Clearance above a light switch

[jumper]

I disagree with you assertion that voltage testing should not be considered examination. Voltage testing is the epitome of "Examination". I agree with Kwired. The key difference between a wall switch and an A/C disconnect IMHO is the term "Likely to be examined while energized". My opinion is that a disconnect is the most likely location for voltage testing while servicing an A/C unit while a wall switch would not be a likely place to test for voltage for servicing a luminaire.

JMHO,

Chris

Ditto. First place I check before I start pulling the HVAC covers off is the disco. Rule 1, check your source.

 

[Strathead]

How do you replace disconnect fuses without being exposed to live parts, unless you have turned the breaker off?

In the modern disconnects I am familiar with, the disconnecting blades remove power from the line side of the fuses. The incoming lugs are covered to prevent incidental contact. You have to work to get to an energized metal part. YOu are not exposed to live parts, any more than you are exposed to live parts when you plug in a vacuum cleaner.

So, to answer your question, you turn off the disconnect, open the door, replace the fuse. If your safety department has a concern beyond that, then all the clearance in the world isn't going to make a difference, your policy just needs to be "turn off the breaker." anyway.

 

[Strathead]

I disagree with you assertion that voltage testing should not be considered examination. Voltage testing is the epitome of "Examination". I agree with Kwired. The key difference between a wall switch and an A/C disconnect IMHO is the term "Likely to be examined while energized". My opinion is that a disconnect is the most likely location for voltage testing while servicing an A/C unit while a wall switch would not be a likely place to test for voltage for servicing a luminaire.

JMHO,

Chris

I don't know how you can say that a wall switch is not a likely place to check for power when servicing a lighting problem. Switches are just as "likely" to fail as ballast, and more likely to fail than a breaker or a splice in a junction box. If an entire room is out, but not an entire circuit, I would immediately go to the light switch. A common failure point in my neck of the woods. Actually with a disconnect in my experience you have the switch off, and test for voltage on the hard to access incoming lugs. Failure of the fuses is tested with an ohmeter, and a non fused disconnect failure would be generally visible inspection. A switch on the other hand needs to be tested hot, open and closed. Operated while the plate is off and far more likely to fail in your hand. I believe that I have MUCH less potential for personal injury troubleshooting a disconnect than I do a light switch. I have Kleins ( now Klein strippers) and a voltage tester with a blown off tip (done by an apprentice but still my fault) to prove it.

 

[kwired]

It has been said before and I will say it again (or something similar anyway):

If you take 110.26 for what it says there is nothing that may not possibly experience examination, adjustment, servicing, or maintenance while energized, and therefore every fuse, breaker, switch, receptacle, junction box, luminaire, relay, contactor, utilization equipment, I don't know where to stop should need to comply with 110.26.

 

[jumper]

In the modern disconnects I am familiar with, the disconnecting blades remove power from the line side of the fuses. The incoming lugs are covered to prevent incidental contact. You have to work to get to an energized metal part. YOu are not exposed to live parts, any more than you are exposed to live parts when you plug in a vacuum cleaner.

So, to answer your question, you turn off the disconnect, open the door, replace the fuse. If your safety department has a concern beyond that, then all the clearance in the world isn't going to make a difference, your policy just needs to be "turn off the breaker." anyway.

You mean those black cardboard shields are actually still there when you show up? You are a lucky man, maybe 10% of the time for me.

 

[jumper]

I don't know how you can say that a wall switch is not a likely place to check for power when servicing a lighting problem. Switches are just as "likely" to fail as ballast, and more likely to fail than a breaker or a splice in a junction box. If an entire room is out, but not an entire circuit, I would immediately go to the light switch. A common failure point in my neck of the woods. Actually with a disconnect in my experience you have the switch off, and test for voltage on the hard to access incoming lugs. Failure of the fuses is tested with an ohmeter, and a non fused disconnect failure would be generally visible inspection. A switch on the other hand needs to be tested hot, open and closed. Operated while the plate is off and far more likely to fail in your hand. I believe that I have MUCH less potential for personal injury troubleshooting a disconnect than I do a light switch. I have Kleins ( now Klein strippers) and a voltage tester with a blown off tip (done by an apprentice but still my fault) to prove it.

I replace probably 50 ballasts for every bad switch. Just my experience though.

 

[jumper]

It has been said before and I will say it again (or something similar anyway):

If you take 110.26 for what it says there is nothing that may not possibly experience examination, adjustment, servicing, or maintenance while energized, and therefore every fuse, breaker, switch, receptacle, junction box, luminaire, relay, contactor, utilization equipment, I don't know where to stop should need to comply with 110.26.

I hate it when people bring common sense and reason to a thread.

 

[Strathead]

I replace probably 50 ballasts for every bad switch. Just my experience though.

So what? When all of the lights are out in a room it is unlikely to be a ballast. It is most likely to be a bad switch. That is what I stated. 110.26 applies to a light switch every bit as much as it applies to a disconnect.

 

[Strathead]

You mean those black cardboard shields are actually still there when you show up? You are a lucky man, maybe 10% of the time for me.

No, I mean the black plastic shields, and yes they are usually in place.

 

[Strathead]

It has been said before and I will say it again (or something similar anyway):

If you take 110.26 for what it says there is nothing that may not possibly experience examination, adjustment, servicing, or maintenance while energized, and therefore every fuse, breaker, switch, receptacle, junction box, luminaire, relay, contactor, utilization equipment, I don't know where to stop should need to comply with 110.26.

Regretfully the code uses the cryptic "likely to require" leaving everything up to interpretation. I, still contend that a voltage test is not an examination, otherwise it would have been a reasonable expectation that the authors would have stated testing in the list of items requiring clearance. Of course the other option is that they left it vague so that there was a way to point fingers whenever an incident occurred.

 

[Dennis Alwon]

I see it differently. Outside of a main panel there is very little that needs to be energized while working on it.

 

[kwired]

Regretfully the code uses the cryptic "likely to require" leaving everything up to interpretation. I, still contend that a voltage test is not an examination, otherwise it would have been a reasonable expectation that the authors would have stated testing in the list of items requiring clearance. Of course the other option is that they left it vague so that there was a way to point fingers whenever an incident occurred.

I agree that leaves everything up to interpretation.

I also believe that any equipment is likely to require some work done to it at some time - but it does not necessarily need to be done while energized.

Why isn't voltage testing included somewhere in "examination, adjustment, servicing, or maintenance", which is the wording used?

 

[charlie b]

I see it differently. Outside of a main panel there is very little that needs to be energized while working on it.

The issue is not "need." The issue is "likely." Some heavy handed lead maintenance person may very well pressure one of the junior employees to perform live work under the philisophy that the company cannot afford the down time associated with turning power off. Is that likely? Well, that is the key question.

 

[kwired]

The issue is not "need." The issue is "likely." Some heavy handed lead maintenance person may very well pressure one of the junior employees to perform live work under the philisophy that the company cannot afford the down time associated with turning power off. Is that likely? Well, that is the key question.

Actually it is the production managers that don't think the company can afford down time. :happyyes: