Advice on a package A/C constantly tripping the breaker

[Denwad]

Hello gentleman I have a Coleman Suncutter with a addon electric heat package ( 59.7 amp draw ) and it constantly trips the 60 amp breaker its attached to.

I've opened it up and inspected the heating elements, no problem there, and i've checked the circuitry and wiring and nothing seems burnt.

its clearly drawing too much current but i haven't a clue why.

any clues where to look?

the model of the packaged a/c unit is 7430A601 and the model of the add on heat package is 7642-9151

i found the wiring diagrams and i will post pictures of what i have found so far , i think its just wired wrong and putting too much current on one pole of the breaker

 

[joel63]

What's the KW rating of the heater?

 

[Denwad]

i believe it is 15kw

{EDIT}

I can't get any pictures right now but coming off the breaker into the unit there are two more circuit breakers ( each 60 amp ) and i cycled them both, and now it seems to be running fine.

 

[keelan]

15 kW/240 V=62.5 A

Also, the safe working load for a breaker is 80% of its rating, so 48 A is typically the max for a 60 A breaker.

Working back from the figures you gave us:

59.7 A / 80% = 74.63 A

Seems you'd be more suited to a larger breaker.

 

[pseudorealityx]

15 kW/240 V=62.5 A

Also, the safe working load for a breaker is 80% of its rating, so 48 A is typically the max for a 60 A breaker.

Working back from the figures you gave us:

59.7 A / 80% = 74.63 A

Seems you'd be more suited to a larger breaker.

Depends on the type of electrical load. On many strip heaters, the MCA is very close to the breaker size. I was sizing some yesterday at work with an MCA of 44 and a 45 amp breaker.

 

[joel63]

Are you able set up the heat strips in to 2 stages.
One running 5 kw, and the other at 10 kw?
You would have to run 2 circuits from the power panel to the heater control panel and then use a thermostat with 2 stage heat control.
The installation instructions might cover a set up like this.

 

[bazar01]

Are you able set up the heat strips in to 2 stages.
One running 5 kw, and the other at 10 kw?
You would have to run 2 circuits from the power panel to the heater control panel and then use a thermostat with 2 stage heat control.
The installation instructions might cover a set up like this.

Good advise.

To the original poster, If the unit still trips the 60A breaker, and you want a quick solution so it works on the existing set up, just diasable one of the three 5kW heat strips. You will still have 10kW and drop the amperage draw. Put a note inside the unit so you will remember in the future what revision was done.

 

[crazy wheel]

15 kW/240 V=62.5 A

Also, the safe working load for a breaker is 80% of its rating, so 48 A is typically the max for a 60 A breaker.

Working back from the figures you gave us:

59.7 A / 80% = 74.63 A

Seems you'd be more suited to a larger breaker.

only if the power wire is sized for it, otherwise the wiring will become the fuse

 

[crazy wheel]

Hello gentleman I have a Coleman Suncutter with a addon electric heat package ( 59.7 amp draw ) and it constantly trips the 60 amp breaker its attached to.

I've opened it up and inspected the heating elements, no problem there, and i've checked the circuitry and wiring and nothing seems burnt.

its clearly drawing too much current but i haven't a clue why.

any clues where to look?

the model of the packaged a/c unit is 7430A601 and the model of the add on heat package is 7642-9151

i found the wiring diagrams and i will post pictures of what i have found so far , i think its just wired wrong and putting too much current on one pole of the breaker

I think you need a qualified electrician to evaluate the wiring to your heater.

15kw usually requires a larger electrical supply than a 60amp circuit.
I commonly see a 60amp circuit and a 30amp circuit for 15kw

 

[Denwad]

@crazy wheel

there is a separate 30 amp circuit, however i was under the impression that its for the a/c compressor section, i guess its necessary for the heater as well.

 

[Charles (in GA)]

Under the NEC electric heat is considered continuous and thus should never exceed 80% of the circuit breaker and wire capacity. Also, the NEC does not allow a heater to be protected at more than 60 amps per circuit. That is why larger heaters have more than one circuit supplying them.

Charles

 

[crazy wheel]

@crazy wheel

there is a separate 30 amp circuit, however i was under the impression that its for the a/c compressor section, i guess its necessary for the heater as well.

The a/c will need a circuit as well.