Re: [PSES] insulation between SELV and protective earthed accessible part- IEC 62052-31

-dmarc-requ...@ieee.org>> *Sent:* Tuesday, March 13, 2018 8:57 AM *To:* EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> *Subject:* Re: [PSES] insulation between SELV and protective earthed accessible part- IEC 62052-31 Hi Vyas, I'm not familiar with this standar

Re: [PSES] insulation between SELV and protective earthed accessible part- IEC 62052-31

...@woodjohn.uk] Sent: 14 March 2018 00:58 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] insulation between SELV and protective earthed accessible part- IEC 62052-31 I agree: SELV as a low-voltage earth-free supply is not actually a safe concept. It's OK for short connections in the same space

Re: [PSES] insulation between SELV and protective earthed accessible part- IEC 62052-31

ubject:* Re: [PSES] insulation between SELV and protective earthed accessible part- IEC 62052-31 Hi Vyas, I'm not familiar with this standard, but the general principle is that 2 levels of protection are required to protect operators from hazards. In the case of the "protective earthed acce

Re: [PSES] insulation between SELV and protective earthed accessible part- IEC 62052-31

: Scott Aldous <0220f70c299a-dmarc-requ...@ieee.org<mailto:0220f70c299a-dmarc-requ...@ieee.org>> Sent: Tuesday, March 13, 2018 8:57 AM To: EMC-PSTC@LISTSERV.IEEE.ORG<mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: Re: [PSES] insulation between SELV and protective earthed accessibl

Re: [PSES] insulation between SELV and protective earthed accessible part- IEC 62052-31

I agree:  SELV as a low-voltage earth-free supply is not actually a safe concept. It's OK for short connections in the same space, because the probability of 'power cross' is extremely remote. But if SELV is extended into several spaces, including, for example, a void, the chance of

Re: [PSES] insulation between SELV and protective earthed accessible part- IEC 62052-31

Dear Mr. Vyas: I suggest you review the definitions for SELV and PELV in IEC 62052. These definitions are not the same throughout IEC standards. (I don’t have IEC 62052.) In some standards, SELV is isolated from protective earth, and PELV is connected to protective earth. If these

Re: [PSES] insulation between SELV and protective earthed accessible part- IEC 62052-31

Hi Vyas, I'm not familiar with this standard, but the general principle is that 2 levels of protection are required to protect operators from hazards. In the case of the "protective earthed accessible part", I imagine the standard assumes that a single fault could compromise the protective