So I have a 500W Active PFC Power Supply for my home PC (and it probably is not pulling anything close to that... I only have 1 graphics card and one HDD (and one SSD))
APC has a document about active PFC and power supplies in which they explain the issues with using simulated sine wave UPS's... then they say
It is important to note that not all PFC power supplies will cause the UPS overload. However, the incompatibility is most acute
in the one of the following situations:
• A large server class PFC supply (e.g. rated 500W or more) is used with a Back-UPS or Smart-UPS SC.
so 500W is the very bottom limit... And the say...
APC recommends that a true, pure sine wave, server class UPS be used..... ...However if, a [non-pure/simulated/stepped sine wave UPS like] Smart-UPS SC or Back-UPS RS is to be used, the UPS should be sized accordingly.
So my question is... does anyone know what "sized accordingly" means? Because its probably WAY cheaper for me to buy an overpowered simulated sine wave UPS than a properly powered pure sine wave UPS. But I don't know how overpowered it must be...
I think the most relevant quote in terms of what might happen is...
Because of the way active PFC’s operate, they can sometimes overload the UPS with momentary high inrush current. This can occur when the UPS transfers from online to on-battery operation, creating a momentary loss of power (<8ms). The PFC supply may respond by temporarily drawing an excessive amount of current.
So the question basically becomes... how much extra wattage could a 500W PSU pull with a "momentary high inrush current" trying to compensate for a 8ms power loss?
Anyone know the answer?