Maximum height disconnect can be

[PhaseShift]

What is the maximum height a disconnect or breaker handle can be from the ground? I am referring specifically to a breaker disconnect handle on the front of a drive enclosure. What section of NEC is this?

Another question is I think you need 36" clearance in front of 480V panel by code. But what if 26" away from the front of the panel we had a cabinet on an adjacent wall that only stuck out a few inches in front of the plane of the 480V panel? Would this still count as a violation, or does the whole plane of the front of the 480V panel need to be blocked to be a violation if under 36"?

 

[KP2]

240.24 say's 6'7" to the center of the grip of the handle in it's highest position. Thier are some devices that don't apply, see 1-4.

The Clearence needs to be 36 inches and 30 inches wide or the width of the panel whichever is greater.

 

[raider1]

What is the maximum height a disconnect or breaker handle can be from the ground? I am referring specifically to a breaker disconnect handle on the front of a drive enclosure. What section of NEC is this?

6'7" to the center of the operating handle. (See 404.8(A))

Another question is I think you need 36" clearance in front of 480V panel by code. But what if 26" away from the front of the panel we had a cabinet on an adjacent wall that only stuck out a few inches in front of the plane of the 480V panel? Would this still count as a violation, or does the whole plane of the front of the 480V panel need to be blocked to be a violation if under 36"?

IMHO a 480 volt disconnect for a drive needs to meet the working space clearance specified in 110.26(A).

Chris

 

[Dennis Alwon]

PhaseShift]
What is the maximum height a disconnect or breaker handle can be from the ground? I am referring specifically to a breaker disconnect handle on the front of a drive enclosure. What section of NEC is this?

Ans

6'7" to the center of the operating handle. (See 404.8(A))

Chris how do you do this if the disconnect is in a dropped ceiling or crawl space. Obviously I may not be talking about the equip the OP stated.

 

[raider1]

Ans


Chris how do you do this if the disconnect is in a dropped ceiling or crawl space. Obviously I may not be talking about the equip the OP stated.

404.8 Exception #2 permits switches installed adjacent to motors to be located higher than 6'7".

This exception was put in to correspond to 430.107 that requires at least one of the disconnecting means required for a motor and motor controller to be readily accessible. This would permit the motor disconnect to be located above 6'7"

Chris

 

[Dennis Alwon]

Thanks Chris

That is new info to me but I was wondering why 110.26(A) would apply and not the others esp. 110.26(E). Also I find it interesting that (E) only applies to service equip., switchboards, panelboards, or motor control centers.

 

[raberding]

overcurrent prot

overcurrent prot

and, I believe that 240.24 related to Overcurrent Devices...not necessarily Disconnecting Means

 

[raider1]

Thanks Chris

That is new info to me but I was wondering why 110.26(A) would apply and not the others esp. 110.26(E). Also I find it interesting that (E) only applies to service equip., switchboards, panelboards, or motor control centers.

The reason that I would say 110.26(A) would apply to this situation is the likelihood that the disconnect would be the location a service tech would check for voltage. Also when complying with 70E and performing a LOTO procedure you assume that the disconnecting means is energized until a voltage test if performed to verify that the disconnect is in an electrically safe work condition.

As for 110.26(E) as you pointed out only applies to service equipment, panelboards, switchboards and motor control centers and does not apply to disconnects.

Chris

 

[raider1]

and, I believe that 240.24 related to Overcurrent Devices...not necessarily Disconnecting Means

Correct, unless the disconnect contains fuses. That is why I referenced 404.8 which would apply to a non-fused or fused disconnect switch.

Chris

 

[PhaseShift]

What if we put a step or small platform in front of this drive so that when on the platform the distance to the center of the breaker is less than 6'-7"?

 

[wasasparky]

The Clearence needs to be 36 inches and 30 inches wide or the width of the panel whichever is greater.

Might even need 42" or 48" depending on what faces the 480V panel.