Air handlers - 2 on one circuit?

Status
Not open for further replies.

tonype

Senior Member
Location
New Jersey
Is it OK to supply 2 air handlers (fans for cooling systems, with cooling coils - no compressor) with a single 15-amp breaker? I never saw this before - usually, each a/h has a dedicated OPD.
 

Mr.Sparkle

Senior Member
Location
Jersey Shore
I am in NJ and have done this numerous times and never had a problem. Just check the specs but I'd bet 99.9% of the time you will be fine (speaking residential of course).
 

480sparky

Senior Member
Location
Iowegia
As long as there's no spec otherwise, and you don't exceed the ampacity of either the wiring method or the breaker.... go for it.
 

Buck Parrish

Senior Member
Location
NC & IN
Is it OK to supply 2 air handlers (fans for cooling systems, with cooling coils - no compressor) with a single 15-amp breaker? I never saw this before - usually, each a/h has a dedicated OPD.

The motors should have integral thermal or over load protection.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Is it OK to supply 2 air handlers (fans for cooling systems, with cooling coils - no compressor) with a single 15-amp breaker? I never saw this before - usually, each a/h has a dedicated OPD.

The crazy thing about this is if this were a heating unit-- gas furnace- you would need a separate circuit.
 

Karl H

Senior Member
Location
San Diego,CA
Funny, I just ran into this today while looking for another problem.

Two exhaust fans for fumehoods fed from one 208 single phase circuit.

#10 Thhn 26I both loads combined "continuous load". 196 volts at EF's.

30I warm and cozy breaker.
 

Mr.Sparkle

Senior Member
Location
Jersey Shore
The crazy thing about this is if this were a heating unit-- gas furnace- you would need a separate circuit.

Dennis,

forgive my ignorance but can you point me in the right direction in regards to where I can find this information cause I may deserve a smack on the back of the head.....shhhh don't tell anyone.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Dennis,

forgive my ignorance but can you point me in the right direction in regards to where I can find this information cause I may deserve a smack on the back of the head.....shhhh don't tell anyone.
The article I was thinking about is 422.12-- seems like an odd place for it but...

422.12 Central Heating Equipment.
Central heating equipment other than fixed electric space-heating equipment shall be supplied by an individual branch circuit.
Exception No. 1: Auxiliary equipment, such as a pump, valve, humidifier, or electrostatic air cleaner directly associated with the heating equipment, shall be permitted to be connected to the same branch circuit.
Exception No. 2: Permanently connected air-conditioning equipment shall be permitted to be connected to the same branch circuit.
 
Last edited:

jumper

Senior Member
Is it OK to supply 2 air handlers (fans for cooling systems, with cooling coils - no compressor) with a single 15-amp breaker? I never saw this before - usually, each a/h has a dedicated OPD.

where i work we have these type of of installs. actually its usually 4 or five AHU on a circuit. each unit has a disconnect switch with a thermal overload fuse sized for the motor. quite common for offices and dorm rooms.
 
Status
Not open for further replies.
Top