2-wire vs. 3-wire

Reply

  #1  
Old 05-16-05, 10:49 AM
pmazzola57
Visiting Guest
Posts: n/a
2-wire vs. 3-wire

I live in a home that was built in 2001. I just purchased a Smarthome switch that has three wires plus a ground wire. When I opened the switch box, the switch there only had two wires plus a ground.

Based on posts I've seen on other forums, two wire is old technology and I am little concerned that my house was not built to code.

In any event can I get a primer on what the three wires are for, and is there a way to make the 3-wire switch work on my 2-wire system?
 
Sponsored Links
  #2  
Old 05-16-05, 12:41 PM
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,973
Received 0 Votes on 0 Posts
Two wires plus a ground is for a switch loop. It is not "old technology". There is nothing wrong with it, and sometimes it is the best way to run a circuit. Whatever you read on this other web site is incorrect.

The main disadvantage of a switch loop is that there is no neutral wire present. This means you canít tap the switch for an additional receptacle or light from the switch.

Refer to the documentation for this smart switch. Determine what the three wires are for. If one is for a neutral then you cannot use this switch. If, however, the switch is designed for three way operation then you can use it. The directions with the switch will tell you exactly how to connect it.
 
  #3  
Old 05-16-05, 12:49 PM
Member
Join Date: Sep 2004
Posts: 83
Received 0 Votes on 0 Posts
Did you purchase the Smarthome 2 way dimmer? A neutral is required which appears not to be present in your case.

Were you looking for X-10 capability or just replacing a single pole switch with a dimmer?
 
  #4  
Old 05-16-05, 02:43 PM
Member
Join Date: Dec 2000
Posts: 510
Received 0 Votes on 0 Posts
For a switch loop (no neutral) you need to get something like this:

http://www.smarthome.com/2384w2.html
 
  #5  
Old 05-16-05, 03:37 PM
Speedy Petey's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Nov 2003
Posts: 2,455
Received 0 Votes on 0 Posts
Originally Posted by pmazzola57
Based on posts I've seen on other forums, two wire is old technology and I am little concerned that my house was not built to code.
It's amazing how much wrong and misleading information is out there on the web.
 
  #6  
Old 05-17-05, 02:15 AM
Skapare's Avatar
Member
Join Date: Jun 2004
Location: USA
Posts: 198
Received 0 Votes on 0 Posts
Some people may be counting the grounding wire when they say 2-wire is old technology. They would say it is 3-wire if there is a grounding wire present.

When referring to the wires, don't count the grounding wire in the number. That wire is required virtually everywhere, so it should just be there no matter what. If you want to make it even clearer to others, you could say "2-wire plus ground" instead of just "2-wire". Cable nomenclature will refer to this as "14/2" or "12/2" (it does not count the grounding wire, though older cables might indicate ground with an added "G" or "+").
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: