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Is Active PFC worth the extra $$?

its not a prime consideration in a purchasing decision
if your in the US

it can benefit some more esoteric UPS schemes (ferroresonant transformers \ Ferrups)
 
My Enermax 3 in 1 says it has no PFC. I'm on 230v here in New Zealand now and its running off a SmartUPS 620VA/390W line interactive UPS. Is having no PFC a bad thing?
 
hmmm...been doing a bit more research

Power Supply System Integration Part 2: Battery Backup @ Power Electronics Technology

UPS Nonlinear Loads

Most end users are oblivious to the problems encountered when an online UPS interacts with nonlinear load, such as a switchmode power supply. Fig. 3, on page 42, illustrates the interface between an online UPS and a switchmode power supply. The switchmode supply within the host system consumes its current in high amplitude pulses, and as a result overloads the UPS, distorts its output and degrades in performance. This isn't the case if the SMPS has power factor correction (PFC); and in the United States most SMPS don't have PFC.

Repeated measurements under practical conditions show that in non-PFC SMPS, the current peak to rms ratio reaches a crest factor in the range of 2.5 to 3.5. This high crest factor imposes a difficult load for the UPS.

Manufacturers specify UPS capacity in volt-amperes, and set the UPS current limit with resistive loading. This affects the user in two ways: first, the actual power (in watts) that the online UPS can deliver is 75% to 80% of its VA rating. Second, the UPS cannot support a nonlinear load like a SMPS to full power capacity. In fact, it can support an SMPS only rated to 30% to 40% of its capacity. A 1kVA online UPS will only be suitable for backing up a system energized by a 300W to 400W (non-PFC) switchmode power supply. Attempts to draw higher power by the SMPS will severely distort the output of the UPS and may result in shutdown. Some UPSs support nonlinear loads to various degrees, but the above rule is safe to use as a guideline.

The whole idea of generating a high-purity sinewave within the UPS, and then rectifying it within the SMPS is wasteful. A UPS may be deployed to run non-electronic loads, such as lights or motors. However, this is a minor portion of the market for online UPS. Many applications back up computers and telecom devices, as well as instrumentation systems used for critical applications. In all of these applications, the immediate load for the UPS is the SMPS within the systems. Peak current and inrush current are associated with this load at startup. This current of 40A to 80A per SMPS will cause the UPS to shutdown due to overloading, or the UPS must transfer the load to utility to draw its inrush.
Click to expand...

Im "upgrading" the importance of active PFC in purchasing, as it does seem to have a great deal to do with not abusing and effectively employing the capacity of a line interactive UPS
 
BossNoodleKaboodle said:
My Enermax 3 in 1 says it has no PFC. I'm on 230v here in New Zealand
Click to expand...

you sure?
PFC is required most places outside the US
it might have it, but not be listed as having it since its a "moot" sales point
Id double check that ;)
 
ahh well if you bought it here its very likely not PFC
from what I gather the way it draws power from a UPS limits the ability of the UPS to "be all it can be"
meaning you need a much larger UPS (KVA) than if it was a PFC supply

In fact, it can support an SMPS only rated to 30% to 40% of its capacity. A 1kVA online UPS will only be suitable for backing up a system energized by a 300W to 400W (non-PFC) switchmode power supply
Click to expand...

so thats for an "online" UPS not an interactive one, but I would gather that if or when your line interactive UPS kicks over to the batteries, that will be an issue as well

Im going to get gee's take on this
 
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