electricalreceptacle
I am replacing some receptacles that are contained within metal electrical boxes in my shop.
Is it proper technique to wrap the outlet with electrical tape to prevent shorts with the grounded box (See New receptacle tripped/sparked for example)?
If wrapping the outlet is correct, does it need to be de-rated due to the potential higher temperature caused by the insulation effect of the tape?
There's a many different ways to do it, and how it's done depends on personal preference.
In this variation, the Electrician will leave one of the grounding conductors long. He'll install a ground screw in the threaded hole in the back of the box, and loop the long conductor around the screw around the middle of the conductor. Then he'll collect all the grounding conductors in the box, and twist them together with the remainder of the long grounding conductor. Once twisted, he'll use either a crimp or twist-on wire connector to "permanently" connect the conductors together.
Another option is to gather all the grounding conductors together, and twist them together with an extra bit of grounding conductor. Again using a crimp or twist-on wire connector to "permanently" connect the conductors together. Then connect one end of the extra bit of conductor to the box using a grounding screw, or a grounding clip.
More recently, guys have been using Greenies from Ideal industries. They're basically a twist-on wire connector with a hole in the top. This method is similar to the long tail method, except that the long tail feeds through the Greenie, and the remaining grounding conductors are connected to the long tail using the Greenie as a twist-on wire connector. The bit of wire protruding from the end of the Greenie is then wrapped around the ground screw, or attached to the box using a ground clamp
I was able to figure it out. Apparently the dimmer switch ended up being the culprit. It must have shorted out when the wire sparked last night.
Best Answer
If the box is grounded, there isn't a reason for wrapping tape around the box unless the receptacle is loose, and you have movement of the receptacle. This would be a poor way to correct the problem, because the tape on the box may come loose over time because of dampness in a workshop. The optimal approach would be, to use oversized screws to correct this. I would also use a metal box cover for the metal box.
Furthermore you may want to see if one of the outlets ARE GFCI protected type. You may or may not have water in your shop, but usually there can be a lot of dampness present in a shop. If one of the receptacles isn't GFCI then you may want to purchase a GFCI breaker for your box, and replace the breaker that powers your outlets. You could also use a GFCI receptacle for the GFCI (Ground Fault Circuit Interrupt), but it is normally limited to the number of receptacles depending on your local codes. Good luck!