Two Prong Plug

[safe]

If a two prong plug (one prong is polarized) is plugged into a three prong receptacle is the appliance with the two prong plug "grounded"? I have a metal box fan with a flat two-wire cord with a two prong plug. When I take a volt pen and touch the cord in several places the volt pen has a steady glow. When I touch the metal part of the fan with the volt pen it does not glow. Now when i turn the fan on and touch the metal part with the volt pen it glows steady. This tells me the fan is not grounded. Is this correct. Should the fan be disposed of?

 

[boo1]

The two prong plug has a hot and a return leg, no neutral of ground. Commonly they are insulated cases.

 

[ERaySir]

It must be an older fan. Most apliances that utilize a two prong plug have no exposed metal pieces hence no chance of shocking the user. The older fan case should not have an electrical connection to either of the two prongs. This can be checked with a continuity meter. If it does either the motor has a ground or the cord is split somewhere and the conductor is in contact with the housing or case. The cord can be replaced with a three wire cord by attaching the green conductor to the housing or case (assuming you live in North America). If the motor is faulty, it is usually not worth repairing.


Best Regards

Ray Micallef, P. Eng.
Power Generation/Utility Industry

 

[boo1]

It the case is metal you can do as as indicted above. If it has a Plastic case it is probably double insulated.

 

[ietech]

Hi Safe,

If your "Glow Pen" is like all that I have ever used it is very inaccurate in picking up accutate indications of voltage or amps. It will pick up all kinds of stray voltage including static. Would never use it to detect elect if my life depended on it. Good for continuity i.e. chek fuses, some types of light bulbs, conductor integrity etc.

If you are terribly concerned get a multimeter set it for volts AC and check for actual voltage. If it is an older fan I would re-wire and attach a ground or better yet get a new fan --- not very expensive and it would resolve your issue with the one you have.

Good Luck

ietech

 

[chicopee]

TWO PRONG PLUGS ARE NOT GROUNDED, PERIOD.

 

[ietech]

Chicopee

You are correct, I think that is the reason for the original post.

This is simply resolved by adding a three wire cord and three prong plug, then grounding the fan chassis to the ground wire.---- OR buy a safe fan.

If "Safe" has polorized plug on his fan it is most likely a double insulated unit and does not require a ground.

His test equipment "Glow Pen" is questionable also. Most of these types will show voltage if you touch it with your finger or even static in the air.