We tried to replace a wall heater yesterday (240 volts on a 20 amp double breaker). It was supposed to be a very straight forward job but we ended up with an electrical problem with the wiring.
This is in common area of a condo complex. There are 7 meters in the basement. One breaker panel for common area. Then each unit has a panel inside the unit which we don't have convenient access to.
1. Initially: black to red at heater around 240.
2. Turn off breaker.
3. Black to ground 0. Red to ground 120.
4. OP attempted to replace with the hot red wire (mistake) and shorted wire to ground
5. Half a second spark. Red went to 0. No breaker flipped on common area panel.
Now the red is at 0. Breaker has 240 volts at the red and black coming out at the breaker on the panel. But that red did not turn off when we turned the breaker off while the black did!
One possibility is that the red comes out of one of the units and flipped some breaker in the unit adjacent to the heater. But then I have a black on one meter and a red on another! Is this possible?
What else could be the problem? We did not smell anything nor we saw any melted wires at either end where the red is visible. Could the red wire have melted somewhere in between the panel and the heater? Can a half a second spark cause this?
Thanks much!
This is in common area of a condo complex. There are 7 meters in the basement. One breaker panel for common area. Then each unit has a panel inside the unit which we don't have convenient access to.
1. Initially: black to red at heater around 240.
2. Turn off breaker.
3. Black to ground 0. Red to ground 120.
4. OP attempted to replace with the hot red wire (mistake) and shorted wire to ground
5. Half a second spark. Red went to 0. No breaker flipped on common area panel.
Now the red is at 0. Breaker has 240 volts at the red and black coming out at the breaker on the panel. But that red did not turn off when we turned the breaker off while the black did!
One possibility is that the red comes out of one of the units and flipped some breaker in the unit adjacent to the heater. But then I have a black on one meter and a red on another! Is this possible?
What else could be the problem? We did not smell anything nor we saw any melted wires at either end where the red is visible. Could the red wire have melted somewhere in between the panel and the heater? Can a half a second spark cause this?
Thanks much!