issue with breaker trip

[e-z breez]

I'm in a situation right now were the breaker will trip after about 15 min in heat mode I'm dealing with a aruf364216ca airhandler first i thought the breaker could be the problem cause it had a 50 amp double pole and the heat kit is 10kw so i changed it to a 60 amp worked fine before i left waited about 35 min a week later customer called same issue i directly went to change heat kit but the same issue scratching my head on this one one any suggestion?

[hvac69]

What is the actual operating amperage of the heating elements?
What is the wire size from the breaker to heater?

[Rusty49]

Is the air handler and heat strip the only thing on the breaker? I've come across some that had the outside unit connected to the same breaker as the airhandler.

[iszell]

Is this new/old install???

[Paul Bee]

If you have an amp clamp meter with min-max you can hook up your meter and see if the circuit is exceeding the rating of the breaker. Burned or corroded busbars can cause excessive heat at your circuit breaker. In my state this is a job for an electrician. Are you a service tech? your profile doesn't say.

[e-z breez]

when i go to do the amp draw it reads 47.5
the wire used is an #8 and the unit is on its own breaker nothing else
it looks like a fairly new install Yes I'm a service tech Should i be looking at the blower motor?

[Rusty49]

60 AMP Breaker and 8/3 Copper is what I use for a a10K strip. Does the Breaker get warm or emit any sound when strip is entergized? Doubt if the blower motor is tripping the the 60 amp breaker.

[e-z breez]

this why im scratching my head on this one cause it has the proper wiring 8/3 no it does not make any sound and as far as the breaker it might be a little warm really lite

[AC5096]

Did you try another circuit breaker? Maybe it's me, but with a 60A. circuit I use #6 copper.

[iszell]

What size breaker is in the electrical panel and what size breaker is at the air handler for the heater kit. Check the resistance at your heater kit, look for potential grounds.

[e-z breez]

when i first showed up for the call it had a 50amp breaker so knowing that the amp draw would be close to that i changed to a 60amp breaker and i would not go higher, normally what i would use for a 10-hkr heat kit is a 60amp the heat kit does not have a breaker on it, it has a block panel i have changed the heat kit once already same issue

[timebuilder]

when i go to do the amp draw it reads 47.5
the wire used is an #8 and the unit is on its own breaker nothing else
it looks like a fairly new install Yes I'm a service tech Should i be looking at the blower motor?

Sounds like not enough wire for the install.

Look at the equipment label. What is the minimum circuit ampacity?

If your continuous draw is 47 amps, you must size the conductor for 125% of that draw. Then, you must use 75C wire and have 75C terminations (at the unit AND the breaker) to use #6 wire. If you have 60C terminations, you have to go to #4.

I would keep the amp clamp there and look to see what is happening to draw enough current to trip the breaker. BTW, you don't just upsize a breaker unless it is according to the next size up rule when installing a branch circuit.

My bet is that this install was not inspected, and is not up to code. Once you have touched it, you "either knew or should have known" that an electrician was needed. Call one in tomorrow.

[timebuilder]

when i first showed up for the call it had a 50amp breaker so knowing that the amp draw would be close to that i changed to a 60amp breaker and i would not go higher, normally what i would use for a 10-hkr heat kit is a 60amp the heat kit does not have a breaker on it, it has a block panel i have changed the heat kit once already same issue

NO. You don't size it to be "close." This is a continuous load, and you must size the conductor for 125%, with a suitable breaker for THAT ampacity.

Get someone out there with an electrical license.