Carrier Fan Coil 5K Heater Circuit Breaker Size

[ATC USN]

My Carrier FE4ANB005 Fan Coil has 10K and a 5K heater pack, the 10K is fed by a 60 amp circuit the 5K is fed by a 30 amp circuit, but the fan coil has two 10K (60 amp) breakers.

The reason I’m asking is the 30 amp breaker on my load center that feeds the fan coil/5k Heater has tripped about 10 times this winter.

I replaced the 30 amp breaker Saturday, today the installer ran an electric heat test and inspected the wiring, he said he didn’t find any problems, but he also didn’t take any current readings.

This system is less than one year old.

[BaldLoonie]

The breakers on the heat kit are more of a service disconnect and dead short protection. Your 60 & 30 in the main panel are right. Maybe a bad breaker.

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[ATC USN]

I guess the installer was out of 30 amp breakers, when they installed they system they borrowed a can of spray foam and a role of aluminum tape from another contractor who was residing my house.

[beenthere]

The breakers in the unit come from the factory.

[ATC USN]

Looking at the product data sheet two 60 amp breakers is correct.
If I'm reading the product guide correctly FE4ANB005 Fan Coil with a 5K heater pack calls for 8 gauge wire and a 35 amp breaker, mine is wired with 10 gauge wire with a 30 amp breaker.
A 5KW heater should be pulling about 20 amps, that leaves 10 amps for the blower motor and electronics.

[jtrammel]

Sounds like a week breaker to me, which should be resolved now that its been changed. Has it tripped since changing the breaker?

[ATC USN]

No not since the breaker was replaced, the last time it tripped the temp was in the low 20's.
The old breaker tripped intermittently about 10 times since the winter season started.
I have an infinity tstat running the electric heat test did not trip the old breaker.

[ATC USN]

It's not the breaker the new breaker just tripped.
I was able to duplicate the problem by running the heat test for 10 minutes instead of the default 5.
The wires and breakers are warm and the technician who was out earlier didn't check the current draw.

[ATC USN]

Am I wrong?

[toocoolforschool]

Sounds like you have a short or some loose wires or maybe a incorrectly wired heat strip. Pictures would help.

[ATC USN]

Sounds like you have a short or some loose wires or maybe a incorrectly wired heat strip. Pictures would help.

Nope I checked the wiring and a technician checked it again on Monday.
Did you look at the product data sheet? The minimum ampacity is 33.5 amps, including blower motor.

[ATC USN]

I was wrong the wring and the circuit breakers are correct the technician told me I had a 5k and a 10k heater pack I don’t, I actually have a 15k heater pack. The dealer is replacing it tomorrow.

[vstech]

a 15K heater pack is actually 3 - 5 K heat strips... it's all in how it's wired.
the problem is HEAT on the conductor... 5K with 240v can pull over 22 amps, and undersized wire, with crimp connectors, with sequencers and other points of resistance and you can easily overtemp a 30 amp breaker.
if you have #10 wire, and a 30 amp breaker, you will need to upgrade the wiring to the furnace, to increase the breaker size.

if the breaker trips more than ONE TIME there is a problem that must be addressed.
if the first technician cannot find a problem, do not pay him, and get a technician that CAN find the problem.