How many watts is safe to use in a 240 volt outlet?

Answer 1

There are two important formulas when calculating Voltage, Current, Resistance and wattage. Ohm's Law states that Voltage = Current x Resistance; and Watts = Current x Voltage x PF, where PF is the power factor and has a value from zero to 1. For a purely resistive load the PF is 1 so the formula is simplified to Watts = Current x Voltage. PF decreases for loads like motors or lights with ballasts.

You would need to know the current rating of your breaker. For example if a 20A breaker is available and load is resistance only them you could support 220 * 20 or 4400 watts. However you only size load for 80% or rating so in the example the wattage would = 3520 watts or 3.52KW.

Answer 2

It is not the voltage that defines whether it is safe or not.

It all depends on the dimensions of your electrical wires.

In a properly installed electrical system in a home, there is a fuse box. It is the fuses that in the end will limit the current and wattage possible.

As a general rule, a 10 Ampere fuse will provide you with 2400 Watts

A 16 Ampere fuse, 3840 Watts.

Most normal outlets are connected to 10, 13 or 16 Ampere fuses. For heavier loads than 16 Ampere, you have to use special outlets with a different design.

Note:

As the load on the grid varies, so will your outlet voltage.

You may have 240 Volt during nighttime when the load is low.

At dinner time, when most people are using electricity to prepare food, the voltage may drop to 220 or even below.

This change in voltage will also work as a limiter regarding your fuses.

Example: 220 Volt, 10 Ampere is only 2200 Watts.

Extra information:

If only thinking about your electrical wiring, then three factors have to be considered regarding the wattage you apply (or in fact drain).

1. Distance (length of wiring from primary source).
2. Thickness (the diameter of your wiring).
3. Material (Copper, Aluminum, Silver, etc).

1. If the distance is long, then the resistance in the total length of the wire is high. This in turn with increased wattage causes the wire to heat up and ultimately the insulation will melt and wires might/will shortcut.
2. Thicker wires have lower resistance and higher wattage can be drained over a longer stretch.
3. Copper is a superb conductor but is costly. Aluminum is also a superb conductor but wires need to be thicker in order to carry current compared with copper. Silver is the best there is and can be thinner, but it cost a fortune.

3-4 meters of a thin ordinary solid copper wire of 1 mm diameter should be able to provide you with 3600 Watts if the voltage is near 240v. (16 Amp fuse)

If the stretch is closer to 20-30 meters, then only 2200 Watts should be drained. (10 Amp fuse)

If the stretch is close to 50 and beyond, this will further limit Wattage and great care should be taken in order to prevent an electrical shortcut due to melting insulation.

Answer 3

The answer depends on the fuse you are using. If it is 15 amps, the power equals voltage times amperage. 240 volts times 15 amps = 3600 watts.

Answer 4

Depends on how much the current is. Current multiplied by voltage = wattage. So if you had a 240 watt device using 240v the current would be 1 amp. A 960 watt device would be 4 amps.

Answer 5

A 220V service rated for 200 Amperes can supply 44 kW at Unity -- less at lower than Unity power factors.

Answer 6

Amps, volts and watts are interrelated, but you need to do a little math. Amps * Volts = Watts

Answer 7

240 watts for every ampere of current that flows

Answer 8

2400