Updating the electrical in a house
If this happens with a grounded tool, a short circuit is created, and the breaker trips.These days, not many tools, lamps, or appliances have three-pin plugs.The insulation on a wire inside the drill could become damaged.If that live wire touched the metal case, the tool could be energized to 120v, and that’s not good.The downside is that it’s hard to tell exactly what downstream is in a 60-year-old house. I wouldn’t worry about grounding the branch circuit for grounding’s sake.I’m not saying that you shouldn’t ground every outlet, just that the cost is high and the benefit low.Many older homes were built with 60 to 100 amps of electrical service.
The idea is that if there’s a difference between what’s going out and what’s coming back in, that difference in current might just be leaking out through a person.It can be difficult and very expensive to replace parts and make repairs to obsolete panels.Of more concern is that some brands of obsolete electrical panels such as Zinsco and Federal Pacific can actually be a dangerous fire hazard.Common warning signs that your electric service is overloaded are brownouts, or lights dimming when you turn something on. If you know your electric service is underpowered and you don’t trip circuits, that can also be a cause for concern.
A circuit that trips is doing it’s job to protect your wires from overloads and overheating.
Rather than running a separate grounding conductor all the way back to the panel, you could use a ground-fault circuit interrupter, or GFCI (also referred to as a GFI).