Hi,
I have just installed a 12 KW instant water heater. The heater calls for awg 6 and a 60 amp double pole 240 vac breaker. I pulled two Awg 6 wires and an Awg #8 for the ground. I removed the old 50 amp breaker and installed a new 60 Amp Commander breaker.Everything seemed to be doing Ok until I smelled a strange smell and heard a little 'tickling sound coming from the breaker panel. When I removed the panel cover I saw an intermittent arcing between one of the two 'screwed in' terminal straps on the breaker and the bar. I presumed that the wire may need tightening and torqued it down some more.
When I turned the power back on and operated the shower all appeared well but I left the panel cover off. Later the same evening (hence dark) while a friend was using the shower I again smelled burning....I checked the panel again and saw that the same terminal strap was glowing orange. The breaker DID NOT TRIP and Iswitched it off manually.
Questions
1 Could the breaker be faulty?
2 could it be caused by chafing in the conduit?
3 could it be caused by a loose connection in the heater itself?
4 Why did the breaker NOT TRIP?????
Any answers or suggestions to the above or in general would be gratefully received.
You have a loose connection either in the breaker or where the breaker bolts into the panel. This much you know.
It is easy to get a screw cross threaded when installing a bolt in breaker. Another posibility is that the breaker could be a factory defect. I have never heard of the commander breaker till today so I do not know about thier relyability.
The problem now is that the buss bar and tab on the breaker have gotten so hot that you cannot be sure that the metal is still any good.
If the buss bar is not dammaged too bad, you could try to install a new breaker in different slots. I would use an amprobe, after this is done, to see what the actual amp draw is on the circuit.
I also would never leave a panel cover off un-attended. If something in there were to start burning, the fire could be allowed to spread before the main breaker had a chance to trip.
Hi Mr White,
Thank you for your response. All your points are gratefully noted. I am not at that location right now but I will buy a new breaker when the stores open tomorrow. Unfortunately the panel is full..... is there a proprietry tool for 're-threading' buss bars?
I am intrigued why the breaker did not trip...one would assume (although assumption isnt encouraged) that that is one of the purposes of its existance.
Hi Mr White,
Thank you for your response. All your points are gratefully noted. I am not at that location right now but I will buy a new breaker when the stores open tomorrow. Unfortunately the panel is full..... is there a proprietry tool for 're-threading' buss bars?
I am intrigued why the breaker did not trip...one would assume (although assumption isnt encouraged) that that is one of the purposes of its existance.
In addition to what christopher said, the answer to your last question is no. buss bars may not be re-thread. In fact the entire bar could be dammaged to some degree. Once the metal has been heated once, it takes less heat to cause the problem again. This is a snow ball effect. Replacement is the best option. If you have no other open spots, then you may need to replace the panel guts.
In addition to everything jwhite said which stands as written,
1 Could the breaker be faulty?
Now likely, when installed not likely, if so it had defective busbar clamps.
2 could it be caused by chafing in the conduit?
No.
3 could it be caused by a loose connection in the heater itself?
No.
4 Why did the breaker NOT TRIP?????
The breaker did not trip because there was no load-side fault. The breaker is thermal magnetic. This means that a load-side overload will overheat the breaker and trip in minutes. A load-side short-circuit will magnetically trip the breaker instantaneously. Eventually, line-side heat in the panel will trip the breaker and do so safely only if the cover is on the panel!
I checked the panel again and saw that the same terminal strap was glowing orange
you are welcome and I am sorry we had to bare bad news.
this is a good example of why it is sometimes better to hire a professional electricain. while it is true that he may have had the same problem. he would now be responsible for fixing it.
I'd get an electrician out at this point to see if the panel has been damaged, rather than just plug another breaker in an risk a fire. Never heard of a Commander breaker either, may be a regionally distributed product. As for the not tripping breaker, Christopher has the technical aspect covered, but from personal observation, I have seen wires completely melt through and not trip the breaker until they created a direct short. Also different brands of breakers have different tolerance levels before they trip. I find Square D to be one of the quickest responders.
Hate to tell you this and its obviously not meant as damning statement against all electricians but some of the things I have seen done recently by people who want to charge me for the opportunity to witness their dangerous incompetence...make me rather be responsible for my OWN incompetence...with a little help from my friends
Thanks
You can always just collect the money from the insurance co after explaining that you didn't trust an licensed electrician to do it so you did it yourself. Should be easy to get insurance after you do that.
I didnt expect you guys to be so touchy. I can only speak from experience and they were not the cheapest in the book. I admire your solidarity but I am a tradesman (not a handyman) too and I believe that shoddy workmanship should not be defended...however we are ALL entitled to our points of view.
Insurance only doesn't pay if it is prooved to be arson. If they didn't pay off on stupidity then they would never have to pay. Think about people who leave candles burning, fall asleep smoking, leave pot on stove.
Not Touchy at all just seen nothing in your thread that pointed to an electrician being consulted nor that an electrician did a shoddy job. I have no problem with HO's being DIY's. I myself am that way. I just happen to be an electrician that repairs about 100 or so diy's electric jobs a year and have seen things that would baffle your imagination. 9/10 times it would have been cheaper to have me do it in the first place.
I have also been on the Volunteer Fire Department for over 15 years. I am sure you can gather the rest.
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
DIY Home Improvement Forum
3.1M posts
319.6K members
Since 2003
A forum community dedicated to Do it yourself-ers and home improvement enthusiasts. Come join the discussion about tools, projects, builds, styles, scales, reviews, accessories, classifieds, and more! Helping You to Do It Yourself!