SMPS with PFC?

[schnell]

We are in Maryland and we have an SMPS which is rated at 60W, and therefore it has a PFC front end.

However, the 60W output only occurs for one second when 4 solonoids are operated.

-after that, the power draw never goes above 30W.

Its in a shower unit so the (normally-closed) solonoids only get activated once per day, per person, typically.
-after being activated, the solonoids draw the low level holding current.

-so should we really need the PFC stage?

 

[rcw retired EE]

What is SMPS? PFC = Power Factor Control? Why does a 60W load draw make it have power factor control? Interesting.

 

[ScottyUK]

SMPS = switch-mode power supply. Correct on PFC.


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If we learn from our mistakes I'm getting a great education!

 

[itsmoked]

No you shouldn't really need PFC however, "rules" may dictate it. That can happen when a location could have a bunch of something that will add up in power line harmonics. For instance it's possible for a facility to have several hundred PCs. Each may only draw a small amount that would normally not amount to any bothersome harmonics, but with hundreds, the harmonic can increase to a point that causes a lot of electrical problems with other equipment, the facility, or the utility.

So, we can't definitively say no you don't need PFC.

Keith Cress
kcress -

http://www.flaminsystems.com