Do people have any knowledge about using this power supply, and what should be the best input setting?
Do people have any knowledge about using this power supply, and what should be the best input setting?
...so I began a reply and labeled the device as lop-500 as the "power adapter" while referring to the hdplex unit as the "power supply," even though both function as power sources. That approach is somewhat complex. It would be clearer to specify that the power adapter delivers a maximum of 750 watts. The device doesn’t simply emit power; it waits for the connected equipment to signal its power needs. I think if the computer were to demand 750 watts from the supply, it would likely draw too much and cause a failure. That outcome shouldn’t occur. Your system doesn’t appear to require nearly 500 watts, let alone the 750 offered by the adapter. Having extra capacity is usually preferable. I haven’t checked the costs, but it seems you could fit a compact power supply inside an external enclosure to achieve the same result. Standard PC power supplies include various protective features to safeguard against shorts and sudden high draws. For instance, a powerful video card linked to a low-wattage supply could trigger protection circuits to cut power and prevent damage. Cheaper supplies often rely on basic fuses, while higher-end ones automatically reset when disconnected. This explains why professional power supplies cost more than what you’re considering.
I had a chat with the manufacturer's customer support, and they explained that the power supply works better at higher voltages. They suggested using 24 volts or more and advised keeping the amperage under 40. That amount of power seems quite strong, especially at 48 volts. However, this was the advice I received. They mentioned that 24 volts and above improve efficiency, so I was told to limit the amps to under 40. The power supply I planned to use is significantly less powerful than 40 amps.
The connectors are probably rated for 40 amps at 12 volts, which equals 480 watts. In theory, you could try 40 amps at 48 volts, but the physical connection wouldn’t handle it well since other parts of the power supply aren’t designed for that much power. The highest the power supply would attempt at 48 volts is about 10.42 amps. If the company claims better performance at higher voltages, I’d give them credit. You can find adapters that deliver 24 or 48 volts. There are two types of efficiency to consider. Power transmission generally benefits from higher voltages. The massive power lines you see from power plants to cities operate at over 100,000 volts to minimize losses over distance. The issue is most electronics are built for 12 volts or less. A lot of energy is wasted when converting between these levels, and the greater the difference, the more loss occurs. It’s hard to ignore this concern, but I’d just ensure any purchase includes the correct wattage rating. Watts are a clearer way to measure usable power.
Thank you for your response. I've just submitted a new query possibly related to the same component. It concerns this identical power supply.
This applies to regular ATX power supplies. They perform slightly better at 230V than at 120V AC.
If I could decide, I'd power your HDPLEX with 48V DC. That would minimize current draw and allow using thinner wires.
Remember, no power supply is perfectly efficient—you can anticipate about 90% efficiency, with the remaining 10% lost as heat.
To achieve full 500W output from your HDPLEX, you'll need around 550W input.
Dividing 550W by 48V gives roughly 11.46A (about 12A).
Select wiring rated above 12A for the HDPLEX input when using 48V.
However, if you run it at 12V, it will draw around 46A (assuming 90% efficiency) for the same 500W output.
Any DC power supply you use will have its own typical 10% loss, so the overall system efficiency would drop to about 80%.
Thank you for your reply
I plan to operate it at 27 volts with 18.50 amps, producing 499.5 watts just below the 500 watt limit. I’m using a Mean Well LOP-500-27 that offers various voltage options from 12 to 54 volts at around 500 watts.
I chose to stick to the middle of the voltage range and keep under 500 watts for safety with this power supply. It’s a medical device, so it should operate efficiently and rarely shut down. I believe it has about 90-94% efficiency.
I’m unsure how it functions since it runs at 320 watts without a fan but can reach 500 watts with one. No instructions are given on adjusting the wattage on the power supply. I’m guessing turning on the fan would increase the output, or there might be a switch on the board.
Do you know how to change the wattage setting on the Mean Well LOP-500-27? I’d like to adjust it from 320 to 500 and might share this later elsewhere or as a new post.
Ignore ideas about "limits". Most reliable power sources can deliver a bit more current than they advertise. Often the OCP (overcurrent protection) won’t activate until 130% of the rated capacity (a 30% overload), meaning a 500W unit won’t trip until it’s producing around 650W.
A PSU labeled for 500W should be able to run continuously at that level, as long as the room temperature stays within the limits set by the manufacturer.
If your PSU has a nominal 500W rating, it’s designed to operate smoothly at 500W under normal conditions. However, keep in mind the typical efficiency rate is around 90%. To achieve the stated output, it will consume roughly 550W from the input side. This calculation shows a current of about 20.37A, not the 18.5A mentioned.
When a device requires more than 500W, the PSU will supply extra power until protection kicks in or something fails. Assuming a standard 10% overload margin, a 500W unit can handle up to 550W before reaching its limit. This translates to roughly 22.22A, not 18.5A.
It’s worth noting that the PSU’s input voltage must stay within acceptable ranges. A 27V DC supply might be sufficient for most applications, though efficiency rises with higher voltages.
The efficiency range of 90–94% mainly reflects peak performance at half maximum power (250W in your case). At lower voltages like 12V DC, efficiency drops to about 90%, while at higher voltages like 48V DC, it can reach around 94%.
A typical graph for a 550W ATX PSU shows similar behavior. Efficiency falls quickly when the load is below 100W. For example, if your system uses 50W idle power, efficiency drops to 84%, not the advertised range. Also, efficiency decreases significantly above the midpoint of 250W up to 500W.
The PSU can handle up to 320W without a cooling fan, as long as the room temperature doesn’t exceed its limits. For outputs between 320W and 500W, a fan is necessary.
Making a medical PSU doesn’t affect efficiency or protection—it just ensures compliance with safety and regulatory standards.
There are several reasons a PSU might fail, including overload conditions. Refer to the overload protection documentation for more details.
You don’t switch between fixed power limits; your computer adapts its power draw dynamically based on needs. The PSU simply provides whatever current is required from the 27V input. Its demands change depending on the workload.
At any moment, a CPU might need anywhere from 63W to 265W, depending on processing requirements.