Definition: When a circuit carries a current greater than its rated capacity, it is called overloading. The amount of current that flows through an electrical circuit depends on the power rating of the connected appliances. When the current drawn by the appliances exceeds the safe limit for the circuit, it can cause the wire to overheat or it can damage the appliance.
You might have heard the term full load current(FLC) when referring to equipment such as motors, heaters, and generators. It means the winding of the motor or heating element of the heater can safely carry the full load current. What happens if a current of more than FLC flows through the winding? Excessive current flowing through the winding causes increased heat and I2R losses, leading to insulation failure and fire hazards. You are aware that the insulation life depends on the temperature.
You might also have heard about the current carrying capacity of wire. Suppose a wire has a current carrying capacity of 25 amperes, and the electrical load connected to it draws 30 amperes—the excessive current causes overloading and, eventually, insulation failure of the wire.
Causes of Overloading
The following are the reasons.
- When you connect multiple electrical loads on the same socket, it may cause overloading. Suppose the rating of the socket is 15 amperes, and you connect 4 types of electrical loads of 5 amperes rating; it will overload the electrical socket.
- Running all electrical appliances at the same time causes more current in the circuit, and the excessive current in the incoming circuit causes overload.
- Inadequate design of electrical wiring and its protection system can lead to overloading. Ensuring that the electrical system can handle the expected load is crucial.
- The failures or defects in the electrical equipment can cause it to draw more current and overload the electrical circuit.
- The voltage fluctuation, voltage dips, and surges contribute to overloading. Electrical devices may draw more current to compensate for low voltage conditions.
- Overvoltage conditions in the electrical supply system can cause overloading.
- Electronic devices, such as computers, TVs, etc., draw harmonic current and can increase the circuit current above its rated capacity, which can cause overload.
- Improper distribution of the load in a 3-phase supply system causes uneven load on phases and can contribute to overloading.
- The capacitor banks are used for reactive power compensation to reduce the circuit’s current. If capacitor banks are not installed, the excessive current due to reactive load may overload the circuit.
How to avoid Overloading?
Follow these guidelines to avoid electrical overloading and ensure the safety of your electrical systems,
- Know the electrical capacity of the electrical installation.
- Check Appliance Ratings
- Use Proper Outlets and Circuits
- Distribute Loads Evenly
- Install Ground Fault Circuit Interrupters (GFCIs)
- Regularly Inspect Wiring
- Install capacitor banks
- Install Miniature circuit breakers(MCBs)
By following these tips and practicing electrical safety, you can significantly reduce the risk of electrical overcurrent and enhance the safety of your electrical system.
Symptoms of electrical overloading
Electrical overloading can lead to potential hazards. Here are some common symptoms of electrical overloading.
- Discolored Outlets or Wall Plates
- Burning Smell
- Hot Outlets or Switch Plates
- Flickering Lights
- Buzzing Sounds
- Appliance Malfunctions
- Sparks or Arcing
If you notice any of these symptoms, addressing the issue promptly is crucial to prevent electrical hazards, fires, or damage to your electrical system.
Conclusion:
In this article, you learned what overloading is and how to avoid it. The hazards can be minimized, and safety can be enhanced by keeping the electrical loading within the permissible limit.