Offline SMPS and Conducted immunity test?

Status
Not open for further replies.
C

cupoftea

Advanced Member level 6
Joined
Jun 13, 2021
Messages
3,059
Helped
62
Reputation
124
Reaction score
139
Trophy points
63
Activity points
15,963
Hi,
We have a 17W non isolated buck running of Single diode rectifier from mains 100-265vac.
The neutral is ground for the whole circuit, and the "load" circuitry.
There is no impedance in this neutral net, at all, anywhere.
So, Will this fail conducted immunity compliance testing?
 

Sort by date Sort by votes
To put it another way....Can a Half wave rectified offline SMPS pass conducted immunity, when it has no impedance in its ground net? (And the ground net is Neutral)
 

Upvote 0 Downvote
Thanks, may i ask what standard that comes from at all?...is it the EN62368?
 

Upvote 0 Downvote
your smps appears not to pass the < 5mA DC in the neutral requirement to prevent earth stake corrosion
Click to expand...
Thanks, ayk, thats by dint of the fact that its half wave rectified...but the following...

EN 61000‒3‒2:2014

rfemcdevelopment.eu

..states that if equipment is <100W active power, then its OK to use half wave rectification.
 

Upvote 0 Downvote
most countries have their own standards for DC limits on equipment - as too much DC can cause fuses to trip on supply transformers - and of course CT's will not work properly - as well as earth stake corrosion associated with houses and buildings.

In NZ & Australia & the UK & Canada it is < 5mA ave for any 24 hr period
 
Last edited:
Upvote 0 Downvote
Thanks, i see what you mean, though ayk, with the CT's, the safety ones are the RCD type ones, and they dont mind DC as long as it flows in the Line and then out in the neatral.....as it balances out then...and the fields cancel.
 

Upvote 0 Downvote
Nothing said about RCD, they are in fact unrelated.

I'm still interested to know which standards are addressing the topic. 61010-3-2 is obviously allowing higher DC current.
 
Upvote 0 Downvote
Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…