3000W 12V DC power supply rig


One of my devices requires a 12V DC input and has a 3000W power consumption. I am looking to provide power to this device from a power supply. I found a power supply on digikey, the ET3200-12-069RA, for example, that can provide these power output requirements to my device. However, I am struggling to understand how I can provide the correct input requirements to this power supply. This supply seems like it will work from an input of 120V AC and 14A. My problem is that i can only provide electricity from the outlets available throughout my home. Since each one is rated at 120V AC and 15A, I can only provide a safe continuous amount of 12A max from each outlet. Therefore, is there any way to combine 7A from one outlet and 7A from another to power this power supply? Otherwise, is there an easier way to power my device that has a requirement of 3000W and 12V DC input? I am limited to my outlets and I am looking to combine their output currents for this safely. If there are any suggestions or recommendations, please let me know. Thank you. Can someone confirm the minimum current required to power this power supply at 120V AC input? I also have 1 30A and 1 40A outlet available at 120V AC each.

Per page 9 of the datasheet for the mentioned supply, full rated output is not available when input voltage is below about 180VAC. Supplies such as this are designed for parallel operation however; it’s possible to gang several together in a rack-like system to increase deliverable output power and provide redundancy.

That aside, figuring for a 30A draw from a nominal 120VAC source would be reasonable. Use of the mentioned 40A circuit would be the best choice among those named, though accessing a 240V feed would really be the better option given the power levels in question.

Note also that many loads will draw power in excess of rated values for brief periods of time, and that if electronic supplies are used, they need to be sized to accommodate such surges. Understanding the character of the load is really quite important here.

As for an “easier way,” an appliance requiring 3kW @ 12V is more or less choosing the hard way to start out with. If only intermittent operation is considered, use of automotive batteries as a buffering agent may offer some measure of relief.

Hi Welcome to Tech Forum. For this power supply, your household wall would work fine to input the 120v to power it up. the Max input current is 17A. There is not a minimum, whatever your house current is, would be fine. Please see hook up information on the link below. Glenda

Thank you, would you recommend replacing my 120V outlet with a 240V outlet for this application? Also, how would I set up this power supply for parallel operation? Would I use two power supplies to power my device or do you mean use two input power sources to power one power supply?


To use the mentioned supply at the desired output level, yes, so doing would be necessary.

More detailed information can be found in the datasheet, but the general idea is to connect the current share pins of all parallelled supplies, as well as the outputs. Other products, for example the RCP-1600-12 converter modules in conjunction with the RHP-1UI-A rack module are available which can make the process somewhat more convenient. Though not necessary, if indeed a single instance of the supply mentioned can be made to work in the application.

Thanks, that answers all of my questions except one last concern,

I think I will go with one of my two 240V outlets that I realize can each provide 30A and 40A. Since the power supply ET3200-12-069RA from digikey has a 17A maximum limit, am I not allowed to just plug in this power supply directly to my 240V outlet? I would assume that the power supply will only draw 13A since at 240V this is the current required to produce the 3000W output. Is there any reason why the power supply might draw more than this or more than the 17A limit once I plug it in directly to my 240V outlet? Is there any intermediary device needed to limit the current supplied from the outlet to the power supply or should the power supply automatically draw the required current safely to obtain it’s rated power of 3000W on it’s own?

Thank you

You need to account for the inefficiency of AC to DC conversion, usually on the order of five to twenty percent depending on many variables, so it will draw more than 3000W with a 3000W load. It’s from a reputable manufacturer so you should be able to count on it not exceeding the maximum rating of 17A.

Okay! my primary concern is that my device doesn’t receive more than the 3000W it requires. Since the power supply will draw more than 3000W due to the inefficiencies, will it still be able to supply a consistent 3000W output or will it potentially fry my computer’s circuit board by delivering more than 3000W?
Also, will this power supply be damaged over time by outputting 3000W since this is it’s maximum rating?

Thank you for your help

Power supplies don’t force power into devices, they provide what the device requests as long as the request is within the power supply’s ratings. This is a constant voltage power supply so it will supply 12V from close to zero all the way up to the rated maximum amperes. The powered device dictates how many amperes of current are drawn from a constant voltage power supply.

The maximum rating of the power supply being discussed is 3200W. Because it’s from a reputable manufacturer I’m sure it can provide exactly what the data sheet says it can provide (pages 5 to 9).

The power supply being discussed is not suitable for powering a standard PC motherboard. This is an expensive highly specialized power supply meant to be used to power even more expensive highly specialized gear. Fire, electrocution, and expensive gear damage are all possible if not installed and used correctly.

Thanks! I am trying to set up multiple computers in parallel so I may need a total of 3000W.