EWH and AHU Disc's in small mech closets

[don_resqcapt19]

I know that different people have different ways of doing things but if I was checking voltages I would start at the last place I terminated the conductors and that would be at the appliance or equipment. I do realize that a lot of people will start in the middle but why they do that is beyond my comprehension.

I am not talking about troubleshooting new equipment. I am talking about a service person coming in to work on non-working equipment. The most reasonable place to start is the disconnect that is located at the equipment as it is normally easier to access the conductors there than in the equipment itself. Lacking visible evidence of a problem elsewhere, that is where I would start every time.

I have checked voltages in light fixtures, junction boxes, in the control panels of the equipment such as dryers, ranges and water heaters. Are the removable panels on these appliances required to have the working spaces also?

It is my opinion that the current wording does apply to light fixtures, junction boxes and just about anything else you can think of. I have made the point in the past that it is my opinion that the required kitchen counter top receptacles are a violation of this rule. The internal parts of an appliance are outside the scope of the NEC.

I remember once having an underground feeder that wasn?t working so we dug up the conductors in places to test. Was we supposed to open a hole that was 30 by 36 inches to do this testing?

Are buried conductors likely to be worked on energized? If so, then you can't install buried conductors.

In my most honest opinion I think that some try to make this harder than what it is intended to be. Where to do voltage test is a choice each person makes on their own.

The issue here is the code wording and the fact that CMP 1 refuses to accept any reasonable proposals to limit the application of the workspace rule. It looks like this will have to wait unti the 2017 code as I don't see any proposals for 2014 that would limit the application of 110.26(A).

 

[Ragin Cajun]

So, just where does a disconnect for an AHU in the crawl space or attic stand? :?

By the way, I finally talked with the AHJ regarding my problem and he didn't want to see disconnects in a closet that were behind the AHU, etc. as he has seen in the past (he made them move them). He wanted them to be at least visible and accessible to the point you could get them. I added a note to that effect. He will be back after CHRISTmas so I'll see if he likes my note "NOTICE: AIR HANDLER (AH) DISCONNECT: THIS DISCONNECT SHALL BE EASILY ACCESSIBLE, IN PLAIN SIGHT, AND NOT LOCATED BEHIND ANY EQUIPMENT. VERIFY LOCATION WITH AHJ BEFORE INSTALLING." What else can one do, especially in a crawl space??? And as for a closet, make the electrician mount them on the wall outside the closet - I think not!

One can argue that to strictly meet 110.26, it's impossible to have an AHU in a crawl space or attic. Well, that's not going to happen!



RC

 

[jwelectric]

I am not talking about troubleshooting new equipment. I am talking about a service person coming in to work on non-working equipment. The most reasonable place to start is the disconnect that is located at the equipment as it is normally easier to access the conductors there than in the equipment itself. Lacking visible evidence of a problem elsewhere, that is where I would start every time.

Just about all the field work I do now is service calls. I can?t remember checking the voltage in a disconnect in over 10 years. If the appliance isn?t working at all I start at the panel and then go to the appliance itself.

It is my opinion that the current wording does apply to light fixtures, junction boxes and just about anything else you can think of. I have made the point in the past that it is my opinion that the required kitchen counter top receptacles are a violation of this rule. The internal parts of an appliance are outside the scope of the NEC.

How many kitchen counter receptacles that have ?exposed live parts??
How many equipment servicing disconnects do you encounter on a daily basis that have exposed live parts?
Read the three conditions under Table 110.26 that gives the depth of working space. Each condition list ?exposed live parts?. If there are no exposed live parts then there is no need for the working space.

The issue here is the code wording and the fact that CMP 1 refuses to accept any reasonable proposals to limit the application of the workspace rule. It looks like this will have to wait unti the 2017 code as I don't see any proposals for 2014 that would limit the application of 110.26(A).

After going back a few code cycles and reading their comments I think they do accept the wording as it is printed, ?exposed live parts? and continue to reject a laundry list of equipment simply because a lot of the equipment do not have exposed live parts during normal operation no matter where one would decide to do a voltage test.
The NEC is not a book that someone would use to learn how to trouble shoot problems that comes from training. But then again if those charged with training does not know a safe way to trouble shoot problems then those being trained will not know either.

 

[don_resqcapt19]

Just about all the field work I do now is service calls. I can?t remember checking the voltage in a disconnect in over 10 years. If the appliance isn?t working at all I start at the panel and then go to the appliance itself.

And I, and most troubleshooters that I know, would start at the disconnect. I have never seen the HVAC service guy start at the panel.

How many kitchen counter receptacles that have ?exposed live parts??
How many equipment servicing disconnects do you encounter on a daily basis that have exposed live parts?
Read the three conditions under Table 110.26 that gives the depth of working space. Each condition list ?exposed live parts?. If there are no exposed live parts then there is no need for the working space.
After going back a few code cycles and reading their comments I think they do accept the wording as it is printed, ?exposed live parts? and continue to reject a laundry list of equipment simply because a lot of the equipment do not have exposed live parts during normal operation no matter where one would decide to do a voltage test.
The NEC is not a book that someone would use to learn how to trouble shoot problems that comes from training. But then again if those charged with training does not know a safe way to trouble shoot problems then those being trained will not know either.

If this rule only applies to live parts that are normally exposed, without opening or removing a cover, then it would apply to very very few items. That is not how I read the rule.

 

[jwelectric]

And I, and most troubleshooters that I know, would start at the disconnect. I have never seen the HVAC service guy start at the panel.

This just goes to show how much experience they have. The first place to look is to see if the overcurrent is tripped unless they are looking to pad the service call

If this rule only applies to live parts that are normally exposed, without opening or removing a cover, then it would apply to very very few items. That is not how I read the rule.

Here is the section we are discussing;

110.26 Spaces About Electrical Equipment.
Sufficient access and working space shall be provided and maintained about all electrical equipment to permit ready and safe operation and maintenance of such equipment.

(A) Working Space. Working space for equipment operating at 600 volts, nominal, or less to ground and likely to require examination, adjustment, servicing, or maintenance while energized shall comply with the dimensions of 110.26(A)(1), (A)(2), and (A)(3) or as required or permitted elsewhere in this Code.

(1) Depth of Working Space. The depth of the working space in the direction of live parts shall not be less than that specified in Table 110.26(A)(1) unless the requirements of 110.26(A)(1)(a), (A)(1)(b), or (A)(1)(c) are met. Distances shall be measured from the exposed live parts or from the enclosure or opening if the live parts are enclosed.

Note: Where the conditions are as follows:
Condition 1 ? Exposed live partson one side of the working space and no live or grounded parts on the other side of the working space, or exposed live parts on both sides of the working space that are effectively guarded by insulating materials.
Condition 2 ? Exposed live parts on one side of the working space and grounded parts on the other side of the working space. Concrete, brick, or tile walls shall be considered as grounded.
Condition 3 ? Exposed live parts on both sides of the working space.

If there are no exposed live parts then no depth of working space is required. The receptacles over the counter top have no exposed live parts.

Today?s no fuse disconnects used for items such as AC, AH units, Water heaters and the such have no live parts with the door open or cover removed.
Service panels, remote distribution panels, fused disconnects, motor control centers and such will have exposed live parts when opened.

It says what it says not what we want it to say or what we think it says, (Charlie?s Rule)

 

[don_resqcapt19]

Mike,
As always we are not going to agree. I see the code section as very poorly written and you don't. You will not change my mind and I won't change yours.

 

[don_resqcapt19]

This just goes to show how much experience they have. The first place to look is to see if the overcurrent is tripped unless they are looking to pad the service call ...

I will agree that the OCPD is often checked first, but finding it not tripped, I will not be taking the cover off the panel to check for voltage. I will be opening the disconnect and checking the voltage there, unless the cover on the equipment itself is easier to remove.

 

[jwelectric]

Mike,
As always we are not going to agree. I see the code section as very poorly written and you don't. You will not change my mind and I won't change yours.

I went back and read all the ROPs and ROCs on this section for the past 4 code cycles to see what the CMP?s views was on the matter. What I understand is that the working distances are from the exposed live parts in equipment that can?t be de-energized. NFPA publishes many documents and one revolves around the other. There is a reason why Safety in the Work Place is volume 70E and the NEC is volume 70. They go hand in hand. One depends on compliance of the other.

I will agree that the OCPD is often checked first, but finding it not tripped, I will not be taking the cover off the panel to check for voltage. I will be opening the disconnect and checking the voltage there, unless the cover on the equipment itself is easier to remove.

It must be just me but after checking to see that the overcurrent device has not opened the next place I go is to the piece of equipment itself. I open the disconnect and remove a cover then close the disconnect to do voltage testing at the unit not in the middle of the circuit.
Taking the panel cover off is the last step in my trouble shooting procedure, but checking for voltage in the disconnect is not my first either.

I suppose that the two of us checking for voltages is just the way that the CMP looks at this section. You have your method and I have mine. Both procedures are our choice and is not mandated by the NEC.

 

[iwire]

I went back and read all the ROPs and ROCs on this section for the past 4 code cycles to see what the CMP’s views was on the matter. What I understand is that the working distances are from the exposed live parts in equipment that can’t be de-energized.

If that is the case than 110.26 does not apply to anything as everything can be shut off.

It must be just me but after checking to see that the overcurrent device has not opened the next place I go is to the piece of equipment itself. I open the disconnect and remove a cover then close the disconnect to do voltage testing at the unit not in the middle of the circuit.

Yeah, it must be just you.

I think your continued assertions that people do not check for power at a disconnecting means as one of the first steps in troubleshooting is at best disingenuous but I suspect it is pure bull.

I suppose that the two of us checking for voltages is just the way that the CMP looks at this section.

Seeing as none of us are actually CMP members we do not know how they look at this section.

 

[kwired]

I know that different people have different ways of doing things but if I was checking voltages I would start at the last place I terminated the conductors and that would be at the appliance or equipment. I do realize that a lot of people will start in the middle but why they do that is beyond my comprehension.

I have checked voltages in light fixtures, junction boxes, in the control panels of the equipment such as dryers, ranges and water heaters. Are the removable panels on these appliances required to have the working spaces also?

I remember once having an underground feeder that wasn?t working so we dug up the conductors in places to test. Was we supposed to open a hole that was 30 by 36 inches to do this testing?

In my most honest opinion I think that some try to make this harder than what it is intended to be. Where to do voltage test is a choice each person makes on their own.

Where as well as how. There is nothing wrong with turning off the feed connecting the meter then turning the feed back on to check voltage. It may not be done that way very often, but that is a different topic.

I have an underground fault locator that would likely have saved you lots of digging in the underground feeder situation you described.

So, just where does a disconnect for an AHU in the crawl space or attic stand? :?

By the way, I finally talked with the AHJ regarding my problem and he didn't want to see disconnects in a closet that were behind the AHU, etc. as he has seen in the past (he made them move them). He wanted them to be at least visible and accessible to the point you could get them. I added a note to that effect. He will be back after CHRISTmas so I'll see if he likes my note "NOTICE: AIR HANDLER (AH) DISCONNECT: THIS DISCONNECT SHALL BE EASILY ACCESSIBLE, IN PLAIN SIGHT, AND NOT LOCATED BEHIND ANY EQUIPMENT. VERIFY LOCATION WITH AHJ BEFORE INSTALLING." What else can one do, especially in a crawl space??? And as for a closet, make the electrician mount them on the wall outside the closet - I think not!

One can argue that to strictly meet 110.26, it's impossible to have an AHU in a crawl space or attic. Well, that's not going to happen!



RC

I guess all I can say is inspector has made it clear where these disconnects will not go. On the wall outside the closet is not a NEC violation in general. How about a loadcenter flush in the wall outside the closet with a door - at least it looks a little better.

Just about all the field work I do now is service calls. I can?t remember checking the voltage in a disconnect in over 10 years. If the appliance isn?t working at all I start at the panel and then go to the appliance itself.

How many kitchen counter receptacles that have ?exposed live parts??
How many equipment servicing disconnects do you encounter on a daily basis that have exposed live parts?
Read the three conditions under Table 110.26 that gives the depth of working space. Each condition list ?exposed live parts?. If there are no exposed live parts then there is no need for the working space.



After going back a few code cycles and reading their comments I think they do accept the wording as it is printed, ?exposed live parts? and continue to reject a laundry list of equipment simply because a lot of the equipment do not have exposed live parts during normal operation no matter where one would decide to do a voltage test.
The NEC is not a book that someone would use to learn how to trouble shoot problems that comes from training. But then again if those charged with training does not know a safe way to trouble shoot problems then those being trained will not know either.

Disconnects and breaker panels don't have exposed live parts either until the deadfront is removed. Same with kitchen counter receptacles. Even more true with tamper resistant receptacles.




I also have never liked this section. There are too many times it is either difficult to comply or difficult to interpret just what is likely to require examination, adjustment, etc. while energized. That alone can be a splice in a junction box in a remote area of a crawlspace that a 150 pound man can access but a 275 pound man would never even get close enough to see it is there. (I can speak from experience here from both ends of the spectrum)

Part of the problem is NEC and 70E are not integrated together enough (I am not an expert of 70E but can still see some of this) 70E basically from my understanding has little reason to work on anything that is live while it is exposed, yet not all of the requirements in NEC totally follow this concept.

 

[augie47]

I have to say, my troubleshooting coincides with I-wire. I MIGHT look at the panel 1st, but with mis-labeld breakers and the often need to move 100 lb of crap to access the panel, etc, my first step is often to check the disconnect for voltage.
Often easier... nothing to me, few if any screws to take out.
To each his own.

 

[jwelectric]

And my point is that where one does the voltage testing is a choice of that person and is not mandated by the NEC. Myself I always look at the panel to see if there is a tripped breaker. I am not looking for any labeling of breakers just looking to see if one is tripped.

In more than 40 years of changing batteries in a flashlight I don?t remember many times that there was a problem in the servicing disconnect for a piece of equipment unless it had fuses.

Most of the time it is something integral to the equipment such as a relay or circuit board or an element that has burned out and it didn?t require me to do anything to the disconnect.

For anyone who knows anything about 70E just what are the approach boundaries for a 240 volt panel with the cover on? It is not until the parts are exposed that this comes into play and the same is true for 110.26 where the three conditions for depth of working space are outlined that the words EXPOSED LIVE PARTS are found. The voltage can be check at one of these disconnects by simply pulling out the disconnect and inserting the probes into those slots and there is no need at all to expose any live parts to do this voltage testing.

This is my take and no one here is going to change that so there is no need for me to continue this discussion unless the time comes for me to do work in your jurisdiction at which time we can discuss it future.