24, 2009)

Here are the install instructions from NewTone. 

http://www.nutone.com/common/productDigitalAssethandler.ashx?id=7f068570-00a9-4e2a-938a-93d923458702

Second page right hand column. There is a big difference between "not recommended" and prohibited. There is nothing stating the transformer "cannot" be installed in an attic. 

Unless the transformer is clearly marked not to be installed in the attic, it is a code compliant install.

Tom


----------



## jar546 (Aug 13, 2013)

In this particular case, the side of the transformer was clearly labeled via embossed into the metal "Do not install in attics" another brand stated "Not to be installed in attics". As long as that is not embossed, it is allowed. But when it is..............

Just making people aware that they need to read the transformer they buy every now and then


----------



## jar546 (Aug 13, 2013)

plummen said:


> The clamps missing and it doesnt look protected are the first things I notice about it.


Internal clamps as stated in previous a previous post.


----------



## jar546 (Aug 13, 2013)

Here is part of the PDF of the installation instructions for "New" installations.


----------



## plummen (Jan 9, 2010)

jar546 said:


> Internal clamps as stated in previous a previous post.


How about a piece of plywood behind it to protect it?


----------



## jar546 (Aug 13, 2013)

plummen said:


> How about a piece of plywood behind it to protect it?


To protect what? Is there a code issue?


----------



## tjbnwi (Feb 24, 2009)

jar546, thank you for the clarification. If those markings were clearly shown in your photo I would have not questioned your decision. 

Tom


----------



## tjbnwi (Feb 24, 2009)

I would just change out the transformer to make this compliant. A lot easier than reworking. 

Tom


----------



## plummen (Jan 9, 2010)

Well youve got romex hanging out sides of box above the rafters that wouldnt take much for somebody to snag and cause problems with.
Youve got a transformer sitting on top of a box thats already sticking up above the rafters which any body could kick/step on after it gets insulation tossed on top of it.
Home owners do also tend to toss boxes and junk in attics without looking at whats sticking out.
You dont consider that an issue?I thought about being a city inspector one time but I know too many hack artists whose work Id never be able to pass just because everybody else does.
I suppose depending on when it was installed we could also say its not a tamper resistant gfci.


----------



## rrk (Apr 22, 2012)

plummen said:


> Well youve got romex hanging out sides of box above the rafters that wouldnt take much for somebody to snag and cause problems with.
> Youve got a transformer sitting on top of a box thats already sticking up above the rafters which any body could kick/step on after it gets insulation tossed on top of it.
> Home owners do also tend to toss boxes and junk in attics without looking at whats sticking out.
> You dont consider that an issue?I thought about being a city inspector one time but I know too many hack artists whose work Id never be able to pass just because everybody else does.
> I suppose depending on when it was installed we could also say its not a tamper resistant gfci.


If there were walk boards in the attic may be a problem, no boards no problem.


----------



## Leo G (May 12, 2005)

plummen said:


> Well youve got romex hanging out sides of box above the rafters that wouldnt take much for somebody to snag and cause problems with.
> Youve got a transformer sitting on top of a box thats already sticking up above the rafters which any body could kick/step on after it gets insulation tossed on top of it.
> Home owners do also tend to toss boxes and junk in attics without looking at whats sticking out.
> You dont consider that an issue?I thought about being a city inspector one time but I know too many hack artists whose work Id never be able to pass just because everybody else does.
> I suppose depending on when it was installed we could also say its not a tamper resistant gfci.


Pretty sure that's a collar tie and not a joist.


----------



## jar546 (Aug 13, 2013)

Leo G said:


> Pretty sure that's a collar tie and not a joist.



You are correct Master Sawdust Producer!


----------



## plummen (Jan 9, 2010)

rrk said:


> If there were walk boards in the attic may be a problem, no boards no problem.


Ive walked in plenty of attics over the years without walk boards in them,its called going from rafter to rafter.:laughing:
Anything can be considered unprotected,it just depends on how the inspector wants to see things on any given day.


----------



## Leo G (May 12, 2005)

Pretty awkward camera position to get into if it was a joist. :laughing:


----------



## plummen (Jan 9, 2010)

jar546 said:


> You are correct Master Sawdust Producer!


I thought joists were under floors and rafters were above ceilings,could very well be a collar tie I cant see the whole attic in picture.
So does that mean that somebody cant still climb over the top of it snagging the wires?
Just saying putting a scrap piece of wood between the collar tie as you carpenters call them and the roof would be a 5 minute job and could save future problems is all.


----------



## jar546 (Aug 13, 2013)

plummen said:


> I thought joists were under floors and rafters were above ceilings,could very well be a collar tie I cant see the whole attic in picture.
> So does that mean that somebody cant still climb over the top of it snagging the wires?
> Just saying putting a scrap piece of wood between the collar tie as you carpenters call them and the roof would be a 5 minute job and could save future problems is all.


Here in lies the problem:

I am here to do an electrical inspection. Other than the wrong transformer for its location, it is a perfectly acceptable installation. It is up in the attic on top of a collar tie, out of the way of everything. I can't make stuff up just because I want to. If it's not in the codes, there is nothing I can do about it. Inspectors are held to a standard.

Yes, "subject to physical damage" is a very subjective issue and you are at the mercy of the inspector or AHJ in the determination of "subject to physical damage" as there are no objective requirements. With that being said, we do not feel as though the installation is subject to physical damage.

If one were a nit-picking anal-renentive inspector with too much time on my hands then maybe they would attempt to write that up. But common sense should prevail. If someone is clumsy enough to trip on it or get their shirt hung up on it then they are a bit of a klutz, aren't they?

The transformer is properly attached to the top of the metal box which acts as a bit of a heat sink, dissipating some of the natural heat build-up of the transformer.

Other than the wrong transformer, I only wish other electricians can make such nice installations.


----------

