## How do you determine the correct fuse for an electrical device?

**To calculate a fuse rating, manufacturers work from a simple equation:**

- Power (watts) = Voltage x Current (amps) What we really want to know with this equation is the current (amps). …
- Amps = Watts / Voltage. So, let’s say we need to work out the fuse rating for a washing machine. …
- 850/120 = 7.08 amps.

## How do you determine what size fuse you need?

B Calculate MINIMUM FUSE AMPERAGE by **multiplying product amperage rating by 125%**. Minimum fuse amperage provides more protection for the wire but may result in nuisance blows. Example: 80A x 125% = 100A.

## What factor is the basis of selecting a fuse?

In short, the following factors should be considered when selecting a fuse for a given system: **Normal operating current**. Operating Voltage. Ambient Temperature.

## What should be value of fuse?

One source suggested a rule-of thumb that the fuse rating should be about **1.5 times the maximum normal mode input current**. If he used this rule, he would use a 4.2-ampere fuse.

## What appliances use 13 amp fuse?

13A Fuse – **Washing machine, dishwasher, microwave, kettle, toaster, iron**.

## What is a 3 amp fuse used for?

In **electrical appliances up to 700w**, you need to use a 3A fuse. And for appliances over 700w, you need to use a 13A fuse.

## What are the standard fuse sizes?

Standard sizes for fuses and fixed trip circuit breakers, per 240.6, are 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 125, 150, 175, 200, 225, 250, 300, 350, 400, 450, 500, 600, 700, 800, 1000, 1200, 1600, 2000, 2500, 3000, 4000 5000, and 6000 amps.

## What is a 5 amp fuse used for?

5 amp sockets are used **on the lighting circuit**, meaning they are switched on and off with the light switches in the room, rather than being used like regular plug sockets. They are designed for appliances that take less than a 5 amp current, for example floor lamps, table lamps and fans.

## What are the 3 types of fuses?

**Different Types of Fuses – Constriction, Working & Characteristics**

- DC Fuses.
- AC Fuses.
- Cartridge Fuses.
- D – Type Cartridge Fuse.
- HRC (High Rupturing Capacity) Fuse or Link Type Cartridge Fuse.
- High Voltage Fuses.
- Automotive, Blade Type & Bolted Type Fuses.
- SMD Fuses (Surface Mount Fuse), Chip , Radial, and Lead Fuses.

## What are fuse ratings?

Fuses come in standard ratings of **3 A, 5 A or 13 A**. The best fuse to use in this example would be the 13A fuse. The 3A and 5A fuses would blow even when the fire was working normally.

## What is Watt formula?

How do you calculate watts? – Watt’s equation. Our calculator is based on the two laws that describe simple electrical circuits. One of them – Watt’s law – states that: **Power = Voltage * Current** – in symbols: P = V * I .

## How many watts is 1 amp 220 volts?

220 watts

In order to know how many watts are in a charge, simply multiply the the amps by the voltage for the current. So 1 amplifiers for 220 volts is equal to **220 watts**.

## How many watts is 12 amps?

Watts and amps conversions at 120V (AC)

Power | Current | Voltage |
---|---|---|

5 watts |
0.417 amps | 12 volts |

10 watts | 0.833 amps | 12 volts |

15 watts | 1.25 amps | 12 volts |

20 watts | 1.667 amps | 12 volts |

## How do you find watts from Joules and seconds?

Watts are defined as **1 Watt = 1 Joule per second** (1W = 1 J/s) which means that 1 kW = 1000 J/s. A Watt is the amount of energy (in Joules) that an electrical device (such as a light) is burning per second that it’s running. So a 60W bulb is burning 60 Joules of energy every second you have it turned on.

## How many watts does a refrigerator use?

The average home refrigerator uses **350-780 watts**. Refrigerator power usage depends on different factors, such as what kind of fridge you own, its size and age, the kitchen’s ambient temperature, the type of refrigerator, and where you place it. Different types of fridges have different power requirements.

## How many watts do I need to power my house?

How many watts does it take to power basic items in an average size house? In a typical home, essential items will average **5000 – 7500 watts** of power to run.

## How do you find efficiency?

**To calculate the efficiency of a machine, proceed as follows:**

- Determine the energy supplied to the machine or work done on the machine.
- Find out the energy supplied by the machine or work done by the machine.
- Divide the value from Step 2 by the value from Step 1 and multiply the result by 100.
- Congratulations!