Prevention of Electrocution in Weather

[CHOLLA BOB]

I have had two licensed electricians look at the box and they both said it would be a good idea to upgrade, but were not too concerned. There were two dirt wasps nests in there and the breaker bars look corroded. This summer I was fixed on the house supply line and was going to have it megger tested or replaced and it turned out to be a bad breaker. I am starting to think this may be similar as 15 amp breaker stopped working this week. This box is a poltergeist and I will have it replaced with a main shutoff soon. It's why I am getting wary of getting shocked.

I worked at a school welding shop and heard all the oxy-acetylene tank 'knocked the valve off and created a missile flying through walls' stories, but did not know about exploding Mig capacitors. That was some week of close calls.

Can you become a human conductor while multimeter testing an exterior 240 RV plug with wet or frozen ground conditions?

 

[Ballvalve]

Dry socks, big rubber boots, white dry cotton gloves, thin rubber over, your truck bed mat, and a face shield.

But about 98% of us would not bother. But watch our for capacitors.

Mabe your fault is in that above ground splice, in which case you could fix it and re-use the wire. If not save the wire and scrap it for 3 bucks a pound.

 

[Sponsor]

 

[JWelectric]

Can you become a human conductor while multimeter testing an exterior 240 RV plug with wet or frozen ground conditions?

Wet or dry .

 

[Cacher_Chick]

Where I live, we call the power company and they come and remove the meter. When we are done the local electrical inspector does his inspection and leaves a "approved" or "not approved" notice. Once the job is approved by the inspector, we call the power company and they come and put the meter back in. If it is not inspected and approved, they will not put the meter back in. The system works good for us.

 

[Rich B]

Around here electricians routinely do a service change or some sort of work like that and the permit and inspection is done after the work is already done.....The inspector is not a full time employee of the town....Just a guy who is probably retired and does inspections for many towns in the area. My service was changed a year and a half ago and thats the way it was handled. I met the inspector and made the appointment with the town. He looked it over, panel cover was never removed...checked the grounding system and connections inside the house and that was it......$150 is what I was charged by the electrician for that permit.....

 

[CHOLLA BOB]

I was going to do a temp splice with the existing wires but Thursday is not to far away: the electrician is back from the holidays. As I live way out nowhere, past work here is an unknown. Looks like a meter pull used to be the way this box was worked on. Driving around the plains, I see a lot of similar poltergeist boxes. The electrician is willing to work with me on getting things straightened out. Number one priority will be a main switch over the new box so I can get all the electrical solid.

Sounds like the same with multi-metering sockets; stay insulated. On further shock situations: as I remember, a television cathode acts like a large capacitor which is how the old TVs without protective shell can kill. As to the electricity and death tread, aren't there certain types of low voltage shocks that are lethal by the nature of their wavelength? When a fluorescent ballast starts up, isn't there temporary high voltage which is dangerous?

 

[JWelectric]

there is high voltage the whole time on the bulbs

 

[CHOLLA BOB]

So a fluorescent fixture could be a dangerous fixture to work on? Ballast is always producing high voltage? I had met that maintenance worker who paralyzed his forearm muscles by conducting electricity from fixture through arm to steel scaffold.

 

[DonL]

So a fluorescent fixture could be a dangerous fixture to work on? Ballast is always producing high voltage? I had met that maintenance worker who paralyzed his forearm muscles by conducting electricity from fixture through arm to steel scaffold.

You should not touch the ends of the fluorescent bulbs when power is applied. Wearing Gloves and Eye protection is good insurance.

 

[DonL]

Can you become a human conductor while multimeter testing an exterior 240 RV plug with wet or frozen ground conditions?

Yes, But Good Meter Probes should give you the proper protection.

Wear gloves and do not hold your meter in your Bare hands.

 

[DonL]

In the Electricity and Death thread, jwelectric gives a good rundown on different shock categories. What is the best way to prevent getting shocked while working on a Main Breaker Box that has no main shutoff?

Other than what jwelectric taught you, A good rule of thumb is , Never Be Scared of what you are working on, if your are Scared then get a professional to do the work.


Electricity can be your Best Friend, But it can be your worst enemy, And needs Your Respect...


DonL

 

[DonL]

Server Error; To many Posts in a Row; Server ID BR549; User DonL


Happy Holidays All...

 

[Rich B]

I use a Fluke 83. The leads are rated for use up to 600 volts. The meter is held in a yellow rubber protective cover. I have never even remotely had a shock using it and I've owned it close to 20 years. I use it everyday on machine repairs and testing welders. It reads frequency or Hz or also known as cycles...a very important feature when working on engine driven welders and generators....

 

[DonL]

DC Hurts More than AC, I think.

I use a Fluke 83. The leads are rated for use up to 600 volts. The meter is held in a yellow rubber protective cover. I have never even remotely had a shock using it and I've owned it close to 20 years. I use it everyday on machine repairs and testing welders. It reads frequency or Hz or also known as cycles...a very important feature when working on engine driven welders and generators....

That is a nice meter Rich.

Not many people can afford nice meters like that.
I do think that they are Over Rated. For the price.

When working on DC systems like you do it becomes more of a danger.

DC will normally make you hold on, While AC will Kick you off and make you let go.

Them big Caps can shock your Butt, Even with power off. You only do it once.

They are nothing to play with. But the welder needs them to keep that big time current flowing.


Sometimes discharge is better than recharge...

 

[CHOLLA BOB]

Problem is I'm not scared, I enjoy this too much! My electrician said most people don't want to have anything to do with electricity. I like it. That's why I started this thread as wanted to review what I may be taking for granted, like using tires and plywood as a ground insulator, etc. I do realize that every move has to be measured. With this box, trying to work conductors into the breakers after the breaker is set, is cramped work. Slip the screwdriver into the breaker bar without rated gloves would be not good. As jwelectrics' first rule is no conductor when installing breakers, it made me reconsider. Removing and installing the breaker with conductors set in breaker, made the job easy. I guess those attached wires increase the risk of electrical path through the body.

When I worked the main this summer, the forums I was working on said it was normal to work with a live box, just be careful. After reading the local utility newspaper on how electrical is handle, I knew I should get a full review on this. A year ago, I decided to ride a green horse I was ground training, bareback with halter, as I had done many times before. Got my mouth ripped back to the chin after a runaway and some rodeo kicks. Neighbor said I need the proper equipment to prevent getting injured. Many horses and dogs respond to any wrong moves as does electricity. This horse has improved tenfold because I now understand what it takes and that's what I wanted to do here; find out before I really find out!

PS: I guess a good multi-meter protects user. I had a tough time finding a fuse for my Craftsman, so I bought a Harbor Freight disposable. I hope they care enough, but I doubt it. Will look for a better multi-meter. Thanks for mentioning!

"DC makes you hold on" I had heard this back. Is this true of 12V automotive? I always discharge any capacitor I am around, or avoid like the plague.

 

[DonL]

Problem is I'm not scared, I enjoy this too much! My electrician said most people don't want to have anything to do with electricity. I like it.
"DC makes you hold on" I had heard this back. Is this true of 12V automotive? I always discharge any capacitor I am around, or avoid like the plague.

When you get to comfortable You can let your guard down.

12 VDC from a Car battery is not enough voltage to shock you unless you put your tongue across it.

At around 48 VDC, It will get your attention.

 

[JWelectric]

"DC makes you hold on" I had heard this back. Is this true of 12V automotive? I always discharge any capacitor I am around, or avoid like the plague.

Understanding the effects of current on the body is a class in and of itself. At school we have two days of nothing but current and the human body. This takes 10 hours to present to the class.

A lot of people think that the voltage potential is what that does the damage and will stand pat on that no matter the amount of information that is presented to them.

Voltage is the amount of push that is given to a circuit. A 12 volt battery can push the electrons through a set amount of resistance easier than a 1.2 volt battery can. It is the movement of electrons through the human body that does damage.

The research done in 1956 that established the “Stoll Curve†is what is used in determining the amount of PPE (personal protection equipment) to be used by the user when working on live circuits today and what is used by both NFPA 70E and OSHA.
http://www.esps.ca/data/1/rec_docs/102_Oberon_WP_Understanding_the_Stoll_Curve.pdf

The human body can sense current at ~ .001 amps. The let go threshold is around .015 amps and death can occur at ~.15 amps. By multiplying the resistance of the human body times .15 you can see how much voltage it will take to be fatal. The average male at the age of 30 that is in prefect health with on injuries will have a resistance of about 10,000 ohms. That same person on a hot day while being sweaty will have a resistance of about 1,000 ohms.
http://www.osha.gov/SLTC/etools/construction/electrical_incidents/eleccurrent.html

It is not the voltage that holds it is the current. It doesn’t matter if it is AC or DC.

Then we have the arc-flash that needs to be addressed. The heat of an arc-flash can reach to 32,000 degrees F which is 9 times hotter than the surface of the sun. This can occur when the screw driver comes in contact with the live bus bar of the panel and then grounded or is close to the other bus bar.
http://www.duralabel.com/ppc/free-arc-flash-book-g.php?gclid=CJy2nseDm60CFRBb7AodPR6vng

So people please understand this and forget all you have been told about one will hold and the other will knock you away as this is nothing but some old wives tale someone who thought they knew was saying but is totally untrue.
Current causes the muscle to contract and this is where the holding comes into play and also where the heart gets its damage. The heart is nothing more than a muscle. The knocking away is nothing more than the muscle of the arm contracting and pulling the hand toward the shoulder that this knocking away comes from.

If all this were not enough we also have the contracting of muscle that causes the body to bend forward which brings us even closer to the live parts of whatever we are working on.

Now everyone have a safe and Merry Christmas

 

[DonL]

Thank You JW,


I would like to test that Theory, But I think that I will have too take your word for it. lol


Have a Great Day.

 

[Rich B]

In auto shop when I was a teenager..... (the mid 60's so you know I am no spring chicken,LOL)....My shop teacher once said a car battery can kill you......If you get yourself connected with copper in each and across your body in series between the battery + and the starter and cranked the engine over and could theoretically pass a lot of amperage like a big old Pontiac V8 from the 60's.....The amps would git you.....Your body is not going to conduct that amperage at that low 12 volts so it is theoretical....

Engine driven welders usually have about 60 to 100 volts OCV.....or open circuit voltage if you measure it at the output studs. Can be DC or AC depending on the machine and how it is set. I occasionally get stung by one but it;s not very often. Welders can get electrocuted from a machine and one big hazard is when they are working in a wet ditch with cables laying all over the place....They can get bit real good....

I have a story I tell once in a while and I'll tell it now.....it is a simple one and shows how easy someone can get shocked and why GFCI's are a real good thing that came along.

An old friend was pressure washing his small dump truck across the street from a gas station I worked at in 1980. He had a steam jenny machine they were called back then. The dump body was up and he was cleaning the frame under it. I watched him set the wand of the stem jenny down on the frame amd than go to open the door of the truck.....He immediately started to jump and buck like he was riding a wild horse......I knew something was wrong and raced across the street to him.....by the time I got to him he managed to let go....His hand was clamped around the door handle and he could not let go.......He was white as a ghost and his heart was pounding bad......I sat him down and knew exactly what must have happened. I followed the extension cord and sure enough the ground prong was missing. With it still there MAYBE the breaker would have tripped, than again maybe not...I was lucky I did not get zapped myself as there was water all over and the steam jenny had somehow had some sort of internal short and energized the truck frame.......It was a simple 120 volt powered machine.....

AC or DC....High enough voltage (potential) and even a fairly small amount of current flow thru your body can kill you....and your muscles DO contract and they don't care if it's AC or DC voltage....

When I work on welders with high tech PC boards and other components I am suppoed to wear a wrist strap to discharge any static I might have in my body that can harm sensative components, A static discharge from your finger can go as high as 3000 volts! I think of this during the dry winter months as it happens at home this time of year.

Welders and Plasma cutters have some circuitry in them that can produce 3000+ volts at 1 million cycles per second.....High Frequency. It cannot be measured with a Fluke......it will kill the meter....

Don I have owned my Fluke since 1993. I paid $300 for it. It has been rpaired and recalibrated about 2 or 3 times. It has been drop kicked.....dropped in a bucket of anti-freeze....and generally beat up and used everyday.
It still works....I don'lt think that is overpriced.....They do make lower priced models that read HZ and in my line of work that feature is a must have....Cheers...

 

[Ballvalve]

I have a Big lincoln dc welder on wheels with a ac outlet for about 20 amps. Runs on a Perkins dielsel. fantastic machine, and I have used it and the little lincoln red ac box for decades in all sorts of weather and conditions. Never got a tingle or shock under any crazy situation.

Perhaps you can elaborate on why these devices that generate such 'heat' electrically seem never to harm the human? Is it safe to weld in the wet dirt with a good pair of boots and gloves on?