I have a 3 pronged device, and need to use a 2 pronged outlet. I have an adapter, but it advises that I connect the metal tab to a "ground screw." Is it alrignt if I do not do this, and if it isnt, what do I have to do?
Its more of an electrical safety requirement. It just ensures that there is an alternate path back to ground (besides your body) in case the neutral wire is broken or cut. Some things like UPSes do need the ground though.
If the electrical box that houses the outlet you want to use is metal then you should be able attatch the grounding tab of your adapter to either the top or bottom screw that hold the plastic faceplate to the wall provided that they screw into the metal tabs of the plug or the box itself and you ensure that there's bare metal on the underneath of the screw head where your tab will contact them. If the electrical box is properly grounded and you have metal to metal contact from the grounding tab to the box (via the screw) you should be set. All you need to do is remove the faceplate and visually ensure the box is metal, no poking around inside! If the device has three prongs it's best to give it a ground. I'm a construction electrician by trade btw Hey Xian, I installed a UPS room at a facility where they actually "grew" the silicon to be ground into wafers and the room was wall to wall car batteries all hooked in series (yours truly got to haul in and install all those batteries). Pretty cool stuff to see on such a large scale
That many batteries in series - or do you mean in parrallel? (series adds voltage parrallel adds current supply ability)... so do you do the tongue test to see if they are flat? I wonder what that sort of current would do to a moist tongue... BTW - before even thinking about using the adaptor - please ensure that the device is capable of handling the voltage supplied by your outlet... and not an imported device i.e. a 240V 50Hz device on a 110V 60Hz outlet...
