How to calculate safe circuit loads

By

The majority of the circuits in your home are either 15-, 20-, or 30-amp circuits. They are located within your electrical circuit panel. But what is an electrical panel? An electrical circuit breaker panel is the main distribution point for electrical circuits in your home. It usually provides between 100 and 200 amps of power to your home, depending on your home’s load demand. Power comes into your home from the utility company, through a service entrance.

It flows through an electrical meter, through an electrical disconnect and then to the main breaker in your electrical panel.
First, Locate the Main Breaker

The main breaker is located at the top or bottom of two rows of breakers, depending which way the panel is mounted. The main breaker is marked with the value of protection (like 100 amps) on the breaker handle. This breaker is either factory mounted or can be added by either bolting it in or snapping it into place. Bow you may ask what the main breaker is and for good reason.

Your electrical panel is full of circuit breakers, running from top to bottom of the service panel. The odd numbered breakers are located on the left and the even numbered circuit breakers are on the right. Atop the many circuit breakers is a larger circuit breaker that is used to turn the entire circuit breaker panel on or off. It is known as the main breaker. It plays probably the most important function in the whole circuit breaker panel.

It is a means of disconnect for the entire panel. But you may ask what makes it different from the rest of the circuit breakers within the panel.

So, what is the main breaker anyway? You'd think that it is something special having a name like that. Actually, the main breaker is the breaker that the feeder wire connects to.

This breaker is a two-pole breaker that is connected to 240 volts to power your home. The main breaker acts as the disconnecting means to the entire power load of your breaker box. With it off, there is no power being fed to the buss bar that feeds the branch circuit breakers. These dish out power to everything you power up in your home, but to a limit of the breaker size and this is called the electrical load.
Now, Calculate Safe Circuit Loads

But how much should you actually load each of these circuits to maintain a safe circuit load?

Electrical circuit load capacity is the total amount of power that your home actually will use. In order to decide how big of an electrical service is needed in your home, one has to do a little math check up . Older homes often only had a 60-amp electrical service, connected to a fuse panel. I actually lived in one that only had 120-volts coming into it. That's right, no 240-volt service! Now homes have 100- or 200-amp electrical services.

Calculating how much power both you and your electrical appliances use is necessary to calculate this number. As technology continues to advance, it seems we add more and more electrical loads to our home. I'm often asked how to figure this load and foresee the additional electrical load additions in the future.

It really is pretty simple if you know what to look for and how to add up the loads.

To determine this figure, you must implement ohms law. By simply multiplying the amperage times the voltage, you’ll get the total wattage capacity for the circuit. However, what we’re looking for here is the total safe amperage capacity to load the circuit.

So to determine this, we simply multiply the total wattage times 80%. To demonstrate what these figures look like, look at the chart below for these common circuit amperages used in homes. The figures are based on 120-volt circuits.
Typical Home Branch Circuit Sizes

15-amp Circuit
Total Wattage Capacity: 15 amps x 120 volts = 1,800 watts
Safe Wattage Capacity: 1,800 watts x 80% = 1,440 watts
Safe Amperage Capacity: 15 amps x 80% = 12 amps

20-amp Circuit
Total Wattage Capacity: 20 amps x 120 volts = 2,400 watts
Safe Wattage Capacity: 2,400 watts x 80% = 1,920 watts
Safe Amperage Capacity: 20 amps x 80% = 16 amps

30-amp Circuit

Total Wattage Capacity: 30 amps x 120 volts = 3,600 watts
Safe Wattage Capacity: 3,600 watts x 80% = 2,880 watts
Safe Amperage Capacity: 30 amps x 80% = 24 amps

Comments

Post a Comment

Popular posts from this blog

Home electrical wiring and connections, what you need to know

By
Image
It's time to tackle some wiring projects in your home, but where do you begin? It's important that you know what you're dealing with before you start, so a little lesson in 'Wiring 101' is in order. From understanding the different types of wires you'll find to installing switches, outlets, and a few major appliances, let's look at the basics of home wiring.     01 of 09     The Common Wires in Your Home     Before you begin your first DIY electrical project, you should learn a little about the wires you'll be working with. Wires vary greatly and each is designed for a purpose.     The wiring in your home is chosen to accommodate the load it must carry as well as the conditions it will be exposed to. Some are designed for indoor use while others can be buried. Some are for your panel while others hook up your lights and outlets.     It may be confusing at first, but you will probably deal with only a few types of wire in your home.     02 of 09   
Read more

How to install Gear switch

By
Image
First we define the word switch gear? a switch gears are a combination of disconnect switches or circuit breakers used to control, protect and isolate electrical equipment. The switchgear consists of a cubicle unit that is attached to a lower frame and they help in identifying faults found in an electricity network such as generating, distributing r transmitting and helps in turning off power. You can call it TP&N OR SWITCH GEAR Electric switchgears are the heart beat of any company facility’s electrical system. The switchgears works as the intermediary between the incoming electricity from the utility companies and all other electrical circuits within the facility. They are of many  voltage classes; we have the low voltage (less than 1 KV), the medium voltage (1 KV to 75 KV), high voltage (75 KV to 230 KV) and the extremely high voltage (Above 230 KV). These switch gears can pose a serious risk to workers and if there are accidents, the likelihood of death is very high. It is th
Read more

Pool electric

By
Image
It’s hard to imagine that a swimming pool has very intricate electrical requirement and they are by no means simple. Water and electricity make a deadly mix so watch out! This is not something for fun and games. This is why professional electrical contractors always follow strict protocols when doing the wiring for swimming pools. The electric requirements of a swimming pool comprise of a motor, pool lights, and filtering equipment. Electrical Pool Requirements All electrical wiring must be at least 5 feet away from the pool. The wires must also securely run through a non metallic raceway system or must be installed within a conduit. Electric pool equipment must also be installed in rooms or pits that have adequate drainage to prevent water accumulation. There must always be a failsafe method to disconnect all ungrounded conductors and the disconnection method must be accessible at least within 50 feet of the equipment. We all love to have underwater lighting in our swimming pools.
Read more