What to understand by overloading?
Circuits and wires are designed to carry a specific value of current. If for any reason the current passing through these cables is greater than what they can handle , there is a risk of OVERLOAD. The cables get heated up , melt and can potentially get fire. An overload is therefore a direct consequence of a high value of current not voltage! Many protective devices have been listed to limit the damages caused by this situation . Though reliable in most cases, knowing the installations which can save your family’s life and yours is still important. So let’s get started!
Below are some of the most important installations that lead to overload .
- Plugging several power-hungry items or tools on the same circuit. When many appliances are running at the same time , on the same circuit, there is a risk of overload. It is not just any type of appliances, but those with a considerable amount of power. Note that a circuit cannot handle more than 80 percent of the maximum load. for a 15-amps circuit, the safe margin at a given moment will be 1,440 watts: 120 v x 15 A= 1,800; 80 percent of 1,800=1,440 watts. It means that if the total load at a given period is greater that 1,440 watts for a 15-amps circuit, there is an overload. Similar calculations are applicable for a 20-amps circuit and give 1,920 watts. Such appliances should have their own dedicated circuit ( air conditioner, electric dryer, dishwasher etc). If not, they can melt wires and even burn them. Appliances that need their own dedicated circuits These appliances are called power-hungry appliances because they use too much power in a small amount of time. when such situation occurs an “over-current protective device” installed at the main panel will trip. It can be a circuit breaker or a fuse.
- The use of extension cords as permanent wiring. Extensions cords are very useful as temporary solutions . They are not designed to carry the power running by the appliances they are connected with. This is the reason why they should never be permanent. An extension cord is like an intermediate branch that you create on your own. But in this case , since it has not be set and sized by your electrician, it’s not safe and can become a serious issue. There are many parameters you didn’t take into account like the cross sectional area of the extension cord or the current needed by the appliance you are going to use.
- Outdated installations/wiring: Knob-and-tube wiring is not effective as it was few decades ago. This installation is not grounded and does not offer a proper protection to an equipment. It’s crucial to Check the wiring installed at home and if it’s an old one, then consider replacing it by a safe and more appropriate wiring. Skilled Electricians are trained for that and are aware of the norms and rules applicable in your communities. So it’s better to reach them out. Aluminium wiring also, has been prohibited many decades ago. Although cheaper than copper it was dissipating too much heat and was not efficient over time.
- Non conventional sizing: When cables are wrongly sized for circuit breakers they are useless. The size of the wire is critical; Different wire gages are meant for different amperages. The current that a cable can handle must be as the same as the circuit breaker. Let’s take an example: If you have A #12 wire gauge which carries 20-amps then It will be safely protected by a circuit breaker of 20-amps too. However, if that wire is connected to a 15-amp circuit breaker then a significant amount of current can go through it. both wires and circuit breaker will start heating up. And this is a wasted energy that can increase your electrical bills.
- Mismatch circuit breakers: It’s not recommended to replace a circuit breaker inside a control panel without the approval of the manufacturer or inspector. The breakers installed in the panels should be the ones set by the manufacturer. A circuit breaker can perfectly fit a control panel but it may be incorrect if not checked by an inspector.
- Faulty connections: A faulty connection is not something to take lightly. It may not appear on the cables, but rather on the terminal of devices. As an electrician, it is Always recommended to check the connections before reconnecting the power supply, or leaving the workplace. But if you are not an expert do not attempt to fix it on your own.
How to prevent circuit overload:
- Install an appropriate and well-designed circuit breaker. Identify which equipment requires its own designated or dedicated circuit . Install a new branch of circuit were needed. If you run many hungry items at the same time, consider having different circuits. You can use different circuits for lights and outlets( which is recommended) 15 and 20-amps for example. This is one of the most important and recommended solutions to prevent circuit overload.
- Install more outlets To limit the use extensions cords. You can also use power surges were small appliances are connected to. By adding new outlets, you keep the branches of circuits safe and free from fire . You can either install a new outlet in an existing branch, or run a new one. It all depends on your skills or the clearance of the main panel. If you can map circuits on your own, and identify which of them create overload, then go ahead. what you will need to do is find a branch that still have enough capacity to add an outlet. If you are not comfortable with the idea on doing the installation on your own, then call an electrician.
- Replace incandescent light bulbs with fluorescent bulbs or energy efficient leds. they will drop your electrical bills.
- Call for an inspector or skilled electrician to check the installation made. Especially if it is an old one. An inspector is here to help, check if everything is correct and ensure that proper safety guidelines are followed with respect to the rules set by its state. old home rewiring
An overloading circuit results from extra and inappropriate connections made by users,young professionals or hobbyists . Outdated or damaged wiring can also lead to such situation. But in each case, they invite electrical fire . So better Have your electrical system properly installed. Always call for electricians or inspectors for works you are not confident with.