AHU's with built in breakers
- Thread starter ctmike
- Start date
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qcroanoke
Sometimes I don't know if I'm the boxer or the bag
- Location
- Roanoke, VA.
- Occupation
- Sorta retired........
Yes. Can't remember the article but I believe it says "mounted on or a part of"
kwired
Electron manager
- Location
- NE Nebraska
I have always considered that to be the main reason they are there in the first place.
They are certainly not needed for overcurrent protection most of the time.
- Location
- Tennessee NEC:2017
- Occupation
- Semi-Retired Electrician
I have a fairly new unit and on the air handler there is a breaker. There is a label above the breaker that states it is only a means of disconnect and not OCPD.
kwired
Electron manager
- Location
- NE Nebraska
That means it is not a breaker, it is a molded case switch.
- Location
- Tennessee NEC:2017
- Occupation
- Semi-Retired Electrician
I suppose, but it is an actual breaker. The label actually says " Circuit breaker is not intended for branch circuit protection. It serves as a disconnect only."
I know what you mean but you could remove the breaker and install it in a panel and it would work as an OCPD.
Allow me to muddy the water a bit 
Some of the AHUs I have inspected have a plastic cover over the
breaker/disconnects you reference. The cover is held closed by a screw.
Is this an acceptable disconnecting means ?
Some of the AHUs I have inspected have a plastic cover over the
breaker/disconnects you reference. The cover is held closed by a screw.
Is this an acceptable disconnecting means ?
AHU's with built in breakers
I have been told you can use the unit provided circuit breakers as the required disco, and I have been told you can't.
Never failed inspections useing them as a disco.
Reading 240.10 kinda gets me to thinking that it would be okay for disconnect but not for ocp.
I have been told you can use the unit provided circuit breakers as the required disco, and I have been told you can't.
Never failed inspections useing them as a disco.
Reading 240.10 kinda gets me to thinking that it would be okay for disconnect but not for ocp.
kwired
Electron manager
- Location
- NE Nebraska
Allow me to muddy the water a bit
Some of the AHUs I have inspected have a plastic cover over the
breaker/disconnects you reference. The cover is held closed by a screw.
Is this an acceptable disconnecting means ?
If the branch circuit breaker is within sight but behind a panel door with a latch or lock it is still acceptable for same purpose so why not?
- Location
- Lockport, IL
- Occupation
- Retired Electrical Engineer
My answer is yes to both. The disconnecting means is required to be "readily accessible." The definition of that phrase tells us that we have to be able to reach the disconnecting means quickly. But it does not tell us that we have to be able to operate it quickly (e.g., as an emergency shutoff).
The intent of "disconnect means within sight" is to be able to service a piece of equipment without some idiot turning the power on you.
Same reasons the on/of buttons on a range are allowed as means of disconnect(I know there's some additional requirements, so don't start).
Let's look at a connector/plug assembly. Been replacing 5-6 lately. Had to change the connector. Hey, where's MY means of disconnect. Personally I either have a helper stand by to make sure no one turns breaker on, or I take the panel cover off and take the wires off the breaker.
Same reasons the on/of buttons on a range are allowed as means of disconnect(I know there's some additional requirements, so don't start).
Let's look at a connector/plug assembly. Been replacing 5-6 lately. Had to change the connector. Hey, where's MY means of disconnect. Personally I either have a helper stand by to make sure no one turns breaker on, or I take the panel cover off and take the wires off the breaker.
highvolts582
Senior Member
- Location
- brick nj
I do not see how getting in an attic with a ladder is readily accessible yet the disconnect is always up there and never fails. within sight is what I go by.
- Status