ECN Forum
Posted By: Sandro Live Power - 02/11/04 01:46 AM
Let's be honest here. I am curious as to how many of us work with live power? As in making live connections, working inside panels and switchgear, removing receptacles etc. Is there a threshold? Only up to 120V? 347? higher?
Posted By: jeffrose Re: Live Power - 02/11/04 01:55 AM
I work W/ live power all the time but not above 277V (like that is still safe!).ABC Always Be Careful unless it takes to long.
Posted By: HotLine1 Re: Live Power - 02/11/04 02:01 AM
We work "hot" only when it is absolutely required. Lock out/tag out, test, verify, and be safe.

John
Posted By: Electric Eagle Re: Live Power - 02/11/04 02:01 AM
Guilty as charged.

On residential work, I'm pretty bad about working hot. If there's a switch near by, I'll turn it off, but I'll replace that same switch while hot. I'm very carefull, rarely get shocked, and my tools don't have burn marks on them. However, while I don't require it, I do encourage my guys to turn off the juice.
Posted By: pauluk Re: Live Power - 02/11/04 11:19 AM
I try to switch off wherever possible, but I work live occasionally. That's on our UK supplies which are 240V to ground.

I also work live on much electronic equipment, including old tube equipment with high-voltage DC supplies, but that's a rather different story.
Posted By: Edward Re: Live Power - 02/11/04 05:48 PM
Sometimes you have to work it hot when troubleshooting. I work hot up to 120 Volts. Anyhting hire power has turn off.
I remember reading somewhere that majority of electricians get electrocuted by 120 volts vs higher voltages.

When you turn the power off that does not mean that it is off. You have to check it twice. I got shocked last week when i took wires off of three brakers in a panel. Apparantley there is a backfeed.

I hate it when that happens.

Edward
Posted By: Edward Re: Live Power - 02/11/04 05:49 PM
Anything higher.

Correction.
Posted By: SJT Re: Live Power - 02/11/04 07:48 PM
I allways work it dead. I have the Amprobe Pasar meter. It has a great record so far in telling me what ckt. breaker operates the device
I need to kill. Cost a few bucks, but it's real good. Also, if any one is working on a computer at the time, I would ask them to log off temporarily, just in case I knock that off too.
Better to work it dead when ever possible. You only go around once.
Posted By: wye-delta Re: Live Power - 02/11/04 11:48 PM
The standard is to work in dead circuit for safety.But sometimes we need to work on live circuit but an extra precaution must be made.If only in resedential wiring it is safe to work on circuit which is dead.But in some cases where I worked wherein power is essential and not to be interupted I become more safety minded, I see to it that I have a long sleve/cover all, safety shoes, gloves in short I isolate myself to earth by puting extra essential clothing.But I limit the voltage to 240V otherwise it is very dangerous working with higher voltage unless you are wearing proper protective devices.
Posted By: golf junkie Re: Live Power - 02/12/04 10:45 PM
When necessary, yes, we do it.
Posted By: electure Re: Live Power - 02/12/04 11:22 PM
Other than trained and educated linemen.[soapbox mode}
I do nearly all the troubleshooting for our company (10-30 employees).
I will only take meter readings and the like with the power turned on. Any other work requires deenergization.
I don't care if the customer doesn't like the inconvenience. A dead electrician in their business is a BIG nuisance.

The last company I worked for went out of business, partly because of the death of an employee and the resultant Workman's Comp
One of the 3 owners gave up the trade forever. He and several other people had to have counseling/therapy for more than a year after this occurred, and still have recurrent nightmares.

The fella, about 25 yrs old, and one of those "legend in his own mind" guys, was working on a live definitely against company policy, and instructed not to 277V lighting circuit, while atop a scissor lift, and got the hot wire at the same time as he contacted a piece of EMT. He fell about 30 feet after he was electrocuted.
He left a widow, and 2 sons without a Dad.

We have an absolute and strict LOTO program at the new Co. If we catch a "Cowboy" working something hot, his last check will be ready immediately.

It's no joke, and not something to be taken lightly.

If you're an employer, and don't require it from your guys, I have no sympathy for your future. If your an electrician, and don't require it for yourself, think about your family.
Some of you don't have any respect for your livelihood, nor your life.
I'll see if I can get some stats. [/soapbox mode]

Try stickin' this subject up on the "Safety" parts of this Forum, and see what you get!!...s
Posted By: Ryan_J Re: Live Power - 02/12/04 11:35 PM
Well said Electure
Posted By: DougW Re: Live Power - 02/13/04 03:24 AM
I'll 'fess to it.

Of course, I work primarily with 110 - and I only work hot on a very rare basis. Usually just changing a receptacle, switch, or some such, and only where there's a single conductor in the box.

Multiple "hots", or >110? Kill 'em. Kill 'em all. Just got an Ideal 61-090 voltage / continuity tester on clearance at Grainger, and it replaces 3 smaller testers I used to tote around (Non Contact Voltage presence, high voltage up to 600VAC/200VDC, low voltage as low as 24VAC/6VDC, and audible continuity)


Tried to import pic, but couldn't.


[This message has been edited by DougW (edited 02-12-2004).]
Posted By: Bjarney Re: Live Power - 02/13/04 04:22 AM
Electure sized it up well. Nowadays/with soon-to-be arc-flash evaluation, low-voltage live work does lose some urgency. Hopefully this will stave off some “hot-doggers.”

Folks that snivel about ‘critical’ data loss from an outage automatically move to the bottom of my priority list. ‘Forgotten’ notification becomes more appealing. [Sometimes I have to remind self-important cubicle dweebs that I am as liable as the regional electric utility for electric-service continuity. But—don't try that at an international-banking data center that has a 22-page switching order to keep everything in a scheduled outage scripted in detail.]

It’s generally a given that low-voltage work does not require 29CFR 1910.269 training, but there’s not much question recent 29CFR 1910.331-335 orientation will be scrutinized in a construction/industrial shock/flash incident.

OTOH, do you have ASTM class-0 gloves and protectors? When was their last test date?
Posted By: Attic Rat Re: Live Power - 02/13/04 01:50 PM
...We try and kill the power,when we can,otherwise we do work live..I've instructed my guys to treat a "dead" wire as if it were hot,and check the circuit,even if it is declared to be dead...
AR
Posted By: PCBelarge Re: Live Power - 02/14/04 12:14 PM
More electricians are killed by 120v wiring because so many work it live.
Electure has written a very good post on this subject. Remember your family when you are working. It is not too difficult to have power turned off in an office environment, just tell them it may short out so you are trying to be considerate of the people who may lose power [Linked Image]

BTW- the majority of lives lost are the younger and the older in our industry - younger don't know better, and the older don't know better!

Pierre

[This message has been edited by PCBelarge (edited 02-14-2004).]
Posted By: :andy: Re: Live Power - 02/14/04 03:16 PM
after getting shocked several times (never at work, always at home [Linked Image] ) i always work dead.

if i cant find the right breaker, i start research which one it could be and try a few... i dont risk my life for the stupidity of others, not marking their work.


[This message has been edited by :andy: (edited 02-14-2004).]
Posted By: LK Re: Live Power - 02/14/04 08:25 PM
Quote: "I work primarily with 110 - and I only work hot on a very rare basis. Usually just changing a receptacle, switch, or some such, and only where there's a single conductor in the box."

These words are the ones we wanted to put on Johns stone. He was 32 years old, and left a wife and 4 year old son.

When looking for a new employee, this answer helps save time in the interview.

Once he told another electrician, "What do you expect them to shut down the whole plant just to change a switch.

When you meet someone that takes this position, it is best to stay clear and stay alive.

electure,
Was that accident in Jersey ? Just 5 min. form my shop there was the same accident, he was working 277 hot changing ballast at food store, they claimed the manager told them, he needed the lights on so shoppers would not be in the dark. This accident was just 2 weeks after Johns accident.
How soon they forget.

[This message has been edited by LK (edited 02-14-2004).]

[This message has been edited by LK (edited 02-14-2004).]

[This message has been edited by LK (edited 02-14-2004).]
Posted By: Trumpy Re: Live Power - 02/14/04 08:31 PM
I'd agree totally with Electure.
There are very few cases where you have to "work live".
Even in commercial buildings, I've gone in before the "Office Hours" start to hook up wiring that I installed the day before, shutting down all power to the building in the process.
Also, there have been times when I have had to "deaden" half the district to joint a fallen HV wire, but hey, the people only lost power for a few minutes and I'm still alive to talk about it.
It all about priorities!. [Linked Image]
Posted By: LK Re: Live Power - 02/14/04 09:00 PM
Trumpy,
I think some of these cowboys, are afraid to take the proper route, they fear someone will think they are not a good electrician if they have to cut the power.
Johns wife, told us, he worked hot because other electricians would think he din't know what he was doing.
Posted By: big guy Re: Live Power - 02/14/04 09:36 PM
Most of the time i don't like to work on anything hot,But sometimes i have to and YES it has to be live. Why? trouble shooting is one reason alot of the time you need the power on to find the problem. Other times you need to work things live because of plant work, like putting disconnects on busways, this is nasty work in a plant that has been working for 60 yrs with 3inches of powder metal on the busways. Somebody has to do it. big guy
Posted By: LK Re: Live Power - 02/14/04 10:04 PM
Big Guy,
It is understood, that some things like trouble shooting requires the equipment to be operating. Bus Duct systems can, and often do have failures, It is best to follow the manufactures instructions with Bus Duct,if they say it is safe to connect hot , then it was made for that purpose, The ones that I worked with, warned not to plug into a hot buss.
Posted By: electure Re: Live Power - 02/15/04 12:21 PM
LK,
No the accident I mentioned occurred here in Southern CA about 3 yrs ago.

I've found many different statistics (none quite the same) regarding construction electrocutions.
Live work on 277V lighting does seem to account for a large number of accidents.
Posted By: iwire Re: Live Power - 02/15/04 01:41 PM
I posted some of the following in another forum.

I would really like to know how to figure out the real risks we are exposing ourselves to.

Here is what I am talking about.

I would like to know the real numbers of people working in our trade and the real number of accidents and fatalities caused by electricity to these and only these people.

Exclude all other accidents caused by faulty appliances and untrained persons etc.

With that we could find out a number, 1 death per 1000, per 10,000, per 100,000.

Now I could compare that to my risk riding in my car or the risk to a convenience store cashier (supposedly one of the most dangerous jobs)

I am in no way saying it can not happen to me, but most things safety related should have cost benefit analysis.

Look at the controversy with AFCIs

As Don would say we would be safer if we all drove tanks (I think he means unarmed ones [Linked Image] ) but would the cost be worth it.

Yes anything can be shut off, but the conditions we meet in the field, mislabeled panels etc can make it very difficult.

Here is a great example, I was working on a fire alarm system and found this.

[Linked Image]

What do I do here? Many unmarked 480/277 and 208/120 circuits mixed with the fire alarm conductors.

How would we handle this, tell the building owners you must shut off the main to work on the fire alarm system?

Lets live in the real world, you would quickly run out of customers as there is always other ECs that will work on this.

I also feel the application of common sense is lacking in the OSHA rules, should you try to bolt "fingers" on a 1000 amp bus bar to add a 400 amp OCPD live hell no.

Should I be able to open a panel and take some amp or volt readings?

I always will.

I have a hard time with blindly following the OSHA rules if I do not know all the facts.

Yes I know some people who have been injured / burned by electricity most where doing something extraordinarily stupid.

Quote
I do nearly all the troubleshooting for our company (10-30 employees).
I will only take meter readings and the like with the power turned on.

Scott you are no more impervious to electricity then anyone else.

Sorry for the rant but it is a real world out there and I have not seen anyone that complies with these rules 100%.

Bob (Trying to stay alive and get the job done) [Linked Image]



[This message has been edited by iwire (edited 02-15-2004).]
Posted By: electure Re: Live Power - 02/15/04 07:29 PM
Bob, I claim no immunity to electricity.
I do, though, see a world of difference between putting a clamp around ammeter around a conductor versus installing switches, plugs, and making connections while live. Hope that doesn't make me a big hypocrit.
(See the original Q on this thread)

The data you're asking about is exactly the kind I'm trying to find (without much success sofar).
I think you remember this same subject coming up on another web forum. There were mostly "no big deal" posts with the exception of yours, telling them to shut it off.
I'm glad we've a more conscientious group here. [Linked Image]
Posted By: Jps1006 Re: Live Power - 02/15/04 09:09 PM
I used to work more stuff live than I do now. It is mainly because of the type of discussions here that has made me second guess the wisdom in risking damage to tools and equipment, injury, and death. Also, a couple of well placed spatterings of moltent steel (on cheek, just below my unprotected bare eyeball) although noneventful, really made me think, although death is less likely when taking these risks, permanent maiming is more likely.

I've never done anything over 110 live. Well, I shouldn't say never, but those installs I don't think I'd ever do again. I even had a T-12 lamp blow up in my face changing a bulb live. Now I don't do that anymore either.

I'll confess, the little residential stuff, changing swtich or outlet etc. I'll still do live with certain precations, but nothing commericial. I think you're better off and more professional to have everyone log off and take five rather than try to be a hero and accidently kill what could cumaltivly add up to hours worth of work that gets wiped out because it wasn't saved.

As far as changing it hot because if I don't, the next guy will, let him. As I've gotten more experienced and more confident, I've realized there are different levels of profesionalism and expertise. The better you are, the less swayed you need to be by what the other guy is doing. You only need to explain why YOU do (and don't) do what you do. The grocery store manager that thinks he's got the store's best interest in mind by requiring you to do it hot, what would his bosses think, or their insurance provider, or their saftey department?

I think if more of the quality guys put their foot down, then the only guys left that will do it live would be the yahoo's and they will eventually proove themselves not worth doing business with (theoretically).

All in all, it's up to you to decide what is worth risk, and what type of people you want to work for. There is always a way to figure to work something dead. I think it shows very poorly of a person that puts prouctivity and convinence above the saftey of their contractors.

I've found that when I turn down working for those types, it frees me up to find better customers, and then I try to appreciate and hold on to the good ones I have.
Posted By: NJwirenut Re: Live Power - 02/16/04 02:06 AM
Besides troubleshooting, the only work I do hot is the cut-off and tie-in of an upgraded service entrance. And this gets the full PPE and insulated tools dragged out. The lineman's gloves and face shield make a certain impression on the customer, as well... [Linked Image]
Posted By: PCBelarge Re: Live Power - 02/16/04 02:26 AM
JPS
Very well written!!!
Experience does not only make us better at what we do, it instills the confidence that we 'exude'. Some customers can feel it and will trust us to do the right thing even if it means turning the power off.
As an example, we had a load problem at an office building that probably could still be up and running with the problem, but we told the owners that it had the potential to create even more of a problem. They had another contractor say the problem could be fixed without shutting the building down. Long story short, we shut the whole building down for 4 days and 625 employees had a 4 day vacation while we fixed the problem.

I myself have walked away from jobs, because I have seen first hand some terrible accidents and do not want to be part of it. Funny I am still working/making money without those jobs.

I know some people work for a corporate company that has a 'bottom line' and you want to keep your job, but for me I cannot justify working live in a box like the one in your post. There is absolutely no reason! If someone is willing to do such poor work as what I can see in the box Bob posted, how do I know there is not a skinned wire there that could end my career or life? It takes more courage to say no than to say okay. It has been mentioned "real world" situations, I say that if the percentage killed in our business is 1 in 100,000, that would be one too many.
I agree accidents happen, but it does not have to be at the cost of the 'bottom line'!!
Remember it is only a job.

Pierre
Posted By: iwire Re: Live Power - 02/16/04 02:45 AM
Pierre do you drive a vehicle to the job?

40,000 of us Americans die every year in autos and the number of injury's greatly exceeds that. Think about that number for a few minutes next time you are in the car, about 109 deaths a day.

I do understand there are more folks in cars than working with wiring.

All I am saying is life is full of risk and I would like to know what the risks are in relation to qualified people doing electric work.

Yes I have learned a lot and I am not as caviler about live work as I once was, I also except the fact that working around electricity carries certain risks, like someone leaving a skinned wire.

This is no different than a emergency room worker assumes some risk from blood borne pathogens even with the safety procedures.

Are you going to tell me you always comply with all the requirements?

Your men always shut down panels when adding circuits?

Like I said if things can be shut down I do so, the box above I will not be able to shut down, I will put on my gloves and face mask and do what I have to do, I could say no and the company would not retaliate.

Bob
Posted By: walrus Re: Live Power - 02/16/04 12:03 PM
I, for the most part, work strickly on gasoline equipment. I work in some locations that have 6 to 8 dispnsers, that pump 8 to 10 thousands gallons a day. Pretty busy, for the most part someone is pumping all the time. The panels are rarely marked, almost never marked correctly. Sometimes there is only one disconnect for several dispensers. I wouldn't have any business if I shut the place down to work. Simple as that. Their are rules and their are facts of life.

On another sad note






Ricky Thompson of Caribou gets his dressings changed on his burn wounds daily at Cary Medical Center in Caribou by Rhonda Bossie, R.N., who has special training in wound care.
Last updated: Saturday, February 14, 2004
Trial by Fire
Severely injured Caribou man trying to rebuild his life

Rick Thompson's scarred face cringed in pain and fear as he recounted details of the day when a fireball of 10,000 degrees Fahrenheit burned the clothes off his body and the skin off his muscles.


Walking to the table in his mother's small, second-floor apartment in Caribou, Thompson acknowledged a visitor and raised his arm slowly for a handshake, but asked that the squeeze of his hand be gentle.


The skin on his arms, hands, neck and face are pink, the color of new, tender flesh. His hands, covered with new skin, ache when he performs simple tasks. Getting into a car and driving is a huge undertaking as the chill of northern Maineýs weather exacerbates the pain.


Thompson, 48, faces months of daily, painful occupational and physical therapy and dressing changes at Cary Medical Center for injuries he suffered more than a year ago in an industrial accident at the Boralex Fort Fairfield Inc. electrical plant.


He learned recently that he might need more surgery soon to repair tendon damage in one hand. Thompson is getting stronger as each week goes by, he said, but his speech remains slow, the words easing out at their own pace.


Thompson was hospitalized for nearly 10 months for injuries that included second- and third-degree burns over more than 50 percent of his body after he was set on fire when a circuit breaker shorted out and blew at the Fort Fairfield biomass electrical plant Oct. 22, 2002.


When an 800-amp breaker went from 480 volts of electricity to about 32,000 volts, the explosion ignited his clothing and skin, according to a government report.


Thompson first was taken to The Aroostook Medical Center and then was quickly flown to Maine Medical Center in Portland. Three days later, he was at Boston's Brigham and Women's Hospital burn unit, considered one of the best in the world.


Kept in a medically induced coma for five weeks, the County man was still on a respirator when he woke up. He had nine skin-graft operations in Boston, and three more in Portland.


"I feel lucky to have survived the accident," Thompson said recently in the apartment he shares with his mother, Beatrice Maynard, in Caribou. "I came so close to death.
Posted By: Joe Tedesco Re: Live Power - 02/16/04 02:47 PM
Look at these images, write them down, and always follow them to be sure and stay safe!
https://www.electrical-contractor.net/jt/P1110004.JPG
https://www.electrical-contractor.net/jt/P1110005.JPG

Courtesy: Dupont Corp.

PS: The safest way is to work on equipment with the power off!
Posted By: ga.sparky56 Re: Live Power - 02/16/04 04:16 PM
I don't do much commercial work,but the few commercial customers I do have,understand that I don't do much live work.

I'm fortunate in the fact that I don't need to do it to keep my job,or to make it convienient for someone to make a few bucks while I work hot.

I do some residential troubleshooting hot,but less and less of it as the years go by.

Russell
Posted By: winnie Re: Live Power - 02/16/04 05:31 PM
As a non professional with zero formal training, I 'work hot' every single day, safely and without incident.

The reason is that my 'working hot' is limited to attaching and disconnecting cord connected appliances. Okay, something of a joke, because plugging in a toaster is not what a professional electrician is thinking of when someone says 'working hot'. But it really is relevant: working hot is different for each job considered, and the risks involved depend upon just what hardware is being dealt with, just what work needs to be done, just what skill level is available, just what safety hardware is in use, etc.

Just try plugging in an appliance with a bolted short. You will quickly realize that simply plugging something is not entirely safe, even though it is considered acceptable for non electricians to use plugs and receptacles. Carefully considered and planned, with appropriate safety gear, I believe that 'working hot' could be as safe as plugging something in.

On the other hand, it seems to me that in many commercial situations, 'working hot' is required only because of scrimping on necessary protection hardware. If that computer over there _needs_ to be up 24 by 7, and you _cannot_ shut it down, then it should be on redundant circuits with redundant power supplies, and the entire computer itself should have an off site fall over backup so that can take over the processing load in an emergency. If this computer doesn't have the necessary backup, then someone clearly doesn't think that it really is worth keeping on 24 by 7. If the computer _does_ have this necessary backup, then you can schedule down time for the circuit and make the repairs without 'working hot'.

In other words, it seems to me that 'working hot' is often necessitated by someone trying to save a few dollars, and this attitude is the same one that prevents spending more for the additional precautions that working hot should require. If professional electricians simply quoted higher rates for working hot, then I'd bet there would be less demand for the special service. Instead of saying 'I won't work hot.', you might say 'If I work the circuit cold, the job will cost $200 and take 2 hours. If I work the circuit hot, the job will cost $500 and take 5 hours.' In this situation, I would bet that most of the people demanding that you work hot would start figuring out how to shut down equipment quickly [Linked Image]

It does come down to the rather scary calculus of dollars spent versus lives lost, and IMHO you can't simply say that no price is too high to save a single life. The reason is that every resource that goes into protecting life in one way (say preventing electrocution) is a resource that doesn't get used elsewhere. Sometimes this means that we don't spend money protecting life because we want to spend that money lining some rich dude's pocket (a bad outcome, IMHO), and other times this means that we don't spend money protecting life in one case because we can spend that money protecting more lives elsewhere ( a good outcome, IMHO). I think that the car safety analogy mentioned above is a really good one to think about. If you could insure that the risk for a given job is lower than the risk of driving your car to the job, would you 'work hot'? How about driving a motorcycle to the job? What about if it were as safe as hang-gliding to the job? Alas, the numbers aren't out there to even hazard a guess at the relative risks [Linked Image]

-Jon
Posted By: iwire Re: Live Power - 02/16/04 09:24 PM
Jon I am glad you got what I was rambling about.

I am not advocating unsafe work practices.

I would just like to know the relative risks.

This statement goes along well with what is in my mind.
Quote
Just try plugging in an appliance with a bolted short. You will quickly realize that simply plugging something is not entirely safe, even though it is considered acceptable for non electricians to use plugs and receptacles.

There are many things that non professionals deal with on a daily basis that I as a professional can not.

That J Box picture I posted above should be safe to mess with as the conductors are supposed to be all insulated, just like plugging in power cords is considered safe because there should not be shorts.

I have changed my thinking greatly already, I work much safer now than ever before.

I was taught to work hot by a guy that had been taught to work hot and so on.

Now with formal safety training I have learned more about what can happen.

That said I still think some of the rules are a little extreme.

If I think to much about vehicle accidents I will be wearing a crash helmet and NHL goalie pads, just to drive to work. [Linked Image]

Bob
Posted By: LK Re: Live Power - 02/17/04 12:11 AM
The idea of working hot or killing the power, may be more of a judgement call.
Let's say you are changing a recpt. to change it hot when not required could be a bad call. When troubleshooting live circuits, you have to consider the conditions, such as working space, dangers of accidential contact, and condition of equipment you are working on, all these things require good judgement and an established skill set in your field. An experienced electrician, should know when conditions to work hot, are not acceptable.
The risk level that one will take is established with, level of skill and the way they judge the conditions.
Bob, showed a box in his post, I would not work that box hot, however this does not make his way of working wrong or my way right, I think if you polled a number of EC's you would find each had a different aproach on how they would work that box.
Posted By: pauluk Re: Live Power - 02/18/04 10:29 AM
Quote
I also feel the application of common sense is lacking in the OSHA rules, should you try to bolt "fingers" on a 1000 amp bus bar to add a 400 amp OCPD live hell no.

Should I be able to open a panel and take some amp or volt readings?

I always will.

I feel that much of the modern safety legislation tries to override common sense by imposing a rigid set of rules to all situations.

Would I open a live panel to reach in and take voltage readings, so long as I can do so safely? Yes, I do it regularly, and experience teaches me what situations can be considered safe to do this.

Would I work the panel live if to get at the parts I needed to reach meant sliding my bare arm down the side of an enclosure only a couple of inches away from 415V busbars? No, because to me that becomes an unacceptable risk.

To impose a rigid rule that nothing must ever be worked live ignores those cases where it is the only practical way to troubleshoot a problem or to adjust some piece of equipment. That doesn't mean that I'll do something live if in my experience to do so would put me at unnecessary risk.

In my telecoms work I've regularly adjusted transmitters and other equipment containing high voltage supplies live. There's no other way to do the job, but for equipment which needs to be adjusted live, it should be designed in such a way that access is possible without risk to the operator (or perhaps I should say without undue risk, since everything we do in our lives carries a certain element of risk).
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