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  #11   IP: 66.59.114.225
Old January 20th, 2006, 05:17 PM
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mdshunk mdshunk is offline
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To make sure I understand what you have so far:

-5 electric baseboard heaters
-each with their own thermostat
-powered on the same circuit
-by a double pole 30 amp breaker
-baseboard heaters quit working from time to time
-breaker never visually shows as tripped
-when you toggle the breaker 'off' then 'on', the heaters work for a short spell

Do I have this right? If so, here's what I'm thinking:

The only thing all your heaters have in common is this breaker, and the cable coming from the breaker to the first thermostat in the chain. I'm suspecting the breaker at this point. More specifically, its connection onto the buss rail of the panel. This Murry style breaker you've pictured is somewhat famous for developing a bad connection to the buss rail. This will effectively cut off one leg of the power. My thinking is that turning the breaker off then on "rocks" the breaker just enough to re-establish the connection on the buss rail to let it work briefly. My next troubleshooting step would be to unclip the breaker from out of the panel and examine both the buss rail under the breaker and the mating portion on the breaker for burnt spots. If this is what you find, replace the breaker with a new one, abandon this spot in the panel, and clip the new breaker in a new spot.
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  #12   IP: 69.254.246.210
Old January 20th, 2006, 05:24 PM
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Roger Roger is offline
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Sorry I've been trying to post but am experiencing problems on my end or with the site.

Well you have a t-stat for every heater so that most likely rules out a thermostat problem. Since you are losing all the heaters it almost sounds like that breaker is tripping. It is a little puzzling to me if it isnt tripped why the heaters will all come back working everytime you reset it. Can you tell if it isnt really tripped? Sometimes they arent real easy to determine if they tripped out.
If you want take one of the covers off a theromstat and expose the wires with the power turned off of course.
Then turn the power back on. There should be two wires coming into the t-stat. Make sure the t-stat is on max setting. Take your meter set up the way I said and carefully touch the red probe to one screw terminal that one of the wires is connected then touch the black probe to the ground wire (probably bare). You should read 120 volts. Do the same thing to the other wire connected to the t-stat it should also read 120 volts. When the heaters stop working retest and see if you still have 120 volts. If not then you have lost power to the circuit or at least to the one leg. If you do this test make sure you can touch the wires coming to the t-stat with the probes without coming in contact with them. If there are more than two wires coming into the t-stat let us know. Post back with the results.

Edit: Again sorry. I saw your reply an hour ago and it now appears that it may have been a problem on my end...No it wasnt operator error..

Last edited by Roger : January 20th, 2006 at 05:28 PM.
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  #13   IP: 64.180.241.198
Old January 20th, 2006, 11:00 PM
Bernz Bernz is offline
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Quote:
Originally Posted by mdshunk
To make sure I understand what you have so far:

-5 electric baseboard heaters
-each with their own thermostat
-powered on the same circuit
-by a double pole 30 amp breaker
-baseboard heaters quit working from time to time
-breaker never visually shows as tripped
-when you toggle the breaker 'off' then 'on', the heaters work for a short spell

Do I have this right?
Yes.
Quote:
Originally Posted by mdshunk
My thinking is that turning the breaker off then on "rocks" the breaker just enough to re-establish the connection on the buss rail to let it work briefly.
I wanted to test this theory, so I pushed the breaker (without touching the switch) to "rock" it and see if the connection would re-establish and lo and behold it worked! I then set all 5 t-stats to a high temp for about 5 minutes. They all worked as they should.
Quote:
Originally Posted by Roger
If you want take one of the covers off a theromstat and .... Post back with the results.
Roger, should I still do this test having mentioned the above?

Marc, I found this site. The instructions start just above the halfway point of the page...at 'step one'. Would you recommend this webpage as a good guide for replacing breakers?

Thanks again for all of the replies! --Bernz

Last edited by Bernz : January 20th, 2006 at 11:26 PM.
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  #14   IP: 69.254.246.210
Old January 21st, 2006, 08:57 AM
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No it isnt necessary to do the test. It looks like Marc figured out what the problem was.
The test would be good practice understanding how to use your multimeter but I would wait till spring....

If they are working I wouldnt press my luck.

Good luck
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  #15   IP: 64.180.241.198
Old January 22nd, 2006, 11:58 PM
Bernz Bernz is offline
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So I decided to open the panel up to have a look-see. Without having to remove the breaker it was fairly evident that something nasty is going on.

In order for you to have a decent look at this, I posted a photo of the front of the panel for reference, an overall photo of the inside of the panel and a closeup shot of the problem area.

I've since shut off 9 / 11 - I'm starting not to like these two numbers together.

Let me know your thoughts...I appreciate you taking the time to provide any input you can.

- Bernz

As a side note, the townhouse I live in is part of a 30 unit townhouse complex which seems to have issues with lightbulbs burning out prematurely. I don't know if this relates but I'm now wondering if this is something I should bring up with our strata council members to look into.
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  #16   IP: 69.254.246.210
Old January 23rd, 2006, 01:15 AM
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Hi, Bernz. My gosh that panel really has had some serious arcing and overheating going on.

I think Mdshunk will have plenty to point out to you about this panel.

My observations aside from the obvious damaged busses are...

It appears to me to be #12 awg copper connected to the 30 amp double pole breaker protecting the baseboard heater branch circuit. You would need to verify that for us. This would be too small of wire, in fact those heaters are continuous loads and really should be sized at 125% for ampacity purposes. So that would make the wire size #8 awg copper.....1.25 x 31.25 = 40 amp breaker not a 30. So even if they are #10 they arent sized correctly in my opinion. I believe that would be very unusual to have that much load on a heater circuit like yours. So someone knowledgeable needs to take a close look at how that heater circuit is designed. I've never seen one like what you have there but havent worked on but a handful of baseboard heaters.
I dont think it has been pulling maximum amperage though because the wire where it connects to the breaker doesnt show any overheat damage. So I would say you have one crappy loose connection between that breaker and the busses.

Second thing I see is it appears that there are numerous neutrals under one screw on the neutral bar. That one screw on the right looks like it has 5 or 6
neutrals under it. That is a violation in the USA. Not sure about Canada.

Next thing I see is it appears that the grounding bar is not utilized but instead someone sheetmetal screwed several little 3 hole accessory ground bars all over the place in the panel and then landed several grounds under each screw of those ground bars. So I'm guessing the bonding to the neutral bar is with a bonding screw somewhere.

At first I thought this was wired as a sub-panel but now I dont think so as I look closer. I'm more inclined to think it is just the main panel with the main disconnects for the townhomes grouped outside with a meter bank.

I'm just not familair with this Murray panel. Marc can probably fill us in.

It appears to be a convertible mains panel cause I believe those two unoccupied studs above the main lugs is where the main breaker kit would mount.

Well all of that is irrelevant because you need to bring that overheated panel to the attention of the city codes enforment department (local building code people). My guess is they are going to have a look see at all the panels of all those townhomes.

For what its worth that panel is going to have to be replaced and the sooner the safer.

Roger

Last edited by Roger : January 23rd, 2006 at 06:11 AM.
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  #17   IP: 24.16.225.236
Old January 23rd, 2006, 08:29 AM
suemarkp suemarkp is offline
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I'm also curious about the multiwire branch circuits on the twin breakers. I can't tell if the red and black go to different phases or not (wires get lost in a jungle of colored wires). After seeing how this panel was done, I think I'd check out each multiwire branch circuit to make sure they are wired correctly and you're not overheating the neutral.

I think I'd also try to find a way to break up the heater circuit so that its two 20A circuits instead of one 40A one. I don't know if the heaters or thermostats are listed to be on a circuit larger than 20 amps.
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  #18   IP: 66.59.114.116
Old January 23rd, 2006, 02:21 PM
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There is no repair option for what you have there other than replacing the panel. Sorry to say, but you really need to put this in either your budget or your schedule. It is a pretty neat wiring job, overall. It was just done with inferior material. Sorry to say, but the majority of your breakers will also not be reusable. I'd suggest replacing it with a better brand and style such as Cutler-Hammer CH series, or Square 'D' QO series. Anything but that Murry you have there now.
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  #19   IP: 70.68.241.136
Old January 23rd, 2006, 05:20 PM
Bernz Bernz is offline
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Thanks Roger, Mark and Mdshunk.

Mdshunk - the panel has "Commander" on the cover...I don't see "Murry" anywhere. "Commander" is also the name brand of the breakers, is this brand not recommended? I'm wondering what is the root cause of the panel overheating is... inferior material? Or is it possible the load from the disconnect is contributing to this?

There is a council meeting tonight so I'd like to bring as must expert knowleage as I can incase this issue is bigger than meets the eye.

Again, thanks for your time!

--Bernz
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  #20   IP: 66.59.114.29
Old January 23rd, 2006, 05:56 PM
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Quote:
Originally Posted by Bernz
Mdshunk - the panel has "Commander" on the cover...I don't see "Murry" anywhere. "Commander" is also the name brand of the breakers, is this brand not recommended?
Are you in Canada?? I only know that as an old Canadian brand, now owned by Cutler Hammer. I'm pretty sure they squashed that line at the same time as they squashed Challenger (the US version of Commander). Must have been a reason. I should have noticed right away that they were bolt on breakers from your close up shots. They look like Murry's from the far shots, but I see now that they are the QBH Commander type. This panel must be pretty friggin old, then.

Quote:
Originally Posted by Bernz
I'm wondering what is the root cause of the panel overheating is... inferior material?
Uh, yup. That would be my opinion. Either that, or the buss screws were never tight to begin with.

Quote:
Originally Posted by Bernz
Or is it possible the load from the disconnect is contributing to this?
No, the disconnect ahead of this panel puts no "load" on the panel. It just serves as the main overcurrent protection for the panel.
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