Difference between Coolermaster RS-450-ACLY and ACLX?

[puppyfriend]

I figured it out. It's the APFC. How can I delete this post?

What's the difference between the Coolermaster RS-450-ACLY and the Coolermaster RS-450-ACLX? I looked at both the spec sheets and they look exactly the same. The only thing I can see is the Y has a blue led in the fan and the X doesn't. The X is $20 cheaper though.

 

[Ice Czar]

why would you need to delete it?
someone might want tp know the same thing and actually use the search feature
slim of a chance as that is

having Active Power Factor Correction can be a major sales point if your using a UPS
when its actually on batteries they really dont like nonlinear loads, when it on the mains it doesnt really matter all that much.
might be worth the extra few shekels


cut and paste
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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.

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 an online UPS (and by extention Id assume a line interactive UPS \ SPS when its on batteries, a far more common UPS scheme)


a bit more on PFC
PFC Decoded
and on UPSs
Power Conditioning 101
DIY UPS all @ dansdata

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[[Spectre]]

There is a search feature.......next thing you will tell me is there are stickies.......lies......lies I tell you!

 

[mavalpha]

Also, the more expensive model has that nifty front load display that tells you exactly how many watts your PSU is supplying.

 

[puppyfriend]

I think they both have that.

 

[mavalpha]

Dammit, you're right. (J/K)