Coppersmith
Senior Member
- Location
- Tampa, FL, USA
- Occupation
- Electrical Contractor
Subtitle: This is why homeowners should not do electrical work.
I was called out to a home where an outside ceiling fan was giving a shock. The leakage was very slight. I could not feel it but the HO who was barefoot and standing on damp concrete said it was tingling. A voltage reading between the fan chain and a nearby receptacle ground read 120 volts.
This place was a mess electrically. I'll give you the highlights. There was a main switch, an outside four slot A/C panel, two inside 100 amp house panels, and a pool panel. Only the pool panel had grounds and neutral separated. The A/C panel was not bonded and had exposed conductors as the insulation had cracked and fell off in places. A voltage reading between the case and a hot read zero.
Now it gets interesting. I flip off all the house and pool panel breakers but the fan keeps running. The fan cable traces back to an outside J-box about six feet away. Opening the J-box reveals eight 15 and 20 amp circuits all connected to the 50 amp feeders for the air handler. No over current protection. AND .... all the neutrals and grounds are tied together.
I assume separating the grounds and neutrals would have solved the objectionable voltage problem, but I didn't do that. Instead I explained the fire danger and then disconnected most of the circuits from the 50 amp feeder. (The HO would not let me disconnect the circuit powering his TV.) I then sold him a job to install a subpanel at that location to make things safe. Apparently, this wiring had been there twenty or so years and was not overloading the 50 amp breaker powering the air handler. We are in discussions about repairing the rest of the electrical mess.
What I find interesting about this is the objectionable voltage "backed up" to the fan instead of flowing back to the panel (source). I guess it was seeking all paths to ground and my barefooted client provided one. What is strange is that the objectionable voltage was never noticed until now (20 years later). Not sure if anything changed.
I was called out to a home where an outside ceiling fan was giving a shock. The leakage was very slight. I could not feel it but the HO who was barefoot and standing on damp concrete said it was tingling. A voltage reading between the fan chain and a nearby receptacle ground read 120 volts.
This place was a mess electrically. I'll give you the highlights. There was a main switch, an outside four slot A/C panel, two inside 100 amp house panels, and a pool panel. Only the pool panel had grounds and neutral separated. The A/C panel was not bonded and had exposed conductors as the insulation had cracked and fell off in places. A voltage reading between the case and a hot read zero.
Now it gets interesting. I flip off all the house and pool panel breakers but the fan keeps running. The fan cable traces back to an outside J-box about six feet away. Opening the J-box reveals eight 15 and 20 amp circuits all connected to the 50 amp feeders for the air handler. No over current protection. AND .... all the neutrals and grounds are tied together.
I assume separating the grounds and neutrals would have solved the objectionable voltage problem, but I didn't do that. Instead I explained the fire danger and then disconnected most of the circuits from the 50 amp feeder. (The HO would not let me disconnect the circuit powering his TV.) I then sold him a job to install a subpanel at that location to make things safe. Apparently, this wiring had been there twenty or so years and was not overloading the 50 amp breaker powering the air handler. We are in discussions about repairing the rest of the electrical mess.
What I find interesting about this is the objectionable voltage "backed up" to the fan instead of flowing back to the panel (source). I guess it was seeking all paths to ground and my barefooted client provided one. What is strange is that the objectionable voltage was never noticed until now (20 years later). Not sure if anything changed.
