Class 2 power supply internal ground connection

18 4

Reply | New topic

#1 21675836 03 May 2016 22:54

Cullen Combs Cullen Combs

Anonymous

Post #1
21675836 03 May 2016 22:54

I am curious about ground connections used on a class 2 AC adaptor. The power supply has a three wire grounded cord end however the ground wire is simply cut off inside the enclosure of the power supply. I have attached an image of the power supply with the plastic enclosure removed. This power supply is UL listed. I am curious if this is acceptable and if it breaks any UL or other related codes.
ADVERTISEMENT
#2 21675837 04 May 2016 01:58

richard gabric richard gabric

Anonymous

Post #2
21675837 04 May 2016 01:58

If the case is plastic, and the transformer has adequately rated insulation between primary and secondary, then it should meet the spec, and a ground should not be used.
Depending on the point of origin, the UL listing may be faked, but that should be check-able,
cheers,
Richard
ADVERTISEMENT
#3 21675838 04 May 2016 03:19

Cullen Combs Cullen Combs

Anonymous

Post #3
21675838 04 May 2016 03:19

Thanks for the reply. I was curious why they would use a three conductor cord in place of a two conductor and polarized plug. I kinda thought maybe they was trying to make it look like it was a grounded circuit when in reality it isn't.

I was able to lookup the UL listing number and found that the model I have is not listed on the UL reference.
ADVERTISEMENT
#4 21675839 04 May 2016 12:50

richard gabric richard gabric

Anonymous

Post #4
21675839 04 May 2016 12:50

A legit unit made in volume would only have a two wire cord. If you are a cut price manufacturer, and have a three wire cord lying around in large quantities, then it makes sense to cut the earth wire out, call it taking a short cut,
cheers,
Richard
#5 21675840 04 May 2016 22:36

richard gabric richard gabric

Anonymous

Post #5
21675840 04 May 2016 22:36

See this link,

http://www.edn.com/design/pc-board/4441830/Te...ebdb&elqaid=32087&elqat=1&elqCampaignId=28003

cheers,
Richard
Create an account, log in here. You will receive points by participating in discussions.
Join this discussion.

Install Elektroda application

Didn't find an answer? Ask Artificial Intelligence

*I agree to send the question to OpenAI, Anthropic PBC, Perplexity AI, Inc., Kagi Inc., Google LLC - owners of language models in order to prepare the best response. The companies may monitor and log information entered into the form.

*I agree to publicly display my question and answer. The question and answer will be publicly available to everyone. The process may take a few minutes. Upon completion, you will be redirected to the page with the answer.

Wait...(2min)

Reply | New topic

Report a violation of the law

Home page
/
Forum
/
Circuit Design
/
EEWeb Topics
/
Class 2 power supply internal ground connection

Class 2 power supply internal ground connection

Didn't find an answer? Ask Artificial Intelligence