Mike Holt’s blog is a fantastic resource for information. More Inspectors should make it a regular read. The reason for the development was to protect people from electrical shock.
I saw a video a while ago that poked fun, in an educational way, at the GFCI. It went something like this…how many times when a GFCI trips, do you phone around to your friends and say, I’m having a party to celebrate the GFCI that saved my life? Then think how many times you’ve cursed a GFCI because it tripped ad you blamed it for not being able to complete what you were doing?
Knowing of a risk, and then properly classifying it should be part of our care of duty. Exaggerating risks because we don’t understand the principles behind the fundamentals we’ve learned is not.
Any electrical shock is a risk. How many Inspectors get static shocks from homes and then warn their clients that the home is potentially hazardous to them if they have a pacemaker fitted? (Hopefully, the answer comes back ‘nil’)
If you told someone without a pacemaker this, their mind immediately goes to the fact that the house has an electrical fault.
The same thing with this thread.
Sure you can identify the risk that if you come across an ungrounded GFCI, and you test it (against all recommendations) with a 3-light receptacle tested with GFCI button, and it has a metal front, and you are kneeling on damp ground, the 6mA shock you might get for the time you press the button, it might kill you.
But really!!! If you travel to the USA and you choose to go to a bank that is being robbed by armed gunpersons and you choose to ignore their demands to get down on the ground, that might kill you too. I don’t see anyone posting threads about that, and I suspect given the current gun crime in the U.S. (another thread please) the risks would be much higher.
Th real lesson to be learned here is don’t use a night-light (aka a 3-light receptacle tester) which are notoriously inaccurate at identifying defects anyway, to test a GFCI. Use the manufacturers recommended test method. The test button on the receptacle.
This must have been said thousands of times on this and other Inspection threads, but the situation keeps coming up and keeps generating reams of comments about the effects.
Part of being a professional is using the right tool for the job.
A 3-light tester is a quick and dirty method for rapidly identifying some very simple cases where wiring might be incorrect. They are not infallible, they fail to detect many dangerous defects.
Do I use one? Yes
Do I also use other equipment to back up my concerns? Absolutely.
Do I use them for testing GFCI’s? Absolutely not.
and although Mike Holt’s blog is great as a learning tool, sometimes a picture tells a thousand words, so here’s one for you.
https://www.physics.ohio-state.edu/~p616/safety/fatal_current.gif
The original paper from the physics department at OHIO State University can be read here.