Originally Posted by jhack836
one quick guestion. you guys say for the breaker to trip i need it to be grounded. how did things work back in the day or even some houses today that arent properly grounded? the home owner just taking a risk?>
That's very close to correct. But what is existing cannot readily be changed. However when things are added and wiring changes made to ungrounded wiring you, in most cases, must bring these changes up to current code standards. Nothing is perfect and completely safe. Over time electrical systems have undergone improved safety for design and installations. After all that really is what the NEC is written for .... a book of code that sets forth the standards for minimum safety requirements in electrical installations.
Electrocutions of humans in single family homes was quite alarming in the older un-grounded wiring design. Then the code making panels (CMP's) required the equipment ground wire, then gfci came along in the 80's, then in 1996 they did away with bonding neutral and ground for range and dryer 3 wire 120/240 volt circuits and electrocutions have fallen dramatically. Over the past 3 code cycles AFCI has taken the forefront for safety improvements. These are protecting property and loss of human life from fire by tripping out afci breakers when parallel or series arcing occurs in the wiring, thereby preventing a fire. So its been an ever evolving process to improve human safety and property protection.