Breaker Question

[Mathew Hawley]

The air handler unit at todays inspection is a Lennox unit with a 7.5 KW heat strips. The unit was drawing 35.2 amps and was on a 100 amp breaker.

The homeowner said he would replace the breaker and wanted to know what size breaker to install.

My question is what size breaker should it be on and am I correct by writing it up as being on an oversized breaker and succeptible to damage. I tried calling the manufacturer and was on hold forever.

Thanks in advance

[Blaine Wiley]

What size breaker did the data plate call for? That is the correct size to install.

You are correct to write it up if the breaker is not sized per the manufacturers instructions.

[David P. Valley]

Originally Posted by mhawley

The air handler unit at todays inspection is a Lennox unit with a 7.5 KW heat strips. The unit was drawing 35.2 amps and was on a 100 amp breaker.

The homeowner said he would replace the breaker and wanted to know what size breaker to install.

My question is what size breaker should it be on and am I correct by writing it up as being on an oversized breaker and succeptible to damage. I tried calling the manufacturer and was on hold forever.

Thanks in advance

The recommended breaker size should be noted on the manufacturers data tag inside the casing somewhere.

[Mathew Hawley]

David & Blaine

Thank you very much for your reply. I did not get the info off of the data plate. I usually take photos of the data plates. I only took a pic of the condensing unit data plate I forgot the AHU data plate.

I will advise the homeowner to look at the plate or make a trip back out to the home.

Thanks again for your reply

[Mathew Hawley]

Shooting from the hip, I would think a 40 amp would do. Ahh, I better go back out there.

[Blaine Wiley]

Originally Posted by mhawley

Shooting from the hip, I would think a 40 amp would do. Ahh, I better go back out there.

Good idea. The data plate on my Lennox A/H with 10kw calls for a minimum 50 and a maximum 60 amp breaker.

It is also advisable to make a standard practice of checking that the circuit breaker in the service panel, or at the equipment disconnect is rated within the manufacturers specs.