From: Paul Lovell - Telco Platforms Group <[email protected]> Subject: Re: More on Creepage and Clearances
Richard, Maybe the Committee Secretaries/Chairmen could explain this curious state of affairs. Paul Lovell@SunUK > Date: Wed, 24 Sep 1997 11:33:23 +0100 > From: Richard Steele <[email protected]> > Mime-Version: 1.0 > To: [email protected] > Subject: More on Creepage and Clearances > Content-Transfer-Encoding: 7bit > > Treggers, > > Can anyone tell me where the Creepage distances "on printed wiring > board, NOT coated" and Clearances quoted in EN 61010-1 Annex D are > derived from? > > EN 61010-1 quotes the source as IEC 664-1 but comparing the figures they > don't tie up i.e > > Circuit type - Secondary > Working voltage - 100V > Pollution degree - 2 > Overvoltage Category - 1 (1.5kV) > CTI - 200 (material group IIIa) > Insulation - Operational or Basic > > IEC 664-1 > Creepage - 0.16mm (table 4) > Clearance - 0.5mm Inhomogeneous field 1.5kV impulse (table 2) > - 0.3mm homogeneous field 1.5kV impulse (table 2) > > EN 61010-1 > Creepage - 0.2mm (table D.2) > Clearance - 0.2mm (table D.2) > > and just to completely confuse matters, > > EN 60950/A4 > Creepage - 1.4mm (table 6) > Clearance - 0.7mm (table 5) > > The creepage distances given for "In Equipment" are the same between all > 3 specs! > > Which is correct and why? > > > Please, please give me some feedback as this is driving me to despair. > > > Richard
