Motor Disconnects

[petersonra]

So is a disconnect considered a panelboard if it only has one dp breaker

View attachment 2571636

Is it listed as a panelboard?

 

[david luchini]

So is a disconnect considered a panelboard if it only has one dp breaker

That looks like a circuit breaker enclosure to me, not a panelboard.

I would think there would be a listing for the maximum size circuit breaker that could be installed.

 

[jap]

Why couldn't you consider a Panelboard a "Circuit Breaker Enclosure" ?
Loadcenters and Panelboards also have a listing for the maximum size circuit breakers that can be installed in them.

In that breaker enclosure it would all depend on whether you are mounting a breaker inside of it, or , if you are installing a breaker onto the buss bars of it.

There's a difference.
In one scenario you are landing the conductors on the lugs of the buss bars.
In the other you are landing the conductors on the feed thru lugs of the breaker itself as in and actual "Enclosed Circuit Breaker".

I doubt the breaker enclosure shown would have a separate ground and neutral bar that could be bonded or separated to be used with service conductors or feeder conductors like that of a Loadcenter or Panelboard.

Oh well,,,


JAP>

 

[Dennis Alwon]

That looks like a circuit breaker enclosure to me, not a panelboard.

I would think there would be a listing for the maximum size circuit breaker that could be installed.

Here some more info-- total amperage of 60 amps. It doesn't directly state 60 amp max overcurrent protective device . Again, this is hypothetical as it came up in a discussion the other night at our monthly meeeting

Main Lug Load Center 60 Amp 1 " Spaces 4 Circuits Boxed​

• circuit breaker enclosure is rated at 60 amps max and will accept a variety of breaker options. two single pole breakers, one double pole breaker, or four 1/2-inch frame breakers with a total amperage of 60 Amps, the enclosure is outdoor rated,breaker not included.

 

[Dennis Alwon]

I guess it probably is not compliant however I don't see a safety issue in it.

 

[electrofelon]

But the buss is protected as the overload will keep the buss from seeing more than 38 amps or so.

Interesting question. If this is a panel board, does the overload count as the overcurrent protection required in 408.36?

 

[Dennis Alwon]

Interesting question. If this is a panel board, does the overload count as the overcurrent protection required in 408.36?

That was the real reason I brought this up. Interesting- obviously easy to fix and make compliant. I noticed that the particular disconnect I showed did not show a hp rating but who knows what is inside the enclosure. The other words were from the ad

 

[electrofelon]

That looks like a circuit breaker enclosure to me, not a panelboard.

I would think there would be a listing for the maximum size circuit breaker that could be installed.

I think if you look at those small two space things they are actually panel boards typically.

 

[jim dungar]

Interesting question. If this is a panel board, does the overload count as the overcurrent protection required in 408.36?

A motor overload relay does not provide short circuit and ground fault protection, however the upstream motor short circuit protection device could provide that protection to the motor disconnect. In 2017, the applicable reference was 240.9.

 

[jap]

Then there's this that some yayhoo could install where the overload would not be limiting all the current that could be taken from the buss bars.







JAP>

 

[kwired]

That looks like a circuit breaker enclosure to me, not a panelboard.

I would think there would be a listing for the maximum size circuit breaker that could be installed.

That probably has a bus to plug the breaker onto though, and possibly can supply more than one breaker like was pictured with the Quad breaker a few posts back. So it likely is listed as a panelboard.

A circuit breaker enclosure would be something you mount a breaker with terminals on each side the breaker and not a breaker that connects to a bus structure of any kind like a panelboard would have?

Dennis keeps calling it a disconnect which leads to a little confusion. He is using it as a disconnecting means for specific utilization equipment yes, but it wouldn't typically be called a disconnect in product catalogs and such it would likely be in panelboard or load center section in a catalog.

 

[david luchini]

Here some more info-- total amperage of 60 amps. It doesn't directly state 60 amp max overcurrent protective device . Again, this is hypothetical as it came up in a discussion the other night at our monthly meeeting

If this is a 60A load center it needs to be protected by a 60A ocpd. Installing a 70A c/b in it would do nothing for you if it was protected with a 60A ocpd upstream.

 

[jap]

It this is a 60A load center it needs to be protected by a 60A ocpd. Installing a 70A c/b in it would do nothing for you if it was protected with a 60A ocpd upstream.

Agreed. and, most of the older AC Breaker type disconnects I've come across are not actually amperage rated breakers to begin with.
They look like a breaker but have no amperage marking on the handle.
They are nothing more than a switch.

JAP>

 

[Dennis Alwon]

That probably has a bus to plug the breaker onto though, and possibly can supply more than one breaker like was pictured with the Quad breaker a few posts back. So it likely is listed as a panelboard.

A circuit breaker enclosure would be something you mount a breaker with terminals on each side the breaker and not a breaker that connects to a bus structure of any kind like a panelboard would have?

Dennis keeps calling it a disconnect which leads to a little confusion. He is using it as a disconnecting means for specific utilization equipment yes, but it wouldn't typically be called a disconnect in product catalogs and such it would likely be in panelboard or load center section in a catalog.

Correct I am using it as a disconnect. Again hypothetically, not a real life situation

The purpose was to see if a 100 amp overcurrent protective device can be installed compliantly, in a 60 amp enclosure when used as a motor disconnect. There could also be a 100 amp disconnect at the panel.

 

[wwhitney]

If you have an enclosure with busses but only one circuit breaker, it's not a panelboard, per the Article 100 definition. So if supply conductors land on the circuit breaker lugs, and the bus ampacity exceeds the equipment MCA, while the circuit breaker does not exceed the equipment MOCPD, I see no code violation.

Cheers, Wayne

 

[electrofelon]

If you have an enclosure with busses but only one circuit breaker, it's not a panelboard, per the Article 100 definition. So if supply conductors land on the circuit breaker lugs, and the bus ampacity exceeds the equipment MCA, while the circuit breaker does not exceed the equipment MOCPD, I see no code violation.

Cheers, Wayne

Those two circuit thingys are indeed panelboards. I am not sure if there is a conflict with the article 100 definitions and UL 67, but my first thought is if you have a two space one, that could take two breakers , and I dont see putting a two pole breaker in as changing the listing to a different product.

 

[wwhitney]

Those two circuit thingys are indeed panelboards.

It may be listed as a panelboard, and that would cover the case of putting two single pole breakers in it. But if you put one double pole breaker in it, then it does not meet the NEC definition of panelboard. So Article 408 does not apply.

The fact that you could use the same piece of equipment in a different fashion is immaterial. Just like EMT is listed as a raceway, but you can still use it without conductors to build a trapeze to support other equipment or conduits (no idea if that's a realistic example).

Cheers, Wayne