Important Announcement: Community Back to Full Functionality
Dear Members, we are thrilled to announce that our Community is back to full functionality and that posts publication is now enabled again! We appreciate your patience during the last weeks. Learn more about our Community Guidelines. Thank you, Schneider Electric Community Team.
Metering & Power Quality
Schneider Electric support forum about Power Meters (ION, PowerTag, PowerLogic) and Power Quality from design, implementation to troubleshooting and more.
Link copied. Please paste this link to share this article on your social media post.
Hi,
Can someone explain to me how bad this figure is for ATHDF%...using a Tektronix power meter PA1000 to characterise a power adapter 230VAC to 5Vdc. The power adapter has a rating of 5V output, max 1A. When loaded at max 1A, the power meter provides a power factor reading of 0.427 and ATHDF% of 154. I'm having difficulty interpreting 154 for THDF(current). 154% looks bad but is it normal for these cheap type switching PSUs? At 25% load or 250mA the reading increases to 163%.
Thanks
Link copied. Please paste this link to share this article on your social media post.
I'm not familiar with the term "ATHDF%" nor the "Tektronix power meter PA1000", but if I had to guess this is the "Amps Total Harmonic Distortion as a % of Fundamental".
Yes, >100% current distortion as a % of fundamental is very typical for all switch-mode power supplies without active PFC. Normally for most loads <50W, load current THD is not a concern.
Link copied. Please paste this link to share this article on your social media post.
I'm not familiar with the term "ATHDF%" nor the "Tektronix power meter PA1000", but if I had to guess this is the "Amps Total Harmonic Distortion as a % of Fundamental".
Yes, >100% current distortion as a % of fundamental is very typical for all switch-mode power supplies without active PFC. Normally for most loads <50W, load current THD is not a concern.
Link copied. Please paste this link to share this article on your social media post.
Great, thanks for the reply. Yes, your guess of the acronym ATHDF% is correct.
Create your free account or log in to subscribe to the forum - and gain access to more than 10,000+ support articles along with insights from experts and peers.