We use a Yokogawa 3226 Universal Leakage Current Tester together with a 3227 Test Box. The meter has both an "AC" and an "AC+DC" current range, and switchable 1K, 1.5K, and 2K input resistance. The test box has a polarity and an on-off switch to simplify testing, and has a US mains socket into which we plug the product to be tested, using a cord with the earth pin cut off, which we can also readily reverse. UL and CSA seem quite happy to use this meter when they come here to review our products. We also have a Simpson 229-2 which is there to be used if the other meter is being calibarated, and it gives similar results to the Yokogawa. I asked UL to bring their Simson 228 meter here during a recent investigation, to compare results. It read a little higher than the Yokogawa, but UL were happy for us to continue using the Yokowawa. They certainly do not insist on the use of the Simpson 228.
I had some information on a Hioki Model 3155-01 Leakage Current Tester, which is claimed to meet the latest IEC 950 requirements, but I can't readily lay my hands on it. IT WAS EXPENSIVE. It is a digital meter, could also measure the voltage/current going to the equipment, and had pluggable networks for 950 and medical equipment measurements. >From time to time when I am doing leakage current measurements, I check that the results I get ARE VERY SIMILAR to the reading I get if I just put the meter in series with the ground conductor of the product. (And they are always almost identical) Could somebody explain why this much simpler method is not used ? John Crabb, Development Excellence (Product Safety) , NCR Financial Solutions Group Ltd., Kingsway West, Dundee, Scotland. DD2 3XX E-Mail :[email protected] Tel: +44 (0)1382-592289 (direct ). Fax +44 (0)1382-622243. VoicePlus 6-341-2289. --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
