Announcement

Collapse
No announcement yet.

Do you need clearance for a disconnect switch?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Do you need clearance for a disconnect switch?

    If the disconnect for a piece of HVAC equipment doesn’t have any fuses, then can you make the argument the switch will not require maintenance so that 3’ clearance isn’t required?

    #2
    The best argument I’ve heard for the clearance is: in the event of a death, Explain to OSHA or a jury why the clearance was not there.
    Tom
    TBLO

    Comment


      #3
      If you were trouble shooting a problem at the equipment would you check voltage at the disconnect? Note that besides the word "maintenance", "examination" is in there too.

      Roger
      Moderator

      Comment


        #4
        I agree with your argument but its up to the inspector.
        If there's no fuses, then you wouldn't ordinarily check the switch energized.
        John,

        Comment


          #5
          Originally posted by cppoly View Post
          If the disconnect for a piece of HVAC equipment doesn’t have any fuses, then can you make the argument the switch will not require maintenance so that 3’ clearance isn’t required?
          Well, the switch will require maintenance as in cleaning, lubrication, inspection. Does it require maintenance while energized? Assuming you meant "while energized":

          Not sure where the three feet is coming from.
          110.26.A.2 width is 30" (or the width of the equipment if greater) Which still is not necessarily enough to stand off to the side when operating.

          Or is the clearance you are discussing 110.26.A.1 Depth. Some of those are 3 feet. Reducing the depth seems like poor design. How are you going to get in there to operate the switch handle?

          Code minimums are not a great place to be.
          Without data you’re just another person with an opinion – Edwards Deming

          Comment


            #6
            Originally posted by roger View Post
            If you were trouble shooting a problem at the equipment would you check voltage at the disconnect? Note that besides the word "maintenance", "examination" is in there too.

            Roger
            My argument as well. Typically the first place you start when troubleshooting.
            Rob

            Moderator

            All responses based on the 2017 NEC unless otherwise noted

            Comment


              #7
              You never have to maintain the switch while energized. There is always another breaker where you can turn the circuit off to work on the switch. Put a breaker lock and you're good.
              They say I shot a man named Gray and took his wife to Italy
              She inherited a million bucks and when she died it came to me
              I can't help it if I'm lucky

              Comment


                #8
                OK so the AC unit is on the roof with the disconnect next to it, the panel is two floors below in a mechanical room, which are you going to test first to see if there is power at the unit?
                Rob

                Moderator

                All responses based on the 2017 NEC unless otherwise noted

                Comment


                  #9
                  Thanks.

                  I was referring to depth since it's about 6" short of the full 3' working depth. I agree about the code minimums but was wondering if it's a requirement for disconnects if you can make the argument it's not likely to be worked on while energized.

                  Comment


                    #10
                    Originally posted by cppoly View Post
                    Thanks.

                    I was referring to depth since it's about 6" short of the full 3' working depth. I agree about the code minimums but was wondering if it's a requirement for disconnects if you can make the argument it's not likely to be worked on while energized.
                    IMO this is where the NEC falls short. It gives us ambiguity that is open to interpretation when it should be clearly defined. For many, including myself, the disconnect is the first point of testing. I would check to see if the breaker were tripped if not then the next simplest thing to do is open the disconnect switch and test the terminals. I'm not going to remove all of the screws on the panel or at the unit to test for voltage when I can just open the door on the switch.
                    Rob

                    Moderator

                    All responses based on the 2017 NEC unless otherwise noted

                    Comment


                      #11
                      Originally posted by infinity View Post

                      IMO this is where the NEC falls short. It gives us ambiguity that is open to interpretation when it should be clearly defined. For many, including myself, the disconnect is the first point of testing. I would check to see if the breaker were tripped if not then the next simplest thing to do is open the disconnect switch and test the terminals. I'm not going to remove all of the screws on the panel or at the unit to test for voltage when I can just open the door on the switch.


                      If I were an inspector I would enforce it.

                      Roger
                      Moderator

                      Comment


                        #12
                        Originally posted by cppoly View Post
                        Thanks.

                        I was referring to depth since it's about 6" short of the full 3' working depth. I agree about the code minimums but was wondering if it's a requirement for disconnects if you can make the argument it's not likely to be worked on while energized.
                        But it is likely to be examined while energized.

                        The next part would be, do you have enough 110.26 clearance when opening the equipment to test it and work on it? At some point in trouble shooting odds are you will have to have access to energized
                        [COLOR=#000000]terminals[/COLOR]
                        .

                        Roger
                        Moderator

                        Comment


                          #13
                          Originally posted by cppoly View Post
                          I was referring to depth since it's about 6" short of the full 3' working depth.
                          That tells me that this is an existing installation. Is that right?

                          One could wonder how it was initially installed and how its permit inspection was passed. One might also wonder why the question is being asked now. Is this just something you came across, and are trying to learn whether it is code-compliant? Or is an inspector calling this out as a violation (perhaps because it was noticed while the inspector was inspecting some other nearby new work)?

                          I agree with those who say this item does require working clearance, and that 30 inches of depth is not enough. It would be interesting to learn whether it is possible to move something and thereby achieve code-compliance.


                          Charles E. Beck, P.E., Seattle
                          Comments based on 2017 NEC unless otherwise noted.

                          Comment


                            #14
                            Originally posted by cppoly View Post
                            Thanks.

                            I was referring to depth since it's about 6" short of the full 3' working depth. I agree about the code minimums but was wondering if it's a requirement for disconnects if you can make the argument it's not likely to be worked on while energized.
                            Yes, you probably can make a plausible argument that the box is not, "likely to require examination, adjustment, servicing, or maintenance while energized". The short depth meets code minimums. Plenty of small hvac has a local, non-fused, safety disconnect tucked up close. However, don't feel bad if the AHJ shows up and says, "Our interpretation is non-fused disconnects will likely require examination" This would be the troubleshooting mentioned in previous posts.

                            I've got one out there where the depth is ridiculously shallow with my name on it. It even has a placard that says "prohibited to open while energized".
                            That was a lot of years ago - I still don't like it. And yes, I'm sure that eventually someone opened it for T-shoot - or will, if it hasn't already happened.



                            Without data you’re just another person with an opinion – Edwards Deming

                            Comment


                              #15
                              Sounds like I'm the odd man out here but I see no need for working clearance. There are gobs of places that I've opened up boxes, switches, disconnects, et al that I have opened up for trouble shooting that didn't have required work space.

                              I'd rather see the A/C disconnect well mounted and in good shape when I go to open it up than worry about how much open space is around it.
                              If Billy Idol is on your playlist go reevaluate your life.

                              Comment

                              Working...
                              X