Intent of 110.26, as it pertains to ancillary equipment?

[ChuiMuro]

Greetings, and thanks for taking the time to read and/or reply!
In installing a UPS, with flex conduit whips to allow the unit to be moved out to 40", we recently failed an inspection.
The 40" whips allow the unit to be pulled out for servicing and any other maintenance.

110.26 reads to work with clearances around electrical panels.
With the UPS "in place" (~13" from the wall), it fails the inspection because the inspector considers the UPS as a panel, as it has breakers (AC input/AC output/DC Batteries) on the rear of the unit.
It is not favored to leave the unit pulled out, as it takes a bit of real estate (and in some locations, could blocks egress out of the room).

We've literally installed thousands, across the US...and this is the first time that we've encountered this interpretation.

Your thoughts/options are appreciated.
Thanks in advance.

 

[Dennis Alwon]

IMO, the inspector is reading this section too literally.

 

[jaggedben]

Is the UPS on a wheeled rack or something? I'm struggling to visualize from the description.

 

[ChuiMuro]

...example of the wheeled UPS in discussion.

 

[hbiss]

I think the inspectors reasoning is that if someone has to get at the breakers on the rear of the unit, the unit has to be pulled out. If there ever was an emergency, say the batteries were on fire or shorted, that isn't going to happen. Is it possible to turn the rack around so that the breakers are accessible?

-Hal

 

[ron]

Does the UPS literature require maintenance clearance on the rear or sides? If so, the AHJ has a good point.
Mobile temp clearance is not what 110.26 requires.

 

[jaggedben]

I think the inspectors reasoning is that if someone has to get at the breakers on the rear of the unit, the unit has to be pulled out. If there ever was an emergency, say the batteries were on fire or shorted, that isn't going to happen. Is it possible to turn the rack around so that the breakers are accessible?

-Hal

110.26 doesn't say anything about emergencies. I agree with infinity, I think the inspector is being overzealous. This is like when you have equipment that could be blocked by a door when the door is open. So you close the door when working on the equipment so it doesn't interfere with your working space. Such an arrangement is usually not considered a violation. In this case you move the rack if you need to get your working space.

 

[petersonra]

I think the inspector is right about working space being required. The UPS is certainly "electrical equipment".



It is also likely that at some point it will require energized work.

It has never been real clear to me that the code actually permits equipment to be moved to get the required clearance. IMO, since it does not say that the clearance cannot be achieved by moving the equipment, I say moving it is an acceptable solution to gaining the required space.

 

[ChuiMuro]

Thanks everyone, for your contributions to this dilemma.
Please find some responses and ideas, as applicable.

Does the UPS literature require maintenance clearance on the rear or sides? If so, the AHJ has a good point.
Mobile temp clearance is not what 110.26 requires.

The OEM UPS Planning and Operations manual states clearance as 13" from rear for "ventilation".

I think the inspectors reasoning is that if someone has to get at the breakers on the rear of the unit, the unit has to be pulled out. If there ever was an emergency, say the batteries were on fire or shorted, that isn't going to happen. Is it possible to turn the rack around so that the breakers are accessible?

-Hal

This may be an option, but the display screen is on the front, as is a door for the modules.
The input breaker is located in a separate panel within the room.

I think the inspector is right about working space being required. The UPS is certainly "electrical equipment".

View attachment 2551958

It is also likely that at some point it will require energized work.

It has never been real clear to me that the code actually permits equipment to be moved to get the required clearance. IMO, since it does not say that the clearance cannot be achieved by moving the equipment, I say moving it is an acceptable solution to gaining the required space.

This one is interesting, and I'll toss out another idea...what if the unit was fed by line cord and 60309 plugs, instead of the flex?
Then, this makes the UPS like any other 'removable' piece of equipment with a line cord.

 

[petersonra]

This one is interesting, and I'll toss out another idea...what if the unit was fed by line cord and 60309 plugs, instead of the flex?
Then, this makes the UPS like any other 'removable' piece of equipment with a line cord.

I don't think it matters.

IMO, since the code does not prohibit moving the equipment to get the required working space, it is allowed.

 

[tortuga]

Install a good old knife switch on a wall in a 110.26 location with a big sign, its a beautiful sight, easy to identify job done.


A basic concept in the NEC and OSHA pertaining to equipment (motors,transformers, HVAC, batteries etc) is that anyone (including your least able bodied worker) should be able to run up to a disconnect un-obstructed and quickly and easily throw a disconnect to de-energize equipment and fast.
110.26 applies to equipment when manufacturers make a terrible design mistake, incorporating the required disconnect *in* the equipment to reduce electrician labor costs.
I recently solved a similar issue with an AHJ by locating a 110.26 disconnect on the wall within sight of a non 110.26 PV inverter.
(Inspector and PV guy both happy PV got a bit of extra work)
If there is first a disconnect; equipment will never *need* to be serviced while energized, per OSHA.

I think manufacturers are being too eager to include everything and a kitchen sink in packaged equipment.

 

[Carultch]

If there is first a disconnect; equipment will never *need* to be serviced while energized, per OSHA.

I think manufacturers are being too eager to include everything and a kitchen sink in packaged equipment.

Externalizing the disconnect of the device does give you the OPTION of working de-energized for most work one might need to do. However, there is some work you might have to do energized. Such as testing operating voltages.

Integrating the disconnect is still a decent design. One situation it really helps with PV inverters, is when they are located on a rooftop throughout the array, and not grouped together. Grouping them allows the branch breakers in the PV subpanel to act as the requisite AC disconnect, but if they aren't grouped, each one would need an AC disconnect immediately adjacent to it. It is a convenience to have it built-in, so you do not need to separately install a disconnect at each one. No NEC rule prohibits you from adding your own externalized/redundant disconnect, if your intent is to give the option to completely de-energize it.

 

[tortuga]

Externalizing the disconnect of the device does give you the OPTION of working de-energized for most work one might need to do. However, there is some work you might have to do energized. Such as testing operating voltages.

If you have the option to disconnect the source of power that energizes the equipment at a 110.26 location within sight (not on the equipment) it is now unlikely the equipment will need to be serviced while energized. In the unlikely event a qualified person needs to service equipment while energized they can use their 70E training and experience to do so safely, and if needed they can first de-energize and lockout at the disconnect, then re energize for testing etc.
If a unqualified maintenance worker or first responder notices a problem with the equipment they have a easy to understand way to shut it off and lock it out.

Integrating the disconnect is still a decent design.

How about when you need to replace several faulty inverters on a sunny day and all of them have built in DC disconnects?
I'd rather pay $500 less per inverter and just put a knife switch next to each one like we do for transformers or motors.

 

[jaggedben]

If you have the option to disconnect the source of power that energizes the equipment at a 110.26 location within sight (not on the equipment) it is now unlikely the equipment will need to be serviced while energized. In the unlikely event a qualified person needs to service equipment while energized they can use their 70E training and experience to do so safely, and if needed they can first de-energize and lockout at the disconnect, then re energize for testing etc.
If a unqualified maintenance worker or first responder notices a problem with the equipment they have a easy to understand way to shut it off and lock it out.

...

Seems to me you are reading a whole lot into the code that it just doesn't say.

 

[tortuga]

Seems to me you are reading a whole lot into the code that it just doesn't say.

It would not be the first time,
Just offering my experience with the context of the word 'likely' in 110.26 with 70E requirements.

Definition of likely:
1 : having a high probability of occurring or being true : very probable

110.26 (A)
Working Space. Working space for equipment operating at
1000 volts, nominal, or less to ground and likely to require exami-
nation, adjustment, servicing, or maintenance while energized shall
comply with the dimensions of 110.26(A)(1), (A)(2), (A)(3), and
(A)(4) or as required or permitted elsewhere in this Code.

Regarding the original post:

In installing a UPS, with flex conduit whips to allow the unit to be moved out to 40", we recently failed an inspection.
The 40" whips allow the unit to be pulled out for servicing and any other maintenance.

110.26 reads to work with clearances around electrical panels.
With the UPS "in place" (~13" from the wall), it fails the inspection because the inspector considers the UPS as a panel, as it has breakers (AC input/AC output/DC Batteries) on the rear of the unit.

I would ask this AHJ if a disconnect on the wall within sight of the UPS in a 110.26 location would eliminate the high probability that the UPS would need adjustment, servicing, or maintenance while energized. I would be interested to know ChuiMuro's AHJs opinion.

 

[jim dungar]

Just offering my experience with the context of the word 'likely' in 110.26 with 70E requirements.

Too bad the definitions are not interchangeable.
Maybe it is time for NFPA70 to acknowledge that probable and possible are not synonyms, for most uses.