Why Would Previous Owner(s) Do This???

Reply

  #1  
Old 04-03-13, 12:03 PM
Member
Thread Starter
Join Date: Apr 2013
Posts: 3
Why Would Previous Owner(s) Do This???

Updating a thermostat that controls 4 small baseboard heaters, I went to basement and turned off the breaker which is two 120v(20A) single poles connected together with a metal bar (not sure technical term). When I do so, the 4 outlets in my finished basement next to the panel go off. I know because the defumidifier turns off. I then test with a multimeter the thermostat, its hot with about 60v. One by one I turn off other breakers and when the "Garage" 120v(20A) is turned off the thermostat finaly is dead (plus the garage). Makes no sense. For reference, all outlets are 120V(15A), wire is 12 gauge. Now I only found this because of the updating, everything was running fine before, but my concern is could there be a safety problem lurking.

I am sure this is by far not code, but could it have been done safely? What problems could this cause (i.e. wires overheating, breaker wont trip)?
 
Sponsored Links
  #2  
Old 04-03-13, 12:09 PM
Member
Join Date: Oct 2010
Location: USA
Posts: 563
My guess is that the danger is that one side trips prematurely because of the other devices drawing power.
 
  #3  
Old 04-03-13, 12:37 PM
Member
Join Date: Mar 2013
Location: USA
Posts: 41
I'd start checking for a bad ground. The 60V kind of makes me wonder. I'm not one to talk though since I have seen many previous owner improvements (disasters) in the home I purchased towards the end of October.
 
  #4  
Old 04-03-13, 12:51 PM
Nashkat1's Avatar
Member
Join Date: Mar 2012
Location: USA
Posts: 8,470
Updating a thermostat that controls 4 small baseboard heaters, I went to basement and turned off the breaker which is two 120v(20A) single poles connected together with a metal bar (not sure technical term).
The term is a "handle tie." The 240V circuit for your baseboard heaters should be supplied by a 240V 20A two-pole breaker.

The difference is that a handle tie provides common disconnect without common trip. A 2-pole 240V breaker provides both. Two single-pole breakers with their handles joined with a handle tie is the appropriate protection for a multiwire branch circuit.

Can you move the handle on one of the "two breakers" without moving the other?

----------------

It's really easy to get wires mixed up in a panel. You need to tone out the wires to the different loads and terminate each to the proper breaker(s). Yes, it could be dangerous the way it is now.

The grounding conductors should have no bearing on this.
 
  #5  
Old 04-03-13, 12:55 PM
Nashkat1's Avatar
Member
Join Date: Mar 2012
Location: USA
Posts: 8,470
I'd start checking for a bad ground.
Why? How would the grounding conductors come into this. Did you mean a bad or loose neutral?

There's no neutral in a straight 240V circuit, so I'm not sure how that enters into it either.
 

Last edited by Nashkat1; 04-03-13 at 02:10 PM.
  #6  
Old 04-03-13, 01:10 PM
Member
Thread Starter
Join Date: Apr 2013
Posts: 3
Both handles move together.
 
  #7  
Old 04-03-13, 01:14 PM
Member
Thread Starter
Join Date: Apr 2013
Posts: 3
It's really easy to get wires mixed up in a panel. You need to tone out the wires to the different loads and terminate each to the proper breaker(s). Yes, it could be dangerous the way it is now.
Do you think that this could have been just simply by mistake and sourced/corrected at the panel?
 
  #8  
Old 04-03-13, 02:12 PM
Nashkat1's Avatar
Member
Join Date: Mar 2012
Location: USA
Posts: 8,470
Both handles move together.
Then that's a 240V 2-pole breaker. It's correct.

Do you think that this could have been just simply by mistake and sourced/corrected at the panel?
Yes.
 
  #9  
Old 04-03-13, 05:08 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,221
To be absolutely safe, I think I'd replace the 20 amp 2 pole breaker.
 
  #10  
Old 04-03-13, 07:05 PM
Nashkat1's Avatar
Member
Join Date: Mar 2012
Location: USA
Posts: 8,470
To be absolutely safe, I think I'd replace the 20 amp 2 pole breaker.
I'm curious - why would you do that?
 
  #11  
Old 04-04-13, 01:28 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: NJ - USA
Posts: 43,494
Everyone is assuming the heaters are 240 volts. The OP says when he turns off the two breakers, or the 2 pole breaker, that the small heaters and the receptacles go dead.

That's a problem in itself. It should first be confirmed that the heaters are indeed 240 volts.

That could be a split circuit with the wrong breaker.
 
  #12  
Old 04-04-13, 05:21 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,221
To be absolutely safe, I think I'd replace the 20 amp 2 pole breaker.
I'm curious - why would you do that?
I've seen too many old circuit breakers with damage to the internal contacts that would not fully open when the breaker was turned off. It's only $8, replacing an old breaker is never a bad thing in my book.
 
  #13  
Old 04-04-13, 09:10 PM
Nashkat1's Avatar
Member
Join Date: Mar 2012
Location: USA
Posts: 8,470
I've seen too many old circuit breakers with damage to the internal contacts that would not fully open when the breaker was turned off. It's only $8, replacing an old breaker is never a bad thing in my book.
Ah, got it. That's why I test them if they don't seem to be as good as new.
 
  #14  
Old 04-05-13, 04:55 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,221
Do you test for continuity or millivolt drop across the internal contacts?
 
  #15  
Old 04-05-13, 05:22 PM
Nashkat1's Avatar
Member
Join Date: Mar 2012
Location: USA
Posts: 8,470
I test for good, clean snap action to all positions and for continuity. Testing for millivolt drop is an interesting thought, though.
 
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
Display Modes
'