i have 20 computers, how many ampheres should i use? 15 or 30 amp?

Question

pls explain further why?

Answer 1

Some Typical Power Ratings:
- Computer: 120V, 3A (360 Watts)
- LCD Monitor: 120V, 0.35A (42 Watts)

So we are looking at around 3.35A per computer.

If you have 20 computers, you will need,

20 x 3.35A = 67A (max)

Note: 67A is for 120V supply. If you have 240v supply, the current is then 33.5A.

Answer 2

Look at the power consumption of each computer, monitor, printer (laser printers are power eaters). The power is in watts usually. Divide the power by 120 to get the amp draw.
amps = Power(in watts) / Volts
If a computer is 120W, then divide by 120V to get 1 amp.
If a laser printer is 240W then it draws 2 amps for a 120V power system.

The fuse or circuit breaker for THE WHOLE CIRCUIT, that is all the outlets, cannot be less than that total of all the amps plugged into it. Therefore, a 20 amp circuit can support twenty 120W computers, or ten 120W computers and five 240W laser printers, or ten 240W laser printer or another combination that is less than 20amps.

You have to know that other things are not in the circuit also. A sump pump, TV, microwave, or other periodically used appliance will blow the breaker every time it is turned on. Just calculate their amps in the same way. If the microwave oven is 1200W, then it draws 10amp itself.

In order to add more computers to your 20amp circuit, you need another circuit.

By the way, I hope that your question isn;t asking to put a different fuse or breaker in the existing house wiring. If the house was wired with 14 gauge wire, it may only support a 10 or 15 amp circuit breaker. That is the safety valve to keep the wiring from burning. If you add a bigger 20amp fuse to a thin wiring, you will heat the wire like an electric stove without the circuit breaking...a major fire cause.

I added a 20 amp circuit to my computer area for this reason, separating it from the 15 amp circuit. Together I have 35 amps of capacity for the computers and stuff. The 20 amp circuit uses 12 gauge wire, a thicker wire for the circuit. See below.

Answer 3

A computer and monitor use about 150 Watts of power, unless you have the LCD monitors which would probably drop that figure down to about 75 Watts. 20 Computers -> 3000 Watts -> 25 Amps at 120 VAC. I would go for at least a 30 amp circuit breaker.

Answer 4

Be in the safe side. Suppose a PC may consume 200 VA. Since line voltage for USA is 120 volt AC, each PC will take 1.6 Amp. Thus 20 PC will take about 33 Amp. So you must use 30 amp fuse.
Since you are in safe side for this estimation and all PCs may not be turned ON simultaneously, this 30 amp fuse will be OK.

Answer 5

As others have said, you need to find the power requirements of your equipment to find the total amps.

However, there is much WRONG advice on here. You cannot have normal 15A receptacles on a 30A circuit. You can only have 15A circuit if 14 AWG wire, or a 20A circuit with 12 AWG wire. Larger wire can be used, but you cannot use a larger breaker than 20A for normal 15A receptacles. For that many computers you would need multiple circuits.

Answer 6

Each Modern computer consumes 250 Wattage of current. which is equivalent to 250w/230v = 1.087 amp. Hence you requires 1.087 x 20 = 22.74amps preffered 25 amps. see the site below for the relation between voltage, current, energy.