GFCI and old two wire power tools?

[larry_g]

In Lumps thread on an old two wire metal cased drill ( http://www.garagejournal.com/forum/showthread.php?t=90709 ) the question came up about adding a three wire grounding cordset. I understand that if the ground wire is terminated on the metal case it will ground the case and add the safety of the modern grounding system. I would think that if you have proper GFCI protected recepticals in the garage as required today that adding the ground wire to an old piece of equipment is unnecessary as the GFCI would detect a short in the tool. What say you trained and educated people?

lg
no neat sig line

 

[sdowney717]

gfci is good as long as it is working. I have had half of my GFCI outlets fail over the years. I suppose that is why the test button.
recently was working in the bathroom with a drill, plugged into gfci. water dripped into the drill and i got a shock.
And the gfci test button works.

 

[nehog]

I always retrofit old tools that came with two conductor cords to three wire for safety. The exception is a tool marked as being double insulated, of course. But the antique tools need grounding, as they get old the leakage current can get high enough to be a hazard, and you can't always be sure you are going to be using a GFCI outlet.

I've also used the GFCI cords from old hair driers for some tools too, when I could not do a proper three wire cord. I've not had the opportunity to test to see if these work absolutely, but I know they will trip from time to time.

 

[plc-landscape]

I' just about to re-wire an old pedestal grinder from the 1930's. If I switch it to 3 wire, where do I ground it? Would I drill a small hole in the pedestal and ground there?

 

[nehog]

I' just about to re-wire an old pedestal grinder from the 1930's. If I switch it to 3 wire, where do I ground it? Would I drill a small hole in the pedestal and ground there?

To the motor, or where the wire enters the unit, or where the switch is. If the wire doesn't go to the pedestal then not there.

 

[Speedy Petey]

I realize the OP is really old but I need to comment.
GFIs do not detect shorts, nor to they prevent shocks. They prevent injury and electrocution.
Also, simply a wet tool will not automatically trip a GFI. Just go to YouTube and watch the videos of hair dryers running under water while plugged into. GFI.
There are a LOT of misconceptions as to what GFIs actually do and how they work.

 

[wyliesdiesels]

I realize the OP is really old but I need to comment.
GFIs do not detect shorts, nor to they prevent shocks. They prevent injury and electrocution.
Also, simply a wet tool will not automatically trip a GFI. Just go to YouTube and watch the videos of hair dryers running under water while plugged into. GFI.
There are a LOT of misconceptions as to what GFIs actually do and how they work.

Good catch. I quickly and hap hazardly read through this thread and didnt really pay attention.

GFCIs will ONLY trip IF there is an imbalance between hot and neutral. U can still get shocked while plugged into a GFCI if the current shocking u returns to the outlet on the neutral side.

 

[marty_p]

GFCIs will ONLY trip IF there is an imbalance between hot and neutral. U can still get shocked while plugged into a GFCI if the current shocking u returns to the outlet on the neutral side.

Great info ~ thanks!