While I was testing a power outlet, the live wire side of the outlet touched the metal boxing and some sparks flew and knocked out the power for the entire house. Both the breaker for the outlet and the main breaker were tripped. After resetting both the breakers I got the power back up.
I would like to know if that could of caused any potential damage to the electronics in the house that are on different circuit breakers in the breaker panel. All the rooms in my house have properly grounded outlets except for one I just discovered where the grounding wasn't working properly. That one room has two desktop computers, computer networking equipment that are all plugged into a surge protector. So far all my electronics turn on fine. Since the room isn't grounded properly I am concerned if outlet accident would have caused any damage to the equipment in that room. I have no electrical background so if any certified electrician could answer my questions I would greatly appreciate it.
Over/under voltage situation and the power cutting on/off rapidly are the things most damaging to electronic circuits. If you computer's hard drive happened to be writing at the point the power was cut, then you might experience some data corruption but it shouldn't be catastrophic. If the equipment is working, I wouldn't worry about it.
Actually the computers were off at the time but the modem, router and switch are on 24/7. Not sure being powered off makes a difference as they are connected to the outlets through a power surge protector however the room they are in have outlets where the grounding that isn't working.
I turned off the power and checked the wiring in the room with malfunctioning grounding, the outlets have the ground wires connected tightly and the ground cable is connected at the breaker panel end as well. I have no idea why it stopped working.
My concern at this point is that you have a room full of electronic equipment that has no ground. Without a good ground, a surge protector cannot operate properly. If it is just that room, then you should be able to follow the circuit that supplies that room to the next junction box/outlet/switch outside that room leading back to the breaker box. Somewhere along the line ground continuity was lost, and it should be a simple matter to fix.
By the way, an easy method to keep outlet screws and wires from touching metal electrical boxes is to wrap electrical tape around the outlet once the wires have been installed.
I have the power surge bar plugged into another room with working grounding via power extension cord after I found out the grounding stopped working. It was actually the screws on the right side of the outlet that touched the metal boxing while I was checking how the wiring looked on a grounded outlet. As for the room with no working grounding, I can only check the outlet itself and the ground wire connection to the breaker panel itself, they are all connected tightly, I am unable trace the whole power wiring completely as they are behind dry wall. To me it seems rather odd that I get perfect power to the outlets and since the ground wire is in the middle of the power cables, so something damaging only the ground wire in the power cabling is unlikely.
Is there anyway to test if the ground wire is working from the breaker panel end to the outlets? If the hot and neutral wires were reversed would that cause the grounding to stop working?
If you have a bad ground only at the outlet(s) in one room, then it is reasonable to assume the room is at the end of a circuit. Cut power at the breaker panel to that room, and look for other outlets and lights that also do not work. These items will be ahead of your bad ground in the circuit. Starting at the nearest physical location to your bad ground, remove the cover plate and switch/outlet. There should be a ground both coming and going at that point. You are correct that having a ground wire go bad in the middle of a cable is almost unheard of. It is the continuity of connections that is missing here.
I am not sure how you are testing your outlets for ground, but a simple outlet tester like the one shown below will indicate good or bad grounds, as well as reversed polarity. The effect of reversing hot and neutral wires can vary from sparks flying and breakers tripping to nothing noticeable at all, depending on where it is done and what else is connected. This will not impact grounding though. If you find reversed polarity by all means fix it asap.
I have been testing my outlet grounding by plugging in a new surge protector I just bought, it has a led that turns green if the grounding is working. I have used it in all my other rooms and it shows working grounding and an older surge protector I have been using also says the same thing.
The room has 5 outlets and none of them have working grounding and all 5 outlets are on one circuit with nothing else connected to it, the wiring of the circuit goes directly to the breaker panel. The lighting in that room is on a separate circuit which has working grounding. I have checked all 5 outlets and made sure the grounding cable is connected properly to the ground connector on each outlet. If reversed polarity doesn't effect grounding then I have no idea what's causing it at this point.
I tried searching for an outlet tester on the Canadian Home Depot website but I am unable to find any.
I figured out why the surge protector was displaying no ground for my outlets. The contractor that finished that room a few weeks ago apparently reversed the hot and neutral wires in the original outlet while adding the additional 4 outlets. After correcting the wires in the original outlet, all of them are working fine now, I bought an outlet tester from my local hardware store and tested all the outlets just in case.