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Heated Shower Mirror #201778 06/23/11 04:07 PM
Joined: Jun 2011
Posts: 3
P
ptfw30 Offline OP
New Member
Hello all,
Just got a low voltage anti-fog shower mirror. Instructions say to place a box behind the mirror. But then the box would be burried. I have the transformer in a dry location on a switched outlet and wanted to run the wires directly to the dry location? In other words no box directly behind the mirror.

Thanks in advance...

2017 / 2014 NEC & Related Books and Study Guides
Re: Heated Shower Mirror [Re: ptfw30] #201780 06/23/11 04:26 PM
Joined: Jan 2005
Posts: 5,316
renosteinke Offline
Cat Servant
Member
It would be a major help to have the instructions available for review.

Here is a link to one such product: http://www.plumbingstore.com/clear-mirror-installation.html#shower

UL lising or not, I see this as a code-compliant installation only if the mirror is in a damp location (over the sink, not in the shower), and the mirror is removable.

Note that the instructions are silent as to reattaching the mirror to the wall. IMO, the common practice of attaching the mirror with caulk would not be allowed, as it would make the box inacessable.

The access issue remains the same whether the wire are low voltage or line voltage.

IMO, the mirror needs to be GFCI protected. It is common for bath lights to NOT be GFCI protected. This sets the stage for an unprotected mirror, as they want you to tie into the light feed.

Re: Heated Shower Mirror [Re: ptfw30] #201781 06/23/11 05:41 PM
Joined: Jun 2011
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ptfw30 Offline OP
New Member
Its the same mirror...

* Mirror is in a wet location (in shower)
* Mirror is glued into place, per the instructions.
* Mirror is powered by a remote x-fmr (in dry and accessible location)
* I will be using a GFCI breaker for this circuit


I think I will be running the wires to the dry location and box it there. That way its accessible, dry and boxed.

Last edited by ptfw30; 06/23/11 05:42 PM.
Re: Heated Shower Mirror [Re: ptfw30] #201783 06/23/11 07:41 PM
Joined: Apr 2002
Posts: 7,105
HotLine1 Offline
Member
ptfw:
First, If no one said it yet...Welcome to ECN forums!!

What you last said...

"* Mirror is in a wet location (in shower)
* Mirror is glued into place, per the instructions.
* Mirror is powered by a remote x-fmr (in dry and accessible location)
* I will be using a GFCI breaker for this circuit


I think I will be running the wires to the dry location and box it there. That way its accessible, dry and boxed."

Sounds like a plan to me.






John
Re: Heated Shower Mirror [Re: HotLine1] #201790 06/23/11 10:31 PM
Joined: Oct 2000
Posts: 5,373
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sparky Offline
Member
just an aside here, what can be expected of a line side gfi meant to protect xfomer secondaries?

~S~

Re: Heated Shower Mirror [Re: ptfw30] #201792 06/23/11 11:43 PM
Joined: Jun 2011
Posts: 3
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ptfw30 Offline OP
New Member
HotLine1 wrote...
"ptfw:
First, If no one said it yet...Welcome to ECN forums!!"




THANKS for the welcome and the reply!!

Sparky, you bring up a good point. I would imagine that since the GFCI detects unbalanced return current on the neutral, that any 24 volt secondary anomaly would not be reliably interrupted. A voltage to human contact would probably just look like a bigger load to the primary side, and would not necessarily trip the GFCI.

I do have lighting and switches in or near a wet area, and that is mostly why I have the GFCI.

Last edited by ptfw30; 06/23/11 11:44 PM.
Re: Heated Shower Mirror [Re: ptfw30] #201795 06/24/11 07:43 AM
Joined: Oct 2000
Posts: 5,373
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sparky Offline
Member
Quote
Sparky, you bring up a good point. I would imagine that since the GFCI detects unbalanced return current on the neutral, that any 24 volt secondary anomaly would not be reliably interrupted. A voltage to human contact would probably just look like a bigger load to the primary side, and would not necessarily trip the GFCI.


well, we do it for pools in 680 ptfw, one would think such xformers would have some sort of an amperage limit, but maybe i'm missing some key theory here?

Quote
I do have lighting and switches in or near a wet area, and that is mostly why I have the GFCI.


I wire baths with 210.11-C-3- exception in mind because people will always be approaching us with some stretch of the 'other equipment' line in it, like you're dealing with

Usually the manufacturers instruction dictate something in the order of "ok in a tub/shower zone if GFI protected"

I don't know how they come about it for xformers


oh and , minding my manners, welcome aboard ptfw

~S~


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