In this instance I am building another crank-lamp. So, big metal object, sitting on the floor, or a desk. Do I wire it up with a 3-prong cord and ground one to the "chassis"?
In this instance I am building another crank-lamp. So, big metal object, sitting on the floor, or a desk. Do I wire it up with a 3-prong cord and ground one to the "chassis"?
Always use a ground.
How are you going about it making it?
I would have thought the easiest option is to take an existing lamp and take the lamp parts and put them on the crank and whatever cord it has is what remains
If an appliance has exposed metal structure, it should be grounded.
In reply to Kenny_McCormic:
No desk lamp I have ever owned had a 3-prong plug, despite being almost entirely metal.
If it is not double insulated, it should be grounded.
Double insulation. Some appliances, such as vacuum cleaners and electric drills, do not have an earth wire. This is because they have plastic casings, or they have been designed so that the live wire can not touch the casing. As a result, the casing cannot give an electric shock, even if the wires inside become loose.
If there is any way a hot wire could touch the metal and energize it, it needs to be grounded.
Duke wrote: In reply to Kenny_McCormic: No desk lamp I have ever owned had a 3-prong plug, despite being almost entirely metal.
Then they're "double insulated", old, or cheap IEC Class 0 stuff that's illegal in a lot of the 220v world. In any event it can't hurt to ground it, it can hurt to not ground it, or worse yet do some stupid well meaning thing like connecting the neutral to the chassis in lieu of a ground wire.
Electrical products will typically have 2 means of protection to prevent the user from getting shocked.
These are typically:
One layer of basic insulation and a safety(chassis) ground
two layers of basic insulation
one layer of reinforced insulation (equivalent to 2 layers of insulation, ie "double insulated")
The intent is that in a single fault condition, where one protective means fails, the user is still protected.
Insulation can be a physical barrier or the appropriate spacing between live wires and conductive materials.
Double insulation is prefered since grounding exposed metal provides a path to ground that can result in electric shock if the person touches a "live" wire/surface and the grounded metal.
fritzsch wrote: How are you going about it making it? I would have thought the easiest option is to take an existing lamp and take the lamp parts and put them on the crank and whatever cord it has is what remains
Weld 1/8" pipe fitting to end of crank, connect bulb socket, run cord, attach shade.
Duke wrote: In reply to Kenny_McCormic: No desk lamp I have ever owned had a 3-prong plug, despite being almost entirely metal.
This is my experience. I've made a few of these, and always used a "lamp kit", which has never provided a ground. I've never seen a ground on any lights unless they are ceiling mounted.
Anyway, no problem for me to add one. I just drill & tap somewhere on the metal surface to connect the green wire?
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