suemarkp
February 19th, 2004, 02:24 PM
What are you grounding, your electrical service or old individual electrical outlets? It sounds like you're doing the second case, in which case both solutions you presented are wrong.
Lets take the easier case first. If grounding a service panel, it needs to go to two ground rods at least 6' apart and must also connect to your metal water piping. If this metal water pipe comes into the house from a metal pipe buried in the ground, then it needs to have the ground wire attached within 5' of where the pipe enters the house. If the buried pipe outside is 100% plastic, then you connect the ground wire to the metal pipe anywhere that is accessible on that pipe.
Second case. If you're trying to ground old ungrounded receptacles, the only legal way now is to run an individual wire from that receptacle all the way back to the service panel (where you probably won't have enough holes to terminate all these new grounding wires). You never want to ground a circuit by connecting to a rod or pipe! This is a major pain, and you can spend 10% more effort and pull new and better cable to replace the old wires there. An alternative is to leave them ungrounded, but protect the receptacles with GFCI receptacles or breakers. The first receptacle on a string can be a GFCI and it will protect all downstream outlets. However, there could be some implementation issues with this in an older house, especially if wires have been crossed or shared somewhere.
In both cases, the size of the wire used matters. For the first case we need to know the size of your service in amps (100, 150, 200, etc). For the second case, the ground wire size depends on the size breaker or fuse protecting that circuit.
Lets take the easier case first. If grounding a service panel, it needs to go to two ground rods at least 6' apart and must also connect to your metal water piping. If this metal water pipe comes into the house from a metal pipe buried in the ground, then it needs to have the ground wire attached within 5' of where the pipe enters the house. If the buried pipe outside is 100% plastic, then you connect the ground wire to the metal pipe anywhere that is accessible on that pipe.
Second case. If you're trying to ground old ungrounded receptacles, the only legal way now is to run an individual wire from that receptacle all the way back to the service panel (where you probably won't have enough holes to terminate all these new grounding wires). You never want to ground a circuit by connecting to a rod or pipe! This is a major pain, and you can spend 10% more effort and pull new and better cable to replace the old wires there. An alternative is to leave them ungrounded, but protect the receptacles with GFCI receptacles or breakers. The first receptacle on a string can be a GFCI and it will protect all downstream outlets. However, there could be some implementation issues with this in an older house, especially if wires have been crossed or shared somewhere.
In both cases, the size of the wire used matters. For the first case we need to know the size of your service in amps (100, 150, 200, etc). For the second case, the ground wire size depends on the size breaker or fuse protecting that circuit.
