ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat Box
Recent Posts
From an outsider- How does tipping work?
by gfretwell - 01/23/21 06:13 PM
Photo Editing Software?
by JoeTestingEngr - 01/23/21 12:47 PM
Can I ask for your input?
by HotLine1 - 01/22/21 01:52 PM
T8 to LED retrofit-ballast or bypass?
by NORCAL - 01/22/21 11:01 AM
Ground fault remover :-)
by NORCAL - 01/16/21 10:29 AM
New in the Gallery:
Facebook follies, bad wiring
FPE in Germany pt.2
Who's Online Now
1 registered members (Scott35), 17 guests, and 15 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Low-V Trasnformer in the main service panel #52654 06/01/05 10:04 PM
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

Work Gear for Electricians and the Trades
Re: Low-V Trasnformer in the main service panel #52655 06/01/05 11:05 PM
Joined: Jul 2004
Posts: 9,557
G
gfretwell Offline
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
Re: Low-V Trasnformer in the main service panel #52656 06/01/05 11:23 PM
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).]

Re: Low-V Trasnformer in the main service panel #52657 06/01/05 11:43 PM
Joined: Jul 2004
Posts: 9,557
G
gfretwell Offline
Member
725.55 ?


Greg Fretwell
Re: Low-V Trasnformer in the main service panel #52658 06/01/05 11:54 PM
Joined: Mar 2005
Posts: 16
J
JoeMed Offline OP
Member
I'm ckecking it out and re-re reviewind article 450

Re: Low-V Trasnformer in the main service panel #52659 06/02/05 03:21 PM
Joined: Jul 2004
Posts: 9,557
G
gfretwell Offline
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
Re: Low-V Trasnformer in the main service panel #52660 06/02/05 10:04 PM
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)

Re: Low-V Trasnformer in the main service panel #52661 06/02/05 11:29 PM
Joined: Jul 2004
Posts: 9,557
G
gfretwell Offline
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

Featured:

2020 National Electrical Code
2020 National Electrical
Code (NEC)

* * * * * * *

2020 Master Electrician Exam Preparation Combos
2020 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
mersadrad
mersadrad
Montreal, Quebec, Canada
Posts: 28
Joined: March 2011
Show All Member Profiles 
Top Posters(30 Days)
Trumpy 15
NORCAL 12
Popular Topics(Views)
274,123 Are you busy
207,926 Re: Forum
195,574 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.3