a/c disconnect

[dj94]

hi, i have a question about requirements for a/c disconnect.
i have an a/c unit 3p 208v 125a
there is a terminal block that splits to 4 internal breakers.

if these 4 breakers kill all power to the unit do i still need to install an
additional disconnect?

nec 440.14 (2005) "the disconnecting means shall be permitted to be installed on or within the equiptment"

 

[LarryFine]

I suggest checking with your inspector, but around here, the internal breakers suffice if they're accessible from outside the unit without tools.

 

[dj94]

thanks for you input larry.
hopefully a few more people will chime in!

 

[Volta]

thanks for you input larry.
hopefully a few more people will chime in!

I think the four are ok.

 

[Cavie]

two breakers are acceptible. that's how you keep the heat strip load to 60a each.

 

[dj94]

cavie
was your post relevant to my orginal question? am i missing somthing?

 

[Jim W in Tampa]

If its 6 throws or less i would think its ok. Rather see it that way than 4 disc panels
likely they are protecting compressor, fan motors, heat seperate but i would call the AHJ as its his opinion that matters most

 

[Cavie]

cavie
was your post relevant to my orginal question? am i missing somthing?

Nope you didn't miss a thing. I missed the right key. 4 breakers ok.

 

[Volta]

If its 6 throws or less i would think its ok. Rather see it that way than 4 disc panels
likely they are protecting compressor, fan motors, heat seperate but i would call the AHJ as its his opinion that matters most

I would not like to see too many separate switches comprising the disconnect means for HVAC equipment. But what would limit it to six?

 

[dj94]

thats the same thing i thought.
i think if i lable the 4 breakers inside "main" 1 of 4 2 of 4 etc. i'll be ok

 

[joebell]

440.14 contradiction?

440.14 contradiction?

440.14 states in the first sentence that "the disconnecting means shall be located within sight and readily accessible" but then it goes on to say that "the disconnecting means shall be permitted on or within". If the disconnecting means is within the equipment how is it within sight and readily accessible.

To the OP the only thing that I can see is 440.11 that says basically that the disconnecting means should be capable of disconnecting the equipment from the circuit conductors,but that is open to interpetation.

 

[iwire]

If the disconnecting means is within the equipment how is it within sight and readily accessible.

We wire RTUs all the time with internal disconnects but they can be operated from outside the unit, either through a little door that allows access to a breaker handle or there is an external handle that links to the internal disconnect.

 

[joebell]

We wire RTUs all the time with internal disconnects but they can be operated from outside the unit, either through a little door that allows access to a breaker handle or there is an external handle that links to the internal disconnect.

I do too Bob, the operating means for the disconnect is readily accessible. The Op mentions that the 4 CB' s are fed from a terminal block, the only time I have seen this is inside the equipment wiring compartment.

 

[Jim W in Tampa]

I would not like to see too many separate switches comprising the disconnect means for HVAC equipment. But what would limit it to six?

Maybe is no limit but is the number they use for service.