An open panel door allows you to access all the fuses or circuit breakers inside the panel. Usually, a single panel is able to feed the entire house. Nevertheless, there are instances wherein another sub-panel is used to cover a particular area or an additional room.
These breakers are stacked inside the panel and are operated using a lever that switches it ON or OFF. Aside from this, a large double-pole type of circuit breaker can also be seen on the "main" portion of the panel. This is the one that controls all the power to the different circuit breakers below.
Most of the time, there are stickers placed to every breaker to determine the circuit that is served by a specific breaker. In other conditions, a sheet is attached inside the panel door that provides enough space to identify the circuit.
If the service panel consists of a fuse box, a number of screws are typically used in replacement to the circuit breakers. Nonetheless, the function of the panel is still the same.
The electrical service panel cover is usually attached with four screws, one in every corner. Once these screws are detached, you can already get access to the components of the said panel. However, this is usually done when you are only adding a circuit.
The power is produced directly from the power line of the electric company. This is delivered through the electrical meter seen outside your house. The main circuit breaker is usually known as the Double Pole Service Disconnect. This is the one that operates the live power in energizing all the circuits in the panel. This can be easily recognized due to its thick black wired that feeds it from the electrical meter. Aside from this, it also consists of two handles that are joined together. The primary or Main circuit breaker is utilized to power all the other circuits at one time.
In addition to this, the Main is also able to identify the amperage capacity of the panel. This amp capacity will be measured in number such as 150 and 100. A 100 amp size is considered to be the minimum code that is allowed nowadays. However, the 150 amp service is recognized as the most common. Other amp sizes available for panels are 400 amp and 200 amp.
Upgrading your electrical panel isn't a task a homeowner would typically do on their own, which is why every city has it's share of professionals to handle the job.