Well, What's legal?
What's smart? What gets by unnoticed? What is practical? What's legal: If a product is Class 1 (needs Earth Ground) then legally it needs to have its ground conductor plugged in. That's regardless of if it's the US, UK, U(anywhere). I say "legally" in the sense that you are violating UL, OSHA, (the authority having jurisdiction) the manufacturer's instructions... The penalty depends upon who inspects your facility. It also depends on who you are. For instance, we unground oscilloscopes on a regular basis when conducting noise measurements on sensitive circuitry. But, we're engineers, we know the risks. We do it of our own free will. We are "professionals" trained to deal with risks that the general public shouldn't be exposed to. What's smart: It's always smart to ground Class 1 equipment. I have a feeling that "hum" could be solved by power filtering without disconnecting grounds; the ground removal is probably just an easy way out. What gets by unnoticed: You may have heard about buildings with no ground because there are a ton of them here in the states. Many of them go unnoticed because the Authority having Jurisdiction hasn't had an excuse to inspect them. For instance, my own house is almost entirely ungrounded; I don't get any greif because it hasn't changed ownership (no mortgage loan inspection) and it hasn't been remodeled (no building permits applied for)...so it hasn't been inspected. Theoretically, I could put a professional audio system in my house without grounding it and nobody would know. OSHA wouldn't inspect it because I'm not an employer. ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
