I was trying to locate the circuit breaker for an outlet in my garage and found a truly baffling setup. Two breakers control the same outlet (both plugs). After some head scratching, I opened the breaker box and found (see pic) breaker 4 (20 amp) wired to the outlet as expected but breaker 34 (30 amp) wired to breaker 4. Why would this be done? It was obviously intentional and possibly setup for a freezer. Is this safe and in anyway an accepted practice?
Thanks everyone for the help! I know enough to keep from getting electrocuted and this just didn't meet the logic test. I'll be checking the wiring and hopefully this is the only work they attempted.
Best Answer
As @Ecnerwall says, definitely not safe / legal / advisable.
My guess is that the guy kept tripping breaker #4 (maybe too many power tools in the garage?) and decided to share the load with another breaker by adding the extra wire. Approximately half of the current will flow through each breaker, effectively creating a 40 amp breaker.
EDIT: in fact it's possible / likely that the wires on that circuit were regularly carrying more than 20 amps. Wherever possible you should inspect the wiring, including all outlets on that circuit, to see if there are any signs of melted insulation or other damage. If you find any indication of heat damage I think it would be prudent to rip out the entire circuit and rewire it, since there may be damaged insulation in the walls just waiting to catch fire.