tmbrown97
Senior Member
2 part post...
First - as ano described you can tie all the neutrals together in some situations... one example I saw recently - 2 circuits in a kitchen with common neutral between them. Unfortunately, something happened in this new house - the wire nut came loose where everything was getting tied together - one of the neutrals slipped out. The result was that when the load was too high on one circuit, it caused a power surge on the other. This can basically create up to a 220V circuit depending on the load on the one leg. For my friend that this happened to - as load was increasing on one leg, the other boosted power. She saw the lights inside her fridge get really bright, then heard some popping - and the fridge died. Then an hour later another surge - the electronics on her gas stove fried (120V since gas). Even her microwave went - again; super-bright light, then POP. All gone.
In the end the builder was found responsible and had to pay for the electrician to fix the issue, and they ended up having to buy her all new appliances. I'm probably not giving the best technical description, but when I did some searching on-line I found great explanations of how/why the power got doubled up.
2nd part... I have a very similar situation to what you describe... I haven't done it yet, but my plan has basically been to do what Ano described in post #6. Reuse the wires to get a neutral to the box - then deal with the switching load at the fan, since it'll end up not having a switched circuit where needed - it'll just always be hot.
First - as ano described you can tie all the neutrals together in some situations... one example I saw recently - 2 circuits in a kitchen with common neutral between them. Unfortunately, something happened in this new house - the wire nut came loose where everything was getting tied together - one of the neutrals slipped out. The result was that when the load was too high on one circuit, it caused a power surge on the other. This can basically create up to a 220V circuit depending on the load on the one leg. For my friend that this happened to - as load was increasing on one leg, the other boosted power. She saw the lights inside her fridge get really bright, then heard some popping - and the fridge died. Then an hour later another surge - the electronics on her gas stove fried (120V since gas). Even her microwave went - again; super-bright light, then POP. All gone.
In the end the builder was found responsible and had to pay for the electrician to fix the issue, and they ended up having to buy her all new appliances. I'm probably not giving the best technical description, but when I did some searching on-line I found great explanations of how/why the power got doubled up.
2nd part... I have a very similar situation to what you describe... I haven't done it yet, but my plan has basically been to do what Ano described in post #6. Reuse the wires to get a neutral to the box - then deal with the switching load at the fan, since it'll end up not having a switched circuit where needed - it'll just always be hot.
