I have an small external shed that I use for some minor work every now and then, basically just some grinding and cutting, sometimes a little bit of welding. It is fed from the main breaker panel at the house with 3 wires to a fuse box in the shed. A couple of the fuses are blown and the sockets for the fuses are damaged. A metal water pipe runs from the house to the shed and in both locations are close to the panels and connected to the panel grounds In the shed, there is no separate ground/neutral. I'm just planning right now but wanted to know if the following would be safe and up to code without having to dig a trench up and run any new wiring.
With only a 3 wire feed I don't think I can have have a separate ground/neutral in the shed using only those wires. Is it safe and allowed to use the metal pipe between the home and shed as the grounding conductor and then the 3-wire feed as just the hots and neutral? I would essentially replace the damaged fuse box with a breaker panel, connect the 3 wires to the hots and neutral accordingly, replace the copper wire and grounding clamps from the pipes and run it to the grounding terminal in the new breaker box leaving the neutral/ground bonding screw removed. In addition I'd install a grounding rod or two and connect them to the ground of the new breaker box.
With only a 3 wire feed I don't think I can have have a separate ground/neutral in the shed using only those wires. Is it safe and allowed to use the metal pipe between the home and shed as the grounding conductor and then the 3-wire feed as just the hots and neutral? I would essentially replace the damaged fuse box with a breaker panel, connect the 3 wires to the hots and neutral accordingly, replace the copper wire and grounding clamps from the pipes and run it to the grounding terminal in the new breaker box leaving the neutral/ground bonding screw removed. In addition I'd install a grounding rod or two and connect them to the ground of the new breaker box.
