## How do you calculate motor fuse rating?

Formula to Calculate the Fuse Rating

V for voltage in volt); I for current in Amps. The fuse rating can be calculated by dividing the power used by the appliance by the voltage going into the appliance. I (Amps) = P (Watts) ÷ V (Voltage).

## What is rating of a fuse?

The maximum value of safe current allowed to flow through a fuse wire before it melts is called fuse rating. … If a fuse of higher rating is used, it will not blow and protection of the circuit will be achieved. If a fuse of lower rating is used, it will blow before the circuit is fully loaded.

## What type of fuse is best for motor protection?

Time delay fuses

## How many watts can a 5 amp fuse take?

Fuse ratings45 AMPFor circuits of more than 13kw (13000 w)13 AMPFor appliances between 700 and 3000w (3kw)5 AMPFor lighting circuits. The maximum permissible load of a lighting circuit is 1200w or 12* 100 watt lamps3 AMPFor appliances up to 700 watts, such as table lamps and alarm clocks3

## How do you size a 12v fuse?

Easy Way

- Find the continuous amperage of the device you are trying to power and multiply that number by 1.5, then round up to the nearest fuse size you can find.
- Cross check that fuse size with the maximum fuse size chart below and verify that your fuse size is below the maximum fuse size listed in the chart.

## How many amps is 3 horsepower?

Common Horsepower to Amps ConversionsHorsepowerAmpsVoltage3 HP20.7 A120 V3.5 HP24.2 A120 V4 HP27.6 A120 V4.5 HP31.1 A120 V11

## What is full load current of a 3 phase motor?

All are given at the nameplate details. Look at the above formula, the three-phase full load current is equal to Power divided by the 3 times of product of line to neutral voltage and power factor. Here three-phase full load current is equal to the power divided by 1.732 times of line to line voltage and power factor.

## How many amps does a 1.5 HP 3 phase motor draw?

AC Motor Full Load AmperesHP200 Volts380-415 Volts1/22.51.33/43.71.814.82.31.56.93.323

## How do you create a fuse rating?

In order to select the right amperage of the fuse, you first need to know the full-load steady-state current of the circuit at an ambient temperature of 25º C (68º F). Once the current value is determined, then a fuse rating should be selected as to be 135% of this value (taken to the next standard value).

## What is Max series fuse rating?

The module manufacturer also lists the maximum series fuse rating. This value dictates the largest size OCPD that can be used — typically modules have 15A or 20A series fuse ratings. … Therefore, if three strings are placed in parallel, the output circuit OCPD’s rating would be calculated as: 32.7A × 1.25 = 40.8A.

## What is minimum fuse rating?

For the lighting circuit, the fuse current rating should be minimum 2 times the full load current of the total number of lighting. For individual circuit, the fuse rating should be 1.5 times of the full load current.

## Why is it better to use a circuit breaker than a fuse?

The breaking capacity of a circuit breaker can be greater than equivalent fuses (up to 150 kA). And under overload conditions, a circuit breaker can trip up to 1000 times faster than a fuse. Some circuit breakers also provide exceptional fault current limitation, a capability previously associated only with fuses.

## What should motor overloads be set at?

2) Thermal Overload Set Incorrectly-The basic requirement for overload protection setting for motors is 125% of their full-load current according to the NEC; however, it makes sure you read the overload relay instructions.

## Do all motors need overload protection?

Most other continuous duty motors having a marked service factor of not less than 1.15 or, with a marked temperature rise not over 40 degrees Celsius, are required to have overload protection rated at 125 percent of the motor nameplate full-load current rating.