Are you asking about powering a large workstation setup with three 4090 power supplies and two 1600W units?
Are you asking about powering a large workstation setup with three 4090 power supplies and two 1600W units?
No way! Each CyberPower UPS is only rated for 3 minutes at 900W (full power). Is that sufficient time to safely shut down the system during a power outage? Secondly, with three 4090s, known for their high current spikes, I’d likely need a single 3kVA server-grade UPS from brands like APC. The cost would probably be $2,000 to $3,500, which seems quite steep.
When searching for an UPS, there are two key aspects to consider:
1. The output waveform (square wave, simulated sine wave and true/pure sine wave)
2. The design (stand-by, line-interactive and online)
From here, you can explore the distinctions between these aspects.
For more details on output waveforms, see:
https://www.kstar.com/indexproblem/17355.jhtml
And for explanations about UPS designs, visit:
https://www.eetimes.com/document.asp?doc_id=1272971
Waveform and design specifics
For PCs, a line-interactive UPS is generally sufficient because PSUs can manage the 2ms to 5ms transfer time easily.
Regarding output waveforms, true/pure sine wave UPSes are optimal. Simulated sine wave models are more affordable but not compatible with Active PFC PSUs. Running a simulated sine wave UPS with an Active PFC PSU may lead to significant problems—here’s what happens, how it occurs, and why.
How do you identify which PSUs have Active PFC and which don’t?
It’s straightforward: any PSU certified at 80+ (such as 80+ Bronze or 80+ Gold) must feature Active PFC.
What is Active PFC?
For further reading:
https://en.wikipedia.org/wiki/Power_fact...near_loads
Potential issues with simulated sine wave UPS and Active PFC PSUs
When a simulated sine wave UPS transitions to battery power, three possible outcomes arise:
1. The PC experiences an error and shuts down immediately.
2. The PC powers off abruptly.
3. The PC powers down from the UPS while remaining on.
Why does this occur?
Simulated sine wave UPSes generate a zero output during phase changes, creating a power gap. This can interrupt active PFC PSUs when switching from AC to simulated sine wave output (battery mode).
What should you do next?
As mentioned, your PC can operate using a simulated sine wave UPS, but be ready for possible complications. If issues emerge, consider swapping to a true/pure sine wave UPS or opting for it right away.
Power requirements
When selecting a UPS, factor in the power consumption of your PC and monitors. Don’t forget speakers, Wi-Fi routers, or other devices you plan to connect. Printers, scanners, and similar equipment aren’t compatible with the UPS as they draw excessive startup power, risking damage.
Recommended brands include CyberPower, TrippLite, and APC—these are currently top choices.
Keep in mind: a more powerful UPS extends how long your PC runs on battery before depletion.
Using a UPS with higher wattage offers better runtime, but be cautious—exceeding its limits can damage it. For example, a 900W simulated sine wave UPS may not function at all.
For optimal performance, consider a double-conversion or delta-conversion online UPS, which handles higher loads effectively. A server-grade unit around 4kW would suffice, though it comes with a cost of 5-10K.
Here are some suitable models:
- https://www.apc.com/us/en/product/S...-n...se-to-120/
- https://www.amazon.com/Rockstone-5000-Wa...00J0CF8W4/
These options provide adequate capacity, though a step-up transformer may be necessary depending on your input voltage requirements.
Thanks a lot for the information
@Misgar
@Aeacus
really appreciate it! Prices are scary!!
Damn, I was searching for 3000va at first and was a bit shocked on the price lol, and the brands I looked where like 1500 usd. Already spent 14k on this machine
😕
Another question regarding amperes, I have 0 clue but been talking with my brother and reading forums,
I live in a old apartment and saw the thermal, I have 5 switchs:
15 amp
20 amp
20 amp
20 amp
20 amp
This will be low for my current setup right? according my math it should be around 25/30 use in full load? or more? should I try to avoid using the new rig until I move to a new apartment? (in 3 months
)
My current PC (old one now, 1 PSU of 1600 + 2 2080Ti) has been working ok here, even with air conditioner turned on, but the new rig will consume much more.
Any light on the electricity side will be helpful!
Lastly, this cable for PSU is ok?
Cablelera North American Power Cord Extension, NEMA 5-15P to C19, 6', 14 AWG, 15A, 125V (ZWACPFAC-06)
Amazon.com
Thanks!
I was planning to ask about your country, but it looks like you need the plugs. You're in a tight spot. The power cords are okay because a 1600-watt supply won't exceed 15 amps. The real issue is you need two separate 15-amp outlets for them. It's rare to find two different circuits in one room. If you connect both to the same circuit, it will trip the breaker. Even with a 20-amp circuit, you'd only get just over 2000 watts. Keep in mind that most of the power turns into heat, so unless your area is very cold, you'll likely need a lot of energy for air conditioning too.
Hey
@bill001g
Thanks for your reply. I'm in the US. Should I wait until I move to a new apartment (about 3 months) before using this baby? And should I ask the new place about the ampere settings?
I asked the person who built my rig about this and they said it's not incorrect.
Thanks!
With that investment in a PC, wouldn't you want to ensure it receives top protection? Because if you opt for a low-cost UPS, it won't safeguard your PC from the threats you're trying to avoid. On the other hand, spending too much on a UPS can lead to additional complications.
You won't be able to use your PC in your present apartment because it will trigger the power breaker. And even in your new place, you might still face similar problems.
The equipment you construct is quite advanced and not suited for everyday home use. These setups are typically found in warehouses or businesses where a reliable electricity supply is available.
Your main goal would be to try it in the kitchen. It will rely on how recently the apartment was built. Most current building regulations call for two 20-amp circuits in the kitchen area. You’d need to identify which outlets belong to which circuits.
This approach would also stop you from using many typical kitchen devices, like a basic toaster, since combining them with your server would overload the power supply. The microwave, range, and refrigerator usually have dedicated outlets, but it’s hard to confirm without testing.
If you really want to proceed, consider adjusting the power sources to 230 volts. Then you could possibly use a dryer outlet—provided you’re okay with living near a dryer.
You can politely inquire with your landlord about allowing an electrician to install a circuit. They might not be comfortable with such a setup in an apartment. Have you thought about making a down payment on a house rather than spending $14,000 on a computer?
240V is more efficient, so consider that option if feasible. Please avoid connecting your computer directly to the breaker panel; otherwise, you'll need extensive adjustments to run new power cables.
I'm happy to live in a place where I can extract 3kW from one 240V 13A main plug.
My home has multiple 30A ring main circuits, so connecting the two 1600W power supplies to nearby wall sockets in the same room would be straightforward.
I also own three 240V 45A spurs for things like immersion heaters, showers, and cookers that could be used.
From what I know, some large air conditioners in the USA operate on special dual 110V (220V) circuits. Is that accurate?