EVGA

What is the rating for my PSU wall cable?

Last Update: 2020/02/20 15:25

Regardless of the power supply unit you are using, there is an international standardized requirement for current rating which all devices must adhere to in order to be certified by their respective authorities to ensure safe operation. The IEC 60320 Standard lists the appropriate limitations for the use of your typical AC power connectors.

On EVGA power supplies, there are two connector types in use:

C13/C14 coupler (below 1500W) C19/C20 coupler (above 1500W)

 

For those unfamiliar with how watts (W) are calculated, power is determined by the potential applied (voltage, measured in Volts) multiplied by the rate of flow (current, measured in Amperes, aka 'Amps'):

Try it:

W = V * A
x

Warning:

Cannot divide by 0

Feel free to read more about history and usage of the Watt here: https://en.wikipedia.org/wiki/Watt

By using simple algebra, we can easily calculate any of the required information as long as we know both of the other details. Since you can find your PSU's wattage on the side of the box, you only need one more piece of information to find the rating for your cables. Fortunately, if your system is going to be plugged into a public source of power, chances are that your voltage is set to a specific value depending on where you live.

In the US, the mains voltage for a common residential outlet NEMA 5 Outlet

is ~120V@60Hz; this does not included appliance outlets, which have their own rating. The following chart is calculated using this voltage, however I have noted each formula to calculate the specific requirement using the calculator provided above. You can look up your country's rating here: https://en.wikipedia.org/wiki/Mains_electricity_by_country and enter it in the Volts textbox.

Please note that these gauge measurements are in reference to units shipped in North America using the AWG standard. This may NOT match the exact specification of units sold internationally.

AC Power Info
Wattage Mains Voltage Formula Max Current Wire Gauge
(Rating in Amps)
1600 W 120 V 1600 / 120 = 13.33 13.33 A 12 AWG
(20 A)
1300 W -
850 W
120 V 1300 / 120 = 10.83
850 / 120 = 7.08
10.83 A
7.08 A
16 AWG*
(13 A)
*EVGA 850 BQ uses a 14 AWG cable rated for 15 A
750 W (and lower) 120 V 750 / 120 = 6.25 6.25 A 18 AWG
(10 A)

Generally speaking, as long as your cable rating (in Amps) is greater than the max current drawn by your PSU model, you should be able to draw the necessary power for the system safely. Notice that the provided cables provide are rated in excess of the requirement as this will reduce concerns of heat during operation. If you do not know the rating of your power cable, please contact the manufacture of that cable before attempting to power your EVGA PSU to avoid any potential damage.

Typical household appliance cables are rated for 10 A, however the gauge of the wire can usually be found printed on the sleeving to provide more accurate information for your reference.

Click here to see information about the ATX DC power specifications

For more information about the basic principles of electricity, CD Power has an excellent article about the subject here - "Understanding the basic principles of electric power"