It’s been a few years, but I seem to recall there was a particular IEC/EN 60335-2-xx standard that required tubular sheathed heaters to be grounded. This would force PE to be brought in.
Additionally, IEC 60335-2-38 and IEC 60335-2-75 have requirements for Equipotential grounding. If I remember correctly IEC 60335-2-75 does not allow Class II products. Josh Joshua Wiseman Systems Engineering Staff Engineer, Product Safety/EMC Ortho Clinical Diagnostics [https://insideortho.orthoclinicaldiagnostics.global/wps/wcm/myconnect/add13339-9211-4e73-9f5d-229f45406f61/OrthoMailSigLogo160x17.png?MOD=AJPERES&CACHEID=ROOTWORKSPACE-add13339-9211-4e73-9f5d-229f45406f61-mm1LfFj] From: Richard Nute <[email protected]> Sent: Tuesday, January 14, 2020 2:38 PM To: [email protected] Subject: Re: [PSES] Class I vs Class II safety constructions EXTERNAL SENDER: Verify links, attachments and sender before taking action Hi Scott: I have seen no safety standards or codes that specify which products must be Class I and which products must be Class II, except in the USA washers and dryers must be Class I. As far as I know, the decision is that of the manufacturer. I have been associated with a manufacturer who has made the same product both ways. In my case, one of the factors in deciding Class I or Class II was cost (e.g., a 3-wire cord was more expensive than a 2-wire cord). I suspect a major factor is “momentum” of the manufacturer: we made it this way last time, and we know how to do it this way. A product with a grounding (3-wire) power cord is a Class I product regardless whether it has no accessible conductive parts. Unlike a Class II product, a Class I product does not bear a marking attesting that it is Class I. Note that a Class I construction necessarily includes Class II construction, e.g., appliance inlet which is all-insulated. We ignore the Class II construction portions of a Class I product. I checked our electric kettle (which has accessible metal) and electric coffee-maker (which has the heater plate accessible metal). Both are 2-wire. Neither has the double-insulated symbol. Both are UL-certified. Best regards from beautiful snowy Bend, Oregon, USA, Rich From: Scott Xe <[email protected]<mailto:[email protected]>> Sent: Tuesday, January 14, 2020 6:59 AM To: [email protected]<mailto:[email protected]> Subject: [PSES] Class I vs Class II safety constructions In terms of safety level, both constructions are given the equivalent protection against electric shock. In electrical appliances, Class I is used most whereas Class II is employed in most electronic products. Is there any background for such design route? In some cases such as induction cookers, the enclosure is plastic/glass - no any internal metal part exposes to the outside surfaces. The product is not marked with a double square symbol and comes with a 3-pin plug. Why is this type of product not classified as Class II rather than Class I with the plastic/glass enclosure? Thanks and regards, Scott - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]<mailto:[email protected]>> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html<https://nam03.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.ieee-pses.org%2Femc-pstc.html&data=02%7C01%7Cjoshua.wiseman%40orthoclinicaldiagnostics.com%7Cdc0b67f74a034aa070d408d7992960f4%7C6e63ffc0c2fc4cc4b6c4666b2ce89d92%7C0%7C0%7C637146275311092978&sdata=VK6cuL7ePU6oDt9v8NO51EwQSKvB%2BNGBg%2BL9dGQKeQg%3D&reserved=0> Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/<https://nam03.safelinks.protection.outlook.com/?url=http%3A%2F%2Fproduct-compliance.oc.ieee.org%2F&data=02%7C01%7Cjoshua.wiseman%40orthoclinicaldiagnostics.com%7Cdc0b67f74a034aa070d408d7992960f4%7C6e63ffc0c2fc4cc4b6c4666b2ce89d92%7C0%7C0%7C637146275311102973&sdata=tTm7bZFPxH4NnpLtIajYIg%2BjSATXrEMT0CXEB2GEjVY%3D&reserved=0> can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/<https://nam03.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.ieee-pses.org%2F&data=02%7C01%7Cjoshua.wiseman%40orthoclinicaldiagnostics.com%7Cdc0b67f74a034aa070d408d7992960f4%7C6e63ffc0c2fc4cc4b6c4666b2ce89d92%7C0%7C0%7C637146275311102973&sdata=1Cks2AVJbk4jqm9FOW5idAKSnNh838XMj68RbFKj%2F1M%3D&reserved=0> Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe)<https://nam03.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.ieee-pses.org%2Flist.html&data=02%7C01%7Cjoshua.wiseman%40orthoclinicaldiagnostics.com%7Cdc0b67f74a034aa070d408d7992960f4%7C6e63ffc0c2fc4cc4b6c4666b2ce89d92%7C0%7C0%7C637146275311112963&sdata=5N8f6hny6GeFpStI6ZumH53IIsePTAY%2FCZZzsY3tbG8%3D&reserved=0> List rules: http://www.ieee-pses.org/listrules.html<https://nam03.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.ieee-pses.org%2Flistrules.html&data=02%7C01%7Cjoshua.wiseman%40orthoclinicaldiagnostics.com%7Cdc0b67f74a034aa070d408d7992960f4%7C6e63ffc0c2fc4cc4b6c4666b2ce89d92%7C0%7C0%7C637146275311112963&sdata=1zZD9%2BWJS70fOforGFNUQ08oZhI0uHZgrPCodRUqI%2F8%3D&reserved=0> For help, send mail to the list administrators: Scott Douglas <[email protected]<mailto:[email protected]>> Mike Cantwell <[email protected]<mailto:[email protected]>> For policy questions, send mail to: Jim Bacher <[email protected]<mailto:[email protected]>> David Heald <[email protected]<mailto:[email protected]>> - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
