ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
Do we need grounding?
by gfretwell - 04/06/24 08:32 PM
UL 508A SPACING
by tortuga - 03/30/24 07:39 PM
Increasing demand factors in residential
by tortuga - 03/28/24 05:57 PM
Portable generator question
by Steve Miller - 03/19/24 08:50 PM
240V only in a home and NEC?
by dsk - 03/19/24 06:33 AM
New in the Gallery:
This is a new one
This is a new one
by timmp, September 24
Few pics I found
Few pics I found
by timmp, August 15
Who's Online Now
0 members (), 96 guests, and 10 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
#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...

Stay up to Code with the Latest NEC:


>> 2023 NEC & Related Reference & Exam Prep
2023 NEC & Related Reference & Study Guides

Pass Your Exam the FIRST TIME with the Latest NEC & Exam Prep

>> 2020 NEC & Related Reference & Study Guides
 

Joined: Jan 2005
Posts: 5,445
Likes: 3
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.

Joined: Jun 2011
Posts: 3
P
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.
Joined: Apr 2002
Posts: 7,381
Likes: 7
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
Joined: Oct 2000
Posts: 5,392
S
Member
just an aside here, what can be expected of a line side gfi meant to protect xfomer secondaries?

~S~

Joined: Jun 2011
Posts: 3
P
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.
Joined: Oct 2000
Posts: 5,392
S
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~


Link Copied to Clipboard
Powered by UBB.threads™ PHP Forum Software 7.7.5