If an offline power supply is drawing 2W of power virtually all the time, then why does it need PFC?
I am working in a project consultancy doing work with an electronics contractor, ultimately for a big customer.
The consultancy is making an offline 240VAC SMPS which after being installed, will firstly charge up a 24V battery at 5A for 3 hours. Then it will simply sit there for the next 10 years drawing about 2W of standby power, as the equipment continuously monitors some safety valves which should be actuated in case of emergency. The 24V battery also needs to be kept topped up with a “float” charge, but this is only part of the 2W standby power.
As such, is there some clause in the EN61000-3-2 standard which we can invoke in order for us to avoid using a PFC stage?
I mean, our average power draw is so low that surely a PFC stage would not be mandated for this?
A PFC stage, for 3 hours of useage above 75W in 10 years doesnt make sense?
Surely some clause in the regs exists saying that a simple offline SMPS can be used here?....ie no PFC front end?