Electrical disconnect clearances

[Jgkopp]

Being a former HVAC contractor, I see a need to inform the HVAC community of required electrical clearances. This drawing I did helps to illustrate and inform the HVAC contractor and I plan to post this information on a couple HVAC forums in the interest of educating them as they are selecting a suitable location for the outdoor unit. Looking for feedback here if this document Looks correct enough to publish.
The only questionable item in my mind is if there are other items routed through the working space is this allowed. Being the refrigeration lines are related to this installation I figured it was acceptable to have lines routed within a 6" space along the wall. On your forum, I am not sure if I selected the correct section for this post?
Thanks for your anticipated feedback.
John

 

[kwired]

If the disconnect has no overcurrent devices in it many places don't require 110.26 working space here.

NEC is a little vague on exactly what requires such working space, as worded every junction box possibly could be required to have such space, but we seem to mostly focus on switchboards, panelboards or motor control centers and such and let everything else be when it comes to working space.

Then there is dedicated equipment space where items foreign to the electrical system aren't allowed at all. HVAC guys tend to violate those requirements occasionally.

 

[WA_Sparky]

If the disconnect has no overcurrent devices in it many places don't require 110.26 working space here.

NEC is a little vague on exactly what requires such working space, as worded every junction box possibly could be required to have such space, but we seem to mostly focus on switchboards, panelboards or motor control centers and such and let everything else be when it comes to working space.

Then there is dedicated equipment space where items foreign to the electrical system aren't allowed at all. HVAC guys tend to violate those requirements occasionally.

Just curious, I've always assumed ATS's have to follow that rule as well. If there isn't OCPD/s in an ATS, does that mean you dont need to plan for working clearances?

 

[Jgkopp]

If the disconnect has no overcurrent devices in it many places don't require 110.26 working space here.

NEC is a little vague on exactly what requires such working space, as worded every junction box possibly could be required to have such space, but we seem to mostly focus on switchboards, panelboards or motor control centers and such and let everything else be when it comes to working space.

Then there is dedicated equipment space where items foreign to the electrical system aren't allowed at all. HVAC guys tend to violate those requirements occasionally.

I agree with you. I spoke directly with Mike several years back and received zero exception to the 110.26 req. clearance, even if it's just a disconnect box without overcurrent protection. My argument was what about disconnect switches in a closet for an air handler? It's a light switch? If one has nothing to service such as fuses I also believe 110.26 working space shouldn't be applicable however, the disconnect box access should not be blocked ether.
It seems to be a grey area as one could turn off the electrical circuit to perform work inside of it much like working on other electrical boxes. I guess the code doesn't really get into it. If you ask me this is an area that needs direction as 110.26 seems overboard. We have a city that req. 110.26 no matter if it has overcurrent protection. All of our other cities didn't have this issue however, it couldn't be located behind and blocked by the equipment.
John

 

[dkidd]

Also consider IMC:

306.1 Access.

Appliances, control devices, heat exchangers and HVAC system components that utilize energy shall be
accessible for inspection, service, repair and replacement without disabling the function of a fire-resistance-
rated assembly or removing permanent construction, other appliances, venting systems or
any other piping or ducts not connected to the appliance being inspected, serviced, repaired or
replaced. A level working space not less than 30 inches deep and 30 inches wide (762 mm by 762
mm) shall be provided in front of the control side to service an appliance.

 

[infinity]

Here in NJ there is no requirement to provide working space for an AC unit disconnect. Regarding your graphic in 110.26 there is no allowance for the refrigeration lines to be within the working space.

 

[kwired]

Just curious, I've always assumed ATS's have to follow that rule as well. If there isn't OCPD/s in an ATS, does that mean you dont need to plan for working clearances?

Again because of how vague NEC is on this it is up to local AHJ interpretation. You would think an ATS maybe has higher chance of them wanting it though.

Key phrase in 110.26(A) is "likely to require examination, adjustment, servicing or maintenance while energized". That can apply to just about anything that is intended to carry current.

You could certainly clamp an amp meter around a conductor(s) in a pull box with no splices/terminations in the box and say this is examination of some sort and deem the clearance should apply here, though there are many many junction/pull boxes all over the place that don't meet the working clearance requirements.

As written NEC leaves this pretty wide open as to what it should apply to.