How do I choose an appliance fuse?

How do I choose an appliance fuse?

Selecting the correct fuse

1. Fuses come in various ratings, but the common sizes are 3 A, 5 A and 13 A.
2. The current flowing through an appliance can be calculated using the equation:
3. Electric power P = voltage V x current I.
4. P = VI.
5. Once the current is known the next highest fuse rating is chosen.

What is the difference between DC and AC fuses?

With AC circuits, the current is crossing the zero potential at 60 or 50 cycles a second. This helps in breaking the arc that forms when the fuse element melts and creates a gap. In dc circuits, the voltage does not go to a zero potential, making it more difficult to suppress the arc in the melting element’s gap.

What are the things to be considered when replacing fuses?

While you should be mindful anytime you replace a fuse, replacing a blown fuse in an electrical panel requires additional safety precautions.

• Be sure to turn off lights and unplug devices and appliances so you can prevent overloading the new replacement fuses.
• Next step is to disconnect the power to the fuse box.

How to calculate fuse sizing for small motor?

But for electronics loads such as circuits, electronics transformer, small motors, the fuse sizing will be the 1.1 times of the full load current or 1.1 times of the total power in watts P (W) is divided by the applied voltage V (V). Fuse rating formula for electronics circuit,

How to calculate fuse rating for individual circuit?

For individual circuit, the fuse rating should be 1.5 times of the full load current. For example, let we calculate fuse rating for a 230 V, 0.8 pf light panel and individual circuits and which contains 10 number of 400A mercury vapour lighting. Hence the fuse standard rating for the panel should be 40A.

Is the fuse size dependent on the load?

One common misconception about choosing the correct fuse size is that it’s dependent on the load of the circuit. Actually, the load of the circuit should have nothing to do with choosing a fuse size.

What is the fuse rating for a three phase motor?

For Three-phase: Motor fuse rating = P kW x 1250 / (1.732 x power factor x V (V-L)) V (V-L) = Line to Line Voltage in volts. For continuous operation, the fuse rating is less than the 125% is not recommended since all the motor is designed to run 120% of the full load rating.