Bill in Georgia

AFCI breakers test for Ground Faults also. They test for ground faults above 30 milliamps whereas GFCIs test for ground faults between 4-6 milliamps.

Three phase power is more economical for motors than single phase. I wish I had it for my A/C. Lots of homes in Albany, Ga have three phase for their A/Cs. Some are in single phase panels with a three phase style breaker which has an input for the third leg and outputs for all three phases. I put a label in these types of panels that this breaker and the main breaker need to be turned off to remove all power from the building.

225.22 says that raceways in wet locations shall be arranged to drain, which this circuit obviously is not. Also, if the pipe contains a feeder circuit or a branch circuit, there must be a disconnecting means near the point of entrance. Feeder circuits also require grounding to earth.

This is a loose connection in the wirenut area. Both wires and the entire length of both wires had the same amount of current flowing through them but only the wirenut area experience extreme heat. This could have been through a very small (high resistance) connection or a totally open connection where arcing took place. Arcing gets very hot (like welding). As the voltage swing peaks at 120 and then again at -120 (actually +198 volts and -198 volts) it looks like it was high enough to jump the gap in this case. The higher the voltage, the further it will jump.

Romex and UF cable must have their outer jacket to extend into nonmetallic boxes at least 1/4" beyond any cable clamps. No code suggests the maximum distance that the outer jacket can enter into a non metallic box and there are no codes for minimum or maximum outer jacket lengths for metal boxes. NEC 314.17. No such codes exist for panels. However, 310.10 requires that conductors cannot be associated together where the limiting temperature of any of the conductors is exceeded.

The 2005 NEC allowed receptacles in garages that were dedicated or inaccessible to be excluded from the GFCI requirement for garage receptacles. That exclusion was removed. Now all receptacles in garages must be GFCI protected.

Arc fault detection is primarily a parallel fault type of detection today. This can happen when the insulation is deteriorated such as with old wiring in old homes. The promise of combination type arc fault detection is that it will also detect low current series type faults (loose connections). This type of fault can happen even in new wiring. If older homes have breaker panels that will accept AFCI breakers, they seem to have the best use to gain from them. Also, GFCI breakers detect ground faults between .004-.006 amps. Regular AFCI breakers detect ground faults above .030 amps. AFCI/GFCI breakers detect ground faults between .004-006 amps. Therefore, all AFCI style breakers will trip if the neutral and equipment ground are touching anywhere on the circuit.

I hope there are no kids or even adults nearby. Just touching the screwdriver could kill someone. This sander must pull quite a bit of current judging by the arc damage on the screwdriver. I wonder if they turn both of the breakers off before making connections. One breaker looks like the main breaker for the panel. What about back feed. Take one screwdriver out and it is probably still energized. Unbelievable!

NEC Table 300.5 gives the following cover requirements: Burial Depth is 24" in yard if in cable 18" in yard if in PVC conduit 18" if under 2" in concrete in cable or PVC conduit If cable is buried, it must be protected in conduit down to a depth of 18"

You might get the power company to check your neutral connections. If the neutral gets loose at the transformer, weatherhead, meterbase or service disconnect switch then you can get high voltages throughout the home. These high voltages will smoke a GFCI receptacle or breaker. If you have a volt meter and know how to use it without getting electrocuted, you can check the voltages in your main panel. If you have a loose neutral, then if the voltage drops on one hot leg by 20 volts, then it will go up 20 volts on the other hot leg. So if you have say 100 volts on one leg to ground and 140 volts on the other hot leg to ground, then you have a loose neutral somewhere. The utility provider will check their lines at no cost.