Electrical panels/Panel boards are metal boxes with circuit breakers, fuses, and the main power switch for the whole house, helping to give out power across the house while keeping it safe and stop electrical malfunctions/fires. They make it easy to shut off power for certain places, like in renovation, repair work. It's a gray metal box with a door.
high voltage wires
[2] The power running our appliances is often at a power plant. Going long ways through high voltage wires (tall towers disturbing many's views) through a transformer at a substation that steps down the voltage and then through another local transformer, one of those big “cans” you may see on telephone poles along the road, where it steps down again. Finally, the electricity passes through the power lines to the meter at your home and into the breaker panel. The voltage that could be measured in the thousands at the beginning of its journey is rated at 120V or 240V at your panel—just the right amount to keep your home running.
[2], [3] Fig 1 shows a basic breaker panel's schematic in pst basementss/utility closets/garages.
The main circuit breaker is often at the top shutting off a whole home’s entire power supply. The meter's power feeds into the main breaker and hot wires (with AC current flowing in green as shown by Fig 2) connects to it. Main breaker can be manually moved to cut the power to everything of the main breaker.
It also gives overcurrent protection to the property, tripping often at ~100 or 200 A.
[3] 2 main bus bar connect to main breaker, exposed metal sheets carrying AC current to the breaker. They're live/hot.
Under the main breaker are 2 vertical branch breakers feeding into parts of a home. It may say “Dining Room,” “Kitchen Lights” “Master Bedroom," etc. Appliances using lots of energy, like HVAC systems/electric stoves, may have their own breaker.
[2] Fig 1
Fig 4
Service cable SEU (Service Entrance Unarmored) is a type of cable bringing power from an utility to a building's main electrical panel, often typically flat and often used as panel feeders, especially in multi-family dwellings and for branch circuits.
Neutal bus bar: When power leaves the panel in hot wire of a circuit and works through the devices (light bulbs, outlets, etc.), current returns back to the service panel in the neutral (often white) circuit wire, connected to the neutral bus bar, which connects to the main service neutral and returns current back to electric utility grid.
Neutral bus bar (for white wires) are either on left/right side near the main breaker/service disconnect, maybe labeled "Neutral/N".
Note: In subpanels, neutral and ground must be separate.
Hot bus bars (for black/red wires)
Ground bus bar (for bare/green wires), in main panels, are the same as the neutral bar (if bonded). In subpanels, are separate bars, sometimes at the bottom/side.
[3] Fig 2
[3] Fig 3
The neutral and ground bus bar are metal strips with screws and holes.
As it has a main panel, the 2 bus bars can be joined by a connector bar of neutral /ground connection.
Note: Subpanel must have separated bars.
There maybe a green screw bonding the neutral bar to service panel's the metal casing.
The neutral bar's goal is
return electricity back to the transformer.
The 2 hot wires give
electricity. When used, it returns to the transformer via its
neutral bar.
Note: It's still AC current the gif only shows current going in 1 direction to see the taken path.
Using a multimeter at the lead to the bus bar and the other lead to the neutral bar, it says
~120 V
If we connect it meter to the
leads to the 2 bus bars, it says double--240 V.
To understand how this works, look at how a transformer connects in a main panel: 2 bus bars connect to either secondary coil's end, then we take the neutral bus bar connected to the secondary coil's center.
Therefore, connecting the across the bus bar and the neutral bar, we only use half the coil--only getting half voltage the transformer gives.
If we connect to the 2 bus bars, we connect to the coil's full length so we get the full voltage the transformer gives--240 volts.
Circuit breakers control electricity flow into each circuits, manually tripped to cut power.
It has 2 crucial purposes:
Overload protection if too many
things are plugged in, current is above the the breaker handles and trips to cut power
off the circuit.
Short circuit protection if the hot and neutral is direct contact with each other. The current increase almost instantly if this occurs. It makes a magnetic field which trips the breaker and cut power.
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Difference with fuse panels
[4] Model numbers are alphanumeric codes uniquely identifying products in catalog, used by manufacturers.
E.g. The Model # CPL104 means:
CPL may mean a product series, maybe meaning like "circuit panel."
104 often indicates a specific model in the "CPL" series or the panel's size, circuits number or other specific features like voltage/amperage/configuration.
CCPL: This could be a variant of the "CPL" series, where "CCPL" might indicate a specific configuration, such as a "commercial" version or a "combination" panel. The "CC" might denote a particular feature or design of the panel (for example, a certain enclosure or a model for specific environments like commercial or residential).
