ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
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
Do we need grounding?
by NORCAL - 03/19/24 05:11 PM
240V only in a home and NEC?
by dsk - 03/19/24 06:33 AM
Cordless Tools: The Obvious Question
by renosteinke - 03/14/24 08:05 PM
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 (), 260 guests, and 19 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Joined: Mar 2005
Posts: 16
J
JoeMed Offline OP
Member
Typical doorbell transformer in the panel. I rarely see this but can any one direct me to why or why not, in the NEC 2002, for this type of installation.
Thanks Joe

Joined: Jul 2004
Posts: 9,923
Likes: 32
G
Member
Do you mean mounted in a 1/2" KO in the panel? (only the line voltage leads inside) Otherwise how are you separating the class 2 wiring from the line voltage?


Greg Fretwell
Joined: Mar 2005
Posts: 16
J
JoeMed Offline OP
Member
thanks for responding, No mounted inside the panel. no separation, all romex install, the low-v wires go out in an opening in the panel, panel is an exterior installation

[This message has been edited by JoeMed (edited 06-02-2005).]

Joined: Jul 2004
Posts: 9,923
Likes: 32
G
Member
725.55 ?


Greg Fretwell
Joined: Mar 2005
Posts: 16
J
JoeMed Offline OP
Member
I'm ckecking it out and re-re reviewind article 450

Joined: Jul 2004
Posts: 9,923
Likes: 32
G
Member
"JoeMed I'm ckecking it out and re-re reviewind article 450"

Look at 450.1 ex2

450.1 Scope.
This article covers the installation of all transformers.

Exception No. 3: Transformers used with Class 2 and Class 3 circuits that comply with Article 725.


Greg Fretwell
Joined: Mar 2005
Posts: 16
J
JoeMed Offline OP
Member
I need clarification on Class 1,2 and 3. Under 725 class 1 not more than 30v.
Can you advise? 725.21 (A)

Joined: Jul 2004
Posts: 9,923
Likes: 32
G
Member
The short answer is
Class 1, not current limited, treated virtually the same as "power"
Class 2, low voltage, current limited, like your doorbell.
Class 3, higher voltage, still current limited, like a phone line.


Greg Fretwell

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