2
A local breaker backup relay is used to check the operation of distribution circuit breakers and to trip the feeder circuit breaker if the distribution circuit breaker fails to trip on an overload.
There is a heated bimetallic strip that provides a time delay small overload protection. When its contact makes, it energizes a coil to trip the breaker. Some breakers are mechanical, though. There is a coil that trips the breaker instantly on large overload.
Circuit breakers do not have circuit diagrams. The breakers have an input where the distribution voltage is applied and an output where the load is applied. If you want to know what is inside a breaker, the electrical terminology to use is "shop drawings" of the specific breaker that you need information on.
an interlocking device
If the main breaker has ground fault detection, and the fault is a ground fault, then only the main may trip. Also if the fault is a direct short, the fault current may be several thousand amps, much greater than the trip point of both breakers. Breakers have an I^2T curve (current squared-time), which is an indication of how fast the breaker will trip at a given overload. When both breakers are overloaded, the breaker with the faster I^2T rating at that current level will trip first. This would be an indication that the breakers are improperly specified or adjusted.
2
A local breaker backup relay is used to check the operation of distribution circuit breakers and to trip the feeder circuit breaker if the distribution circuit breaker fails to trip on an overload.
It allows the electrician to organize the distribution of electrical circuits, and holds the circuit breakers firmly in place.
Breakers do not need routine maintenance. If the distribution panel is in an environment that allows dust or dirt to build up on the breaker faces, wipe the breakers with a dry cloth. If the distribution panel has a door on the panel face keep it closed.
There is a heated bimetallic strip that provides a time delay small overload protection. When its contact makes, it energizes a coil to trip the breaker. Some breakers are mechanical, though. There is a coil that trips the breaker instantly on large overload.
The electrical terminology for this type of breaker is a tandem breaker. It is where two breakers circuits can be in the same one breaker slot in a distribution panel. On this type of breaker there will be two output for a circuit value of what ever the breaker is rated for.
No, if you have a Square D distribution panel only Square D breakers will fit in it.
Seeing that you are from Illinois you should know that in North America there are no 10 amp distribution panel breakers.
an interlocking device
Circuit breakers do not have circuit diagrams. The breakers have an input where the distribution voltage is applied and an output where the load is applied. If you want to know what is inside a breaker, the electrical terminology to use is "shop drawings" of the specific breaker that you need information on.
No, each segment of a tandem breaker is what the breaker rating on the handle states. Tandem breakers are used when there is no space left in the distribution panelboard. You get an extra circuit by removing the full size breaker and installing a tandem breaker,
In North America they are known as a GFCI. Ground Fault Circuit Interrupter breaker.