Originally Posted by jimmie
, and am investigating the circuitry, just so I know.

Hi jimmie,

Probably no need to check circuitry.

Most electric circuits are 20 amp circuits. Sandeep mentioned 15 amp, in the "modern era" lighting only circuits may be 15 amps, but most "receptacle" circuits are 20 amp.

There are two potential concerns. One is overloading the circuit. This usually can be explained in 2 words: Space heater. Or toaster. Or hair dryer. The devices that use the most electricity are those that generate heat. Classic scenario: Circuit breaker trips in December. Anything different? No....well....maybe the space heater under my desk that I didn't tell you about....In this instance, the loads must be distributed, so a single circuit does not have more than a 20 amp load on it.

Note that a breaker will trip at a continuous load of over 20 amps. A momentary load, like a motor starting. may involve very high current flow, but should not trip the breaker.

The second involves voltage drop. This is involved in the "lights dimming" phenomenon mentioned earlier. A heavy load (air conditioner or heat pump starting) will momentarily pull A LOT of current. This effect is more pronounced if it is on the same circuit as the device you are concerned about. This is especially pronounced if there is a very long distance from the circuit breaker panel to the load, or if the circuit is heavily loaded with other devices.

If you notice a problem when printers/air conditioners/etc start, then you might look at which receptacle is on which circuit, and even have to run a new circuit or two. The huge majority of the time, unless the breaker trips, no problem.

A UPS is very helpful in this situation. Typically the UPS will monitor input voltage. If in an acceptable range (often 105-135 volts) it will let the device run on AC power. If the input power goes outside of this range, then AC is disconnected, and the device runs on battery, just as if there were a blackout.

Gene


Gene Nallin MD solo family practice with one PA Cumberland, Md