What Size Wire To Run A 100 Amp Subpanel?

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Homeowners install sub-panels either to extend the available circuit infinite of their main console or to connect a distant part of their property to the chief panel. Whatever the reason, it'south essential that the installer correctly connects the sub-panel via a double-pole billow. Safety should be the primary business organization when working on anything with electricity within the domicile. It is recommended to always get a professional to do whatsoever work with electricity.

Typically, you need to connect a 100-amp sub-panel to the main panel via a correctly-sized breaker of 100 amps. You tin all the same use a 100-amp sub-console on a lower-amp breaker, just you will non be able to utilize the total 100-amp capacity of the panel. Installing a 100-amp sub-panel on a 200-amp billow would let the wires to overheat.

In this article, we will examine the uses of sub-panels and breakers in delivering power around the home. Nosotros volition besides look at the correct fashion to install the sub-console while ensuring that safety is always the showtime consideration.

If you lot want to find the best breakers, click here.

Sub-Panels and Their Uses

Your electric company supplies power to your dwelling via the electric meter to your master service panel. This circuit billow panel protects your wiring, and the breaker design trips if at that place is an overload.

Should the capacity of this main panel be insufficient for the needs of the dwelling house, many homeowners then install a sub-console.

An electrical sub-panel feeds off the chief panel and is a mini version of that chief panel. Electricians refer to these as a service panel or excursion breaker sub-panel. People install sub-panels for a diverseness of reasons, such as separating electric areas, creating space for circuits, and running new cables for a remodel.

Separating Electrical Areas

You may want to split up the electric functions in one area of your holding from some other. For case, if there is a separate dwelling house on the property or an office, it tin can be useful to take carve up circuits.

Creating More Infinite for Circuits

If the principal panel has run out of spaces to install new circuit breakers, then y'all may demand to install a sub-panel to allow for additional circuits.

Remodeling

When remodeling an surface area of your dwelling house, it can be useful to run new cables to a sub-console near the new space. Information technology can be challenging to reroute multiple wires, and this tin be a solution since you only have to route one main cablevision needs to the main panel.

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Sub-Panel Capacity

When adding a sub-panel, it is essential to consider how much capacity yous require and how much the chief panel can spare. If your master panel does not accept extra capacity, then you might demand to consider upgrading it before installing a sub-panel.

For example, when adding a 100-amp sub-panel to ability a shed or garage, you should ideally have a 200-amp chief console and then that adding the extra power demand does not risk overloading the system.

In theory, you tin can add together a 100-amp sub-panel to a 100-amp main panel, but the master console would have to have a pregnant unused capacity to allow this.

Also, the sub-console must be correctly-sized for its needs. You lot will need to consider the actress load that you lot crave to make up one's mind what sized sub-panel to install. It'due south a good idea to add together a small amount of spare capacity for whatever time to come needs.

Electric Circuits

Each breaker on the main panel or a sub-panel connects a circuit of power somewhere in your domicile. These are generally 120-volt circuits (15-20 amps) that run most household items. In bedrooms and living rooms, there are usually xv-amp circuits that connect lighting and outlets in a specific area. 20-amp circuits typically supply areas similar kitchens or garages where there are larger appliances.

Some large appliances, such as air conditioners or range ovens, may even have a dedicated circuit due to the amount of power they need to pull. This is usually the case if they require more than than half the excursion'due south capacity. These circuits are mostly 240-volt circuits that tin can pull twenty to lx amps.

On the primary console, there would be a breaker specifically linking the sub-panel to the main supply. The sub-panel would, therefore, control a branch excursion from the chief panel. This branch circuit would so get divided into multiple smaller circuits fed from the sub-panel.

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Breakers

A billow is a switch that can be manually shut off or automatically tripped when in that location is a failure in the system. This is a safety feature that enables the system to protect itself from electrical fires. The billow'southward rating in amps indicates the maximum amount of ability of the excursion should provide.

A breaker consists of a fixed contact and a moving contact called electrodes. These contacts are airtight when a breaker is operation commonly. If at that place is a fault, the contacts will automatically open up, and you tin can also open them manually.

When the contacts are separated, an arc is struck betwixt them, and this is known as the arc phenomenon. The current will go along to flow until this arc discharges, and the circuit is therefore interrupted. A circuit breaker, therefore, seeks to disrupt this arc as fast every bit possible.

On the main panel, there will exist circuit breakers for each circuit. If there is a sub-panel, so there will be a large breaker that connects to it. This breaker would supply the feeder excursion that powers the sub-panel and would be a double-pole breaker with double-size levers.

Single-Pole and Double-Pole Breakers

Electricians typically use unmarried-pole breakers for the smaller 15- to twenty-amp circuits. These consist of one hot wire and one neutral wire. The use of double-pole breakers is for larger circuits and consists of two hot wires connected by a neutral wire.

Single-pole breakers have narrow switches on the console and tend to ability appliances such equally lighting, fans, computers, televisions, etc. If there is a system mistake or if it is overloaded, then the single breaker will trip to protect the circuit.

Conversely, double-pole breakers have double-switches. They commonly power large appliances such as electric ranges, air conditioners, electric water heaters, or a sub-panel. If there is a curt circuit acquired by a fault or overloading on the circuit, and then both switches will trip (source).

Connecting a Sub-Panel

Connecting a sub-console can exist a solution for various electrical challenges. The size of the sub-console will depend on what it volition ability every bit well as how much excess capacity exists in the master panel. It connects to the main console via a double-pole breaker and cannot exceed the amperage of the main panel.

Importantly, the breaker feeding the sub-panel must be correctly sized. A 100-amp sub-panel tin be connected past a breaker upwards to 100 amps, depending on its requirements. You could use a smaller breaker, but then that would limit the load that the sub-panel would be able to deliver.

Generally, when installing a 100-amp sub-panel, it would be connected by a 100-amp breaker.

What's also important is using the correct-size wires to feed the sub-panel (source). When installing a 100-amp sub-panel, yous volition need to use either 4AWG (American Wire Gauge) copper cable or 2 AWG aluminum, three-conductor cable.

Aluminum cable is cheaper than copper cable and carries the risk of corrosion. Iii-conductor cable comprises iv wires — two hot wires, a ground wire, and a neutral.

The panel itself must be fastened to a wall or other secure surface. If it is installed outside, and then information technology must exist one that has been approved for exterior use. It will demand at least three-feet clearance on all sides and be easy to accomplish and so you can admission switches. Y'all cannot install information technology in a bathroom or a closet.

The sub-panel connects to the main console via a circuit billow in the master panel. This is known every bit a feeder billow and is a 240-volt circuit billow. Because it is a double-pole billow, information technology volition accept up two adjacent spaces on the primary panel, then you need to have or create chapters for that.

Connecting a sub-panel is best washed past a qualified electrician. Many local codes make information technology illegal to install your own sub-panel, and some don't allow homeowners to do any of their ain electrical piece of work (source). Installing a sub-panel volition involve the post-obit steps:

Run the feeder cable from the main panel to the sub-panel.
Connect the 2 hot wires to the sub-panel hot bus bars.
Connect the neutral wire to sub-panel neutral bus bar.
Connect the grounding wire to sub-panel grounding double-decker bar.
Adhere the hot feeder wires to the feeder breaker at the main panel.
Connect the feeder neutral and ground wires to the principal console.
Connect the feeder breaker into the main panel.

Once connected, a sub-panel tin can and so be prepare up with individual circuit breakers for the circuits it is being installed to service. Ultimately, the connections should all be concealed by a cover, and a homeowner should merely access the breakers.

Consult An Electrician

An article such as this cannot cover all eventualities and codes that utilize in all countries and all local municipalities.

For this reason, also as for the safe of you, your family, and your home, it is all-time to consult with a local electrician before whatever type of electrical work.

When electricity is concerned, a little bit of knowledge can exist deadly, and it is not worth taking the hazard just to save a picayune money.

Final Thoughts

Any type of electric work should never be considered a DIY chore with little bones knowledge of electrical piece of work. Sub-panels offer great convenience to the homeowner. They can provide proximity to excursion breakers, and they can reduce the amount of wiring required to add together a new area to your power source. They also enable homeowners to update or increase their power requirements for a relatively low toll.

You must have them correctly and safely installed, following all the required guidelines and codes. Wherever possible, sub-panels should be installed by a qualified electrician so that breakers and wiring are correctly sized, and the installation is every bit safe equally possible to prevent any avoidable electrical faults.