Hvac heat strips blowing breaker

[Ron Citerone]

So I open up the cottage today after being closed since November. I have a central air conditioner with heat strips in it for spring and fall. Turn on heat and all is well. Then the 60 amp breaker trips. Never did it before since new, 15 years. The filter is brand spankin new. Even ran it without filter. After 10 minutes or so breaker blows. Several times. Before I call the man, should I switch out the breaker with a new one? That’s all I can do easily. Thermostat is 4 years old and seems to be working flawlessly. Any thoughts on breaker getting weak? Thanks, Ron

[Maurice Mcmurry]

I would check the lugs where the wires connect to the circuit breaker. They should be very tight.
Take precautions to avoid getting shocked or causing a short.

[Bill Howatt]

I agree with Maurice as a first thing to check. It sounds like something is causing extra breaker heating rather than a short circuit.
Do you have a clip-on ammeter so you can check the current draw? If you get a rise in current before the breaker trips then something in the unit is failing. If it trips with the current below say 80% of the breakers rating then something is heating the breaker like a poor connection at the lugs or the breaker has become weak.

[Bill Dufour]

Check main connections at the heat strips as well. They are more likely to overheat at that end. Got a laser thermometer? Run the heat for a few minutes and laser all the connections. If not turn off power and feel each connection for over heating.
BilL D

[Michael Schuch]

Breakers do go bad. When my parents moved into their house about 30 years ago they were constantly tripping breakers. We replaced EVERY breaker in the panel and they haven't had any problems since.

I would swap out the breaker. It will be a TINY FRACTION of the cost of calling an electrician. If that doesn't solve the problem then I would put a clip around ammeter on each leg (separately) and see what the current draw is when the heat is running. I think a new breaker is quite likely to fix the problem.

[George Yetka]

Agree with Michael. If possible replace the breaker it will be less than $20 in most cases. The next would be, If possible, turn off all heaters and energize them one at a time. Once it trips turn the last one back off and turn on the rest. If this works OK try turning only the culprit on. It may be a bad strip. This is less likely than a bad breaker but possible

[Ron Citerone]

Ok, update. I don’t have a clip on ammeter or thermal laser. I looked at breaker this morning. No visual problems. I tightened the connections, but honestly, they seemed tight. Presently I am running the heat with thermometer set high and window open. After an hour no tripping. The breaker is warm to the touch, but not hot. I think when I come back in a week or so I will bring a new breaker and switch it out. If it recurs I will get pro help. I appreciate all your advice. Any other thoughts welcome. Thanks, Ron

[Bill Howatt]

I think your plan is a good one.
When you have the old one out, check the connections to the buss bars underneath (assuming the usual plug-in type) to make sure they aren't seriously oxidized or show signs of overheating. If so, move the breaker to a different location if possible.
The breaker getting a little warm is not unusual but never hot. If a breaker gets to 140F it should have tripped.

[Maurice Mcmurry]

I have had cases where it only took an eighth of a turn on the lugs to correct a finicky breaker. Also check for aluminum wire which can create this problem. When I find aluminum wire I make sure everything is rated Cu-Al and has been treated with Ox-Gaurd.

[Bill Dufour]

Any chance this is a Zinsco or Federal Pacific panel?
Bill D

[Ron Citerone]

Not sure. I saw Square D breakers in it so I assumed Square D. I am not there right now but will look closer when I get back down there.

[Bill Howatt]

If it has Square D breakers it is a Square D panel. The will not fit in Zinsco or Federal Pacific panel.

[Bill George]

If it has Square D breakers it is a Square D panel. The will not fit in Zinsco or Federal Pacific panel.

But there are two types of Square D, standard ones like I normally see and Homeline and I do not know if they are interchangeable?

[Ron Citerone]

But there are two types of Square D, standard ones like I normally see and Homeline and I do not know if they are interchangeable?

They are not interchangeable. I just saw a video from the manufacturer. Thanks for pointing that out.
I will get the one that fits my box.

[George Yetka]

Its been a while but 2 pole breakers for either QO or HOM should be under $30 I would grab both if you are not sure and when you get to the panel use the one that matches and return the other

[Ron Citerone]

But there are two types of Square D, standard ones like I normally see and Homeline and I do not know if they are interchangeable?


Its been a while but 2 pole breakers for either QO or HOM should be under $30 I would grab both if you are not sure and when you get to the panel use the one that matches and return the other

Good idea George. Especially since the cottage is 35 minutes from the nearest store. Will do.

Thanks everybody for your help, much appreciated!

[Bruce Wrenn]

Hoimeline and QC breakers aren't interchangable. Two pole breakers now cost around forty bucks.

[Ron Citerone]

Well I got back to the cottage today. I replaced the breaker with a new one. Ran the heater for over an hour and breaker did not trip. Also, while it did get slightly warm, it was nowhere near as warm as the old breaker was getting. Fingers crossed that the problem is solved. Will be here through tomorrow so fingers crossed. Thanks again folks!