HEIGHT of an AC DISCONNECT pull out

[Pierre C Belarge]

I hope you meant this as a joke:-?

I was thinking a little more about the comment about climbing on top of the A/C unit. The disconnecting means is there not only for the technicians/electricians, but possibly for the consumer. I find it hard to believe someone would consider climbing on top of the unit is a good idea for any reason, let alone to open a disconnect.

 

[Pierre C Belarge]

In the application of the AC disconnect, the pullout is a simple Controller that, when operated, serves to govern, in a predetermined manner, the electric power delivered to the AC. That is, upon operation, the power is turned off.

The english language is such a strong tool.

As I read the above, I picture in my mind a description of a switch.

 

[kacper]

Jim you need to rewrite the question with as much details as possible.

 

[charlie b]

I did not intend the "climb on top of the AC unit" as a joke, per se, but rather as an extreme example of why Jim need not be concerned about the height of the disconnect. Nor was I discussing what may or may not be a good idea. I was discussing what the code does and does not allow.

And the pullout disconnect is not a "switch." It matters not that it has contacts similar to something that is a switch. It does not operate like a switch (i.e., up is ON, and down is OFF). Indeed, it is not an "on/off control device." You don't turn anything on by operating it one way, and you do not turn anything off by operating it in the other way. It is there to prevent power from reaching a component, without regard to the position of whatever component normally performs the on/off functions.

Want proof? Take a look at 404.3(A). A pullout does not meet the requirement that a switch must be externally operable. One operates a pullout by pulling its insides out, so it is not "externally operable." QED

 

[cowboyjwc]

I would have to agree with Bob and Greg on this one as well as what Gus said before about the 6'7".

The one inch was actually added because it made the mm's a round number.

 

[al hildenbrand]

A pullout does not meet the requirement that a switch must be externally operable. One operates a pullout by pulling its insides out, so it is not "externally operable." QED

When I pull the handle of a knife switch, I use the handle to pull the contacts apart.

For an AC disconnect, when I pull the external handle of the pullout, the internal contacts are seperated.

Walks like a duck, and quacks like a duck . . .

 

[al hildenbrand]

Indeed, it is not an "on/off control device." You don't turn anything on by operating it one way, and you do not turn anything off by operating it in the other way.

You've obviously never serviced an air conditioner compressor. . .

Before I remove the cover of the wiring compartment, I most definitely TURN OFF the power to the AC by pulling the AC disconnect. If the AC happens to be running, it won't be after I pull the disco.

And if I don't use the disco to TURN ON the power when I'm done, you can bet that my client will be very disgruntled with me and refuse to pay me.

 

[al hildenbrand]

It does not operate like a switch (i.e., up is ON, and down is OFF).

By that logic, any mushroom panic switch is not a switch. Push to one state, Pull to the other state.

 

[charlie b]

This one doesn't walk like a duck, Al. Read 404.3(B) again. But start at the title of 404.3: "Enclosure." It is telling you that the enclosure of a "switch" must be mounted in an enclosure that permits the switch to be "externally operable." That, in turn, means that without opening the enclosure you can open and close the switch. A pullout does not function in that way.

And yes, I have not done any AC work. If I did, I would turn off the equipment with the controller inside, and then I would turn off the breaker, and then I would open the disconnect. But in any event, putting the pullout back into place does not cause the AC unit to operate. Rather, that act merely permits the controller (inside the house) to cause the AC unit to operate.

 

[M. D.]

before this turns into a "big ooops":grin:

http://ulstandardsinfonet.ul.com/scopes/scopes.asp?fn=1429.html

Pullout Switches

UL 1429

1 Scope

1.1 These requirements cover non-enclosed and enclosed pullout switches of the detachable type.

1.2 These requirements cover pullout switches rated 600 V or less, 400 A or less, with or without horsepower ratings, and with or without high-available fault current ratings.

1.2 revised July 28, 2005
1.3 These requirements cover pullout switches mounted in complete enclosure. Such an enclosure may contain meter sockets or neutral assemblies or both.

1.4 These requirements also cover enclosed pullout switches intended for use as service equipment.

1.5 These requirements cover non-enclosed pullout switches for use as mains and branches in panelboards, switchboards, and the like.

1.6 This standard does not cover hinged pullout switches. Such switches are covered in the Standard for Enclosed and Dead-Front Switches, UL 98.

1.7 These requirements do not cover enclosed pullout switches containing more than one independent switch which are covered by the Standard for Panelboards, UL 67.

1.8 A product that contains features, characteristics, components, materials, or systems new or different from those covered by the requirements in this standard, and that involves a risk of fire or of electric shock or injury to persons shall be evaluated using appropriate additional component and end-product requirements to maintain the level of safety as originally anticipated by the intent of this standard. A product whose features, characteristics, components, materials, or systems conflict with specific requirements or provisions of this standard does not comply with this standard. Revision of requirements shall be proposed and adopted in conformance with the methods employed for development, revision, and implementation of this standard.

And please look at this
http://www.cooperbussmann.com/pdf/ba12803b-6101-44d6-adb9-c1688b318c68.pdf

And this one
http://www.boltswitch.com/146.pdf


and this

? UL Listed Without Deadfront
? UL Listed as Enclosed Pullout Switch UL 1429
? UL Listed to Canadian Standards
? Line and Load Terminals Fully Enclosed
? Type 3R Rainproof Enclosure
? Duplex Ground Connector
? One-Inch Concentric Knockouts
? 1∅, 240 VAC

I think it is considered a switch

 

[charlie b]

I think it is considered a switch

Good references, MD. Hard to argue against them. But just let me mention that the NEC rules regarding maximum height of switches pertain to what the NEC considers a switch. The NEC requires a switch to be externally operable, as I have already pointed out. The photos you provided tell me that you can't operate that device without opening its controller.

Part of what made the Big Oops thread a long discussion was the mingling of terms we commonly use in what I like to call "conversational English" with terms that are defined or controlled by the NEC itself. The UL may use the word "switch" in connection with the pullout device, and so too may a manufacturer, and I have no objection to either usage. But let's restrict the discussion of NEC code issues to the use of the NEC language.

 

[M. D.]

Well,. charlie ,..you can't blame a guy for trying

 

[M. D.]

I would like to add that ,while I believe that it would be considered a switch ,. If ever I needed someone to refute that claim,... I'm calling Charlie

 

[SEO]

This one doesn't walk like a duck, Al. Read 404.3(B) again. But start at the title of 404.3: "Enclosure." It is telling you that the enclosure of a "switch" must be mounted in an enclosure that permits the switch to be "externally operable." That, in turn, means that without opening the enclosure you can open and close the switch. A pullout does not function in that way.

Charlie what about panels, load centers etc. that have a door that has to be opened to access the circuit breakers? A pullout with a cover that has to be opened is no different . Weatherproof panels have covers that have to be opened are they in violation of 404.3 (A)? I think that externally operable means that you could open and close the switch or circuit breaker without removing the dead front.

 

[SEO]

Wanted to add this to my other post . Per definitions in Art 100 "Externally Operable" means capable of being operated without exposing the operator to contact with live parts.

 

[Jim W in Tampa]

WOW thanks for all the feedback. I have not installed it yet because after opening it i found the pullout is at the very top and makes it just under 7 feet. Yes i can reach it but many could not. I will look at it in morning and try to find a better location.

 

[PetrosA]

My 2 cents: To me, a pullout disconnect isn't a switch because it's not "operated" like a switch - i.e. once you pull out the handle, you can walk away from the enclosure with the handle in your pocket and no one will be able to turn the equipment on (unless they happen to have a compatible handle in their pocket). Then, when you go back to re-energize, you have to check which way you plug the handle in. If you put it in in the off position, did you just switch the de-energized equipment off? I don't think anyone would agree with that.

This Bussman flyer differentiates between switch and pullout in the technical descriptions:

Link to PDF

 

[al hildenbrand]

Steve,

That's a great point:

2008 NEC Article 100 Definitions
Externally Operable. Capable of being operated without exposing the operator to contact with live parts.

There is nothing said about things like circuit breaker panel cover doors or the weather shield cover of an AC disconnect pull out switch.

 

[al hildenbrand]

once you pull out the handle, you can walk away from the enclosure with the handle in your pocket and no one will be able to turn the equipment on (unless they happen to have a compatible handle in their pocket).

What about a "keyed" snap switch?

Insert the key and raise the key to the UP position (if a single pole) and the snap switch is indicating and ON. Down position of the key equals OFF.

I can walk away from the switch with the key in my pocket and no one will be able to turn the snap switch on (unless they happen to have a compatible key in their pocket).

A "keyed" snap switch is clearly a switch.

 

[M. D.]

I also thought it funny that "switch" was not in the definitions ,... here is what Marriam Webster has

Switch: a device for making, breaking, or changing the connections in an electrical circ

uit