Branch circuits are the circuits in your home that distribute electricity from the main circuit breaker panel to the various outlets lights and appliances throughout your house. The branch circuit breaker or fuse protects the circuit from overloading. The size of the branch circuit breaker or fuse is determined by the load (amperage) on the circuit. The load is determined by the number and type of lights and appliances that are on the circuit.

The branch circuit rating is the amperage that the circuit can safely carry. This rating is usually printed on the switch or fuse. The rating is determined by the wire size and the number of devices (lights outlets etc.) on the circuit. The rating is a safety factor and is usually 80% of the wire’s maximum amperage capacity. For example a 15-amp circuit that has 12-gauge wire is rated for 1875 watts (15 amps x 125%).

The National Electrical Code (NEC) requires that branch circuits be protected at their maximum load. Overloading a circuit can cause a fire. The NEC requires that branch circuits be sized so that the load does not exceed 80% of the circuit’s capacity. This is called the derating factor and is a safety factor that allows for unexpected surges in the electrical demand (load) on the circuit.

The NEC also requires that branch circuits be protected against short circuits and ground faults. A short circuit is a condition where the current flows through a conductor that has a low resistance. This can happen if the conductor comes in contact with a metal object or another conductor with a lower resistance. A ground fault is a condition where the current flows through the ground instead of through the intended circuit. This can happen if the insulation on the wire is damaged or if the wire comes in contact with a metal object.

Branch circuits are typically rated for 15 or 20 amps. The NEC requires that branch circuits be protected at their maximum load. Overloading a circuit can cause a fire. The NEC requires that branch circuits be sized so that the load does not exceed 80% of the circuit’s capacity. This is called the derating factor and is a safety factor that allows for unexpected surges in the electrical demand (load) on the circuit.

The NEC also requires that branch circuits be protected against short circuits and ground faults. A short circuit is a condition where the current flows through a conductor that has a low resistance. This can happen if the conductor comes in contact with a metal object or another conductor with a lower resistance. A ground fault is a condition where the current flows through the ground instead of through the intended circuit. This can happen if the insulation on the wire is damaged or if the wire comes in contact with a metal object.

Branch circuits are typically rated for 15 or 20 amps. The 15-amp circuit is the most common and is used for most of the outlets in your home. The 20-amp circuit is used for heavy-duty appliances such as clothes dryers and ranges.

## What is the rating of a typical branch circuit?

Answer to Question1: 15 or 20 amperes

## How many branch circuits are allowed on a typical residential circuit breaker?

Up to 8

## What is the minimum conductor size allowed for a 15 ampere circuit?

14 AWG

## What is the maximum number of outlets allowed on a 20 ampere circuit?

12

## How many branch circuits are required for a typical kitchen?

At least 2 one for the refrigerator and one for the other appliances

## What is the maximum conductor size allowed for a 20 ampere circuit?

12 AWG

## How many watts can a 15 ampere circuit safely carry?

1800

## What is the maximum number of outlets allowed on a 15 ampere circuit?

10

## How many watts can a 20 ampere circuit safely carry?

2400

## What is the minimum conductor size allowed for a 20 ampere circuit?

12 AWG

## How many branch circuits are required for a typical laundry room?

At least 1

## How many branch circuits are required for a typical dining room?

At least 1

## How many branch circuits are required for a typical living room?

At least 1

## How many branch circuits are required for a typical den?

At least 1

## How many branch circuits are required for a typical bathroom?

At least 1