QOD 11-1-2006 Electrical

[Greg Bell]

Thanks for all the discussion about this question. I am sure that many NACHI members will learn from it.

[Richard L. Bennett]

Paul


We are off the time gap of posting -- you say one thing and I say something else and before the other one responds the other one says something that is not relevant to the post

So welcome to the Internet

In short I follow your Ohms law logic

Now back to the HI and the Ele. world

Do we change our MOP ( method of procedure) to check HP (hot panels) to be hot and how do we do it?

rlb

[Paul W. Abernathy]

Richard....are you refering to this....


Despite the fact that the person's feet are still contacting ground, any single point in the circuit should be safe to touch. Since there is no complete path (circuit) formed through the person's body from the bottom side of the voltage source to the top, there is no way for a current to be established through the person. However, this could all change with an accidental ground, such as a tree branch touching a power line and providing connection to earth ground:

This might lend one to believe that it's impossible to be shocked by electricity by only touching a single wire. Like the birds, if we're sure to touch only one wire at a time, we'll be safe, right? Unfortunately, this is not correct. Unlike birds, people are usually standing on the ground when they contact a "live" wire. Many times, one side of a power system will be intentionally connected to earth ground, and so the person touching a single wire is actually making contact between two points in the circuit (the wire and earth ground):

The ground symbol is that set of three horizontal bars of decreasing width located at the lower-left of the circuit shown, and also at the foot of the person being shocked. In real life the power system ground consists of some kind of metallic conductor buried deep in the ground for making maximum contact with the earth. That conductor is electrically connected to an appropriate connection point on the circuit with thick wire. The victim's ground connection is through their feet, which are touching the earth.

tehehhe....these little images are soooo COOL......feel like SHOCKIN the little freakin image myself...

[Paul W. Abernathy]

Originally Posted by rbennett

Paul


We are off the time gap of posting -- you say one thing and I say something else and before the other one responds the other one says something that is not relevant to the post

So welcome to the Internet

In short I follow your Ohms law logic

Now back to the HI and the Ele. world

Do we change our MOP ( method of procedure) to check HP (hot panels) to be hot and how do we do it?

rlb

OH.....my bad....sorry I was giving you all the potential theory's and logic and so on........hmmmmm......ahhh...you got me Richard......does NACHI have a MOP.........yeah I am a bad member...I thought HI's only had the SOP...

I will gladly give you my opinions my friend....explain the current MOP for me.....yeah I am a member of NACHI but I have my OWN way of doing things since 1988.....so educate me a little and I will give you my opinion fella...most certainly.

[Richard L. Bennett]

Good morning all

Perhaps a Method of Procedure (MOP) should be written on how to check home electrical systems.

Yes I agree that an electricaly charged panel is possible and checking it before removing it might be a good idea

The proper way of testing it is the question

Is the risk high enough that we should test or is the use of gloves enough protection?

I look at it this way it can test ok before you start to take it off and become energized during removal or reinstalation thus the testing gives you a false idea of safety

One should always assume that it is energized and use the proper equipment to remove same

We do not need a shocking experience to light up our day

rlb

[Greg Bell]

I guess that some people do and some people don't use a ticker to test the cover. I do and just because Richard says you shouldn't doesn't mean that I am going to stop.

I don't have a background as an electrician so I am sure that I take more precautions than someone like yourself. The most dangerous thing I do as an inspector is take off the cover on a live panel. IMHO With that being the case I take as many precautions as possible. I don't remove the cover when my ticker lights up, if it is a Zinsco or FPE brand, if there are pointed screws or if it is humming. I follow those guidelines for my safety. I explain why I didn't remove it in my report and let the client deal with an electrician.

I think it is way beyond our duty to remove an energized panel cover. With that being the case I don't need to learn the proper way to perform such a task.

[Greg Bell]

For me the correct answer is c.

You will have to make your own choice based on your experince.

[Paul W. Abernathy]

lol..well ok I will write a MOP......which will cover any possible issue even the rare situations...

1.) Check the Panel Cover with a non- contact Ticker or the back of your RIGHT hand, or both prior to opening.
2.) Make sure you have safety goggles on ( this one I happen to endorse big time.....long story )
3.) Remove Panel in all cases with caution....as if it were your FIRST time !

4.) Whats it hurt....LIFE is too valuable to waste on a $ 250.00 inspection

Now I think Richard was more just stating issues that are rare but could happen.....and he is quite more experienced than many in the electrical field, hell he probably knows electrical theory better than me.....as myself I don't always follow a so called MOP....BUT I have experience and training that kicks in without trying or thinking about it......

So for the HI I feel better in saying follow the precautions.....stay alert and go with your GUT......amazing enough is the newer panels have the enamal on them...which is not a good conductor..lol...so risks are lower until you go to screw out that energized screw...lol.... but again older panels......worn off enamel or no enamel and whamo...could happen as well....

[gbeaumont]

Originally Posted by gbell

For me the correct answer is c.

You will have to make your own choice based on your experince.

I whole heartedly agree with Greg, there is clearly a problem (found the correct way prior to touching the panel) and the home ispector should attempt no further evaluation of the system until it has been corrected by a licensed contractor.

Greg picture and question Greg.

Regards

Gerry

[Richard L. Bennett]

Shocked

If one wants to test the panel cover and report the results do it correctly

Know how to use your test equipment. Will it give you a voltage indication through the paint on a hot panel cover? Will it give you a false indication when the panel cover is not hot?

Remember not all meters and voltage indicators work the same. If the voltage says it is hot and the owner calls in an electrician and he finds out that it was what you were standing on and not the panel your pocket book and credibility takes a hit.

Take your voltage indicator and see if it will spot a hot panel correctly.

Now how do you find a hot panel cover.

Real simple -- Take the panel cover off your own electrical panel. Make it hot. Test it with your voltage indicator.

Remember that the paint on your panel cover might be different that the paint on your clients cover. Also what you are standing on - the type of shoes that you have on and do you have gloves on etc. will influence the readings on some meters and indicators. Know what makes you test equipment read in error. Know its limits

The test is ok if it makes you feel better but do make sure that your testing methodology is correct.

I still look at all panel doors and covers as hot. Just like all guns are loaded until proven otherwise. Respect Miss Electrical but do not be afraid of her

By the way if you do not test your test equipment on a hot panel door and cover how do you know if it is working??


rlb

[Michael Larson]

Originally Posted by rbennett

Shocked...........

Real simple -- Take the panel cover off your own electrical panel. Make it hot. Test it with your voltage indicator. .........
rlb

You really don't means this do you???? Someone's goonna get hurt or worse. Please, DO NOT DO THIS....

[Richard L. Bennett]

Michael

Thank goodness someone is reading and understanding. One must test the test equipment. If one is not comfortable around a known hot panel cover and how to make it hot should one be inspecting one??

Learn how to use your safety and test equipment

Michael -- how would you get confidence in your self and your equipment?

rlb

[Michael Larson]

Originally Posted by rbennett

Michael

Thank goodness someone is reading and understanding. One must test the test equipment. If one is not comfortable around a known hot panel cover and how to make it hot should one be inspecting one??

Learn how to use your safety and test equipment

Michael -- how would you get confidence in your self and your equipment?

rlb

Richard, I fear there is some misunderstanding here. You did not specify the manner in which you could SAFELY make your own panel hot so you can test your test equipment. I will go back and read th eentire thresad but the post I responded to was incomplete and unsafe in my opinion.

I have been an electronics tech and Engineer for a Standards comliance Test Lab similar to UL. I know how to assure test equipment function and relibility.

[Richard L. Bennett]

Michael

The danger is touching a hot panel cover which is what we are testing for in real life. If one will be exposed to this type of problem in the field and is testing for it one should be able to practice in a safe manor at home.

I wish some others would check in on this thread - many good HEATED questions and comments

MOP to test the test equipment.

Take small 6 ft or so extension cord - cut the socket end off

Find the hot wire with your tester with the cord plugged into a tested GFCI circuit.

Unplug the cord

Skin back enough of the insulation on the hot wire so you can get a good electrical contact to a bare metal point on your removed panel cover. One of the mounting screw holes should be good

Place the panel cover on non conductive surface

Plug the cord back into the GFCI protected circuit

Test with your tester

After testing unplug the cord

Destroy the cord so no one will try to use it

Put panel cover back on panel



--------------------

Test when you are standing on different material with different shoes

I would also contact the test equipment mfg and ask them if testing a panel cover in the manor that we do will give good information with no false positives or negatives.

If your test equipment does not work and you are using it for personal safety you are going to get hurt

I still treat all panel covers as hot with gloves and eye protection

If someone has a better way of testing the tester lets hear it.

BTW if it gives you a positive in the field I would recommend to everyone not to touch the panel cover until the problem is solved.

Just putting it in your report is not the answer. This would be the same as walking into a home an smelling gas.

I was unable to conduct inspection on the inside of the home because when I opened up the front door my test equipment said that there was a high concentration of natural gas in the air. I closed the door and continued with the rest of the outside inspection with binoculars. Recommend that the services of a licensed fire person be obtained

IN SHORT do not leave a major safety issue just for the report. How would you feel if someone got hurt by touching the panel door or cover?

[Paul W. Abernathy]

So basically...follow my posted MOP and be safer.......