PPE for Residential and light commercial HVACR work

[peter d]

I watch a lot of HVAC/R video on YT (for my own education) and I don't think I've ever seen one yet where the technicians wore any kind of PPE working in 480 volt control cabinets for racks and chillers. I would guess there is widespread ignorance about arc flash hazard and the necessity of using PPE in the HVAC/R trade.

 

[David Goodman]

Yes


^^^^^^^^^^^^^^^^^^
This is the best, most realistic answer



Completely untrue and while I don't think it would qualify as an "arc flash" to many, there have been cases of a heck of a lot of sparkin' , smokin' and flashin' at residential panels- think about when the panel cover is getting removed, main breaker is off, but cover comes into contact somehow w/ the unfused line voltage while still touching bonded can.

How often does the above mentioned scenario or a bona fide proven arc flash happen in a residence? Don't know or care and the op said he won't be in panels, though he probably will at some point.



HVAC people working on 480v or less equipment need cat 2 per 70E.

Thank you, your response verifies my thoughts on the matter. I recently went through Fluke's training on PPE requirements, and it was an eye opener. I do plan on using Cat. 2 protection. I will be laughed at by my peers, but oh well.

You are also right that I will do limited work in a main panel, not replacing equipment, but live testing for voltage drop to AC equipment. I'll let you "Sparky's" tell the owner that the meter has to be pulled to work on the panel if an issue is found.

 

[David Goodman]

I watch a lot of HVAC/R video on YT (for my own education) and I don't think I've ever seen one yet where the technicians wore any kind of PPE working in 480 volt control cabinets for racks and chillers. I would guess there is widespread ignorance about arc flash hazard and the necessity of using PPE in the HVAC/R trade.

I believe that is a very accurate statement.

 

[David Goodman]

I feel comfortable taking readings on 240/480. How can you do this de-energized; remote measurements?

Adding a circuit or changing a breaker in the same, not so much. We only have one customer with 480V, and two with high-leg delta services.

If you think 120V cant ruin your day, think again. I've seen services so bad that diffusing bombs would be less nerve racking.

At least you know about arc flash and can take appropriate safety measures. My first WW op job, part of our duty was racking breakers from poco to internal power and back, Never once were we told what jamming a 480V 600A breaker into a 3000A bus would do if shtf.

eta: face shield would be my first gear to grab regardless of what osha mandates.

I am looking into remote measurements using a meter like the Redfish iDVM or Fluke's FC series. Have electricians started moving in this direction for safety sake?

 

[fmtjfw]

Cat 2 for residential. Insulated tools, CAT-IV meters, rubber gloves for hot tests.

Cat 2 for residential. Insulated tools, CAT-IV meters, rubber gloves for hot tests.

When I discovered 70E (Safety meetings? we don't need no stinkin' safety meetings), I added Cat 2 long sleeved shirt and trousers to my prescription safety glasses, and 1000V (meterman's gloves and covers). Wore that day in and day out for maintenance in school buildings. Gloves for hot. When we worked on the 12kV overhead system with pad and pole transformers, I added 25kV lineman's gloves and covers, step potential boots, a hard hat, and collapsible hot stick.

When we were going to cycle the "never opened in the memory of man" 1200A 480V 3ph main bolted action switch to replace a failed feeder CB, I trundled out my orange bag full of PPE and put on the overalls, the jacket, the balaclava, the face shield and all the daily stuff for layered protection. It was a Saturday and the foreman (carpenter by background) had come out to watch. He was wearing a tee-shirt and shorts. We ran him out of the room and told him to stand outside the door and call 911 if he heard a bang.

Fortunately, nothing of interest happened.

I have seen arc-flash movies. I am adverse to pain. I told my partner "if the medevac chopper is coming in to fly me to the burn center, it is your job to shoot me in the head first".

One of the lower amperage, lower voltage, bolted action main switches would not close, previous electricians had disassembled the opening/closing mechanism and left the pieces on the floor of the electrical room (for years) and pounded the switch closed with a 2x4 and hammer. I never trusted any bolted action switch on the property not to be a bomb.

We also had a 3Ph 120/208V 200A safety switch fail by opening only two phases with the handle fully down. The actuating insulator broke. Same thing happened on a 12kV ganged air switch which sprinkled large chunks of insulator on my partner at the base of the pole who was opening it. The pieces hit his hardhat.

None of this crap had ever been maintained.

 

[David Goodman]

None of this crap had ever been maintained.

The town I work in, like most I'm sure, is full of properties where either electrical equipment was installed improperly to being with, or where property owners have done their own work and modifications. I would love to have a qualified electrician perform an inspection on every job site, but that will never happen.

I need enough knowledge to know when to stop work immediately. Property owners might not appreciate that. However, it is for their own safety.

 

[user 100]

I need enough knowledge to know when to stop work immediately. Property owners might not appreciate that. However, it is for their own safety.

And yours too if you work on it.

If you are ever about to go into a situation with this work and see something that you think is unsafe/don't feel comfortable and have that little voice (that we all have) that says "stop" -listen. And that is no matter what anybody else thinks- ho/po has a problem, too bad. You can't force them to fix anything, but they can't force you to work on it.

That little voice just might save your life.

 

[petersonra]

Thank you for your response.

So, insulated tools and gloves might be advisable, but arc flash coveralls and face shield might be overboard?

At the least, one should wear the appropriate level 1 PPE. The coveralls and face shield may well be overboard for most single family residences.

I am not sure that I would use the word advisable. That implies to me that it is optional, and it isn't.

Your last sentence would indicate that PPE appropriate for the voltage should be worn even though the risk is low. I can accept that if it is the way to go. Even though HVAC contractors in Nevada are authorized to work on electrical supply all the way back to the power supply, I won't work inside the main breaker panel. I leave that for the electricians.

The low risk I was referring to was arc flash. note that I used the word substantial risk when referring to electrocution.

I don't know why you think it is unsafe for you to work in the main breaker panel but "safe" for you to work elsewhere. the appropriate precautions are required in either case.

 

[David Goodman]

I don't know why you think it is unsafe for you to work in the main breaker panel but "safe" for you to work elsewhere. the appropriate precautions are required in either case.

For me, changing out an HACR breaker in a main panel is beyond my area of knowledge. There are too many different types of breakers. Although I might find one that "fits", I might not realize that it is not listed for the panel I am putting it in. Also, many of the main breakers in the panels here cannot be trusted to return to working condition after they have been turned off. However, maybe that is a good way to make sure the deficiency gets corrected. If I throw a main breaker to remove a panel to test current and amperage to AC equipment at the main panel, and it then won't turn back on, then the HO/PO will have to call an electrician.

Here is a picture of one of those questionable boxes.

 

[petersonra]

For me, changing out an HACR breaker in a main panel is beyond my area of knowledge. There are too many different types of breakers. Although I might find one that "fits", I might not realize that it is not listed for the panel I am putting it in. Also, many of the main breakers in the panels here cannot be trusted to return to working condition after they have been turned off. However, maybe that is a good way to make sure the deficiency gets corrected. If I throw a main breaker to remove a panel to test current and amperage to AC equipment at the main panel, and it then won't turn back on, then the HO/PO will have to call an electrician.

Here is a picture of one of those questionable boxes.

I would point out that unless he looks it up the typical electrician would not know what the appropriate breaker or replacement breaker would be either in many cases. Looking it up is the only way to know. Sometimes it is as easy as looking at the labels on the box.

If the main breaker fails just by turning it off, you have done the HO a good turn by finding that out.

I have never heard of a main breaker in operating condition that fails merely by being operated by hand.

 

[iwire]

I have never heard of a main breaker in operating condition that fails merely by being operated by hand.

Yeah, some plug in mains will do that.

I have had them fall out when I removed the cover.

 

[David Goodman]

Thank you all.

 

[Fulthrotl]

Thank you all.

and thank you. ultimately, if you are in compliance with 70E,
you'll find it's a royal pain. a 40 cal. suit in july is no joke.
the suit's $1,500, and having one handy is a pain.

the laws are in place, 'cause inside each safety booklet that
you signed you read, is a little tiny attorney, folded up like
an origami jack in the box. if you violate those rules, *p00f*,
he pops out and shrieks, "FIELD CHECK".

none of the large shops i see permit hot work.
mandatory termination. is it still done, without PPE?

all the time.

 

[petersonra]

Yeah, some plug in mains will do that.

I have had them fall out when I removed the cover.

I can understand it coming loose, but to actually fail merely by being operated as the OP suggested?

 

[iwire]

I can understand it coming loose, but to actually fail merely by being operated as the OP suggested?

Plug in panel designs are marginal at best when new, once they get old and abused yes, breakers can literally fall out.

The old FPE stablocks relied in the cover to hold them in place.

 

[dinos]

So, insulated tools and gloves might be advisable, but arc flash coveralls and face shield might be overboard?

David,

Lots of responses to your question...forgive me if I provide information already discussed, but I wanted to provide a few tips based on arc-flash studies I have done and a certain amount of research.

There isn't a simple way to determine whether or not PPE is required, and to your question, whether or not coveralls and face shield might be overboard.

When I say "isn't simple" I mean in reference to either using the task based "tables" in NFPA 70E or a detailed incident energy analysis. Using the tables has the appearance of being simple, but there are very important underlying assumptions that could invalidate their usefulness. When someone walks into a facility "cold" and is faced with working on any number of panels/disconnects/etc how are they to quickly (i.e. cost/time effectively) supposed to determine what the available fault current is and what the upstream protective device tripping time is for the fault current at that particular equipment?

Don't let "low voltage" or "low fault current" fool you into thinking PPE is unnecessary. In some situations, lower values of fault current can result in higher incident energy as compared to higher fault current. This is because the lower fault current may take a longer time to trip the upstream device, and incident energy is proportional to arcing current and duration.

As an example, I just ran a quick analysis on a 100A, 240V circuit breaker, and for bolted faults between approx 730-1960A, the incident energy varied from 4.8-8.5 cal/cm2. Definitely worthy of PPE. For fault current higher than 1960A, the breaker is essentially acting in its instantaneous region, so is very fast with the cal/cm2 being much much lower (approc 0.05-0.18 cal/cm2).

The question becomes, how can you be sure of what the available fault current is at the equipment you intend to work on? That kind of information is likely not available to the homeowner, and many commercial buildings don't have that information at the ready either. If somebody feeds a piece of equipment in a garage or shed or whatever from their house panel and it is far enough away, you could see comparatively low fault level currents.

Practically, and this is just my opinion, you might want to consider always wearing at least category 2 PPE to provide some level of protection...I find that I can work somewhat comfortably in arc-rated 8 cal/cm2 coveralls (technically you don't need additional shirts and pants underneath). If the equipment has a detailed arc-flash label, read it carefully.

 

[petersonra]

I find that I can work somewhat comfortably in arc-rated 8 cal/cm2 coveralls (technically you don't need additional shirts and pants underneath).

Go commando and be even more comfy.

will be less clothes to scrape off of you after the arc flash that way as well.

 

[David Goodman]

David,

Lots of responses to your question...forgive me if I provide information already discussed, but I wanted to provide a few tips based on arc-flash studies I have done and a certain amount of research.

Excellent! Thank you for your input.

 

[JFletcher]

Plug in panel designs are marginal at best when new, once they get old and abused yes, breakers can literally fall out.

The old FPE stablocks relied in the cover to hold them in place.

QFT. They are very prone to falling out if there arent breakers below them to kinda wedge them in place when the df is removed. Total crap design even before FP forged/falsified UL listings.

 

[Sahib]

Yes. Follow the rules.

So you cannot answer the OPs question and all your posts in this thread have been wasting people's time.

Got it.

This is pretty stupid on your part.

The arc flash study and so full PPE is required for any equipment at 50V or greater.

However,

Arc flash studies and so full PPE are not required in homes that are single-family residences.