2009/1/6 Xiaofan Chen : > On Tue, Jan 6, 2009 at 7:37 AM, Forrest W. Christian wrote: >> I'm looking for what the minimum clearances are for traces on a circuit >> board which will carry 120 or 240VAC. This is essentially for the >> relay contacts which may be field wired to either 120 or 240V. >> > > This will depend on the device and the standards applied. > Different standards will have different requirement. > > Xiaofan > -- Operating altitude can come into it also. IIRC we used to use 3.2mm in our applications (telecom power supplies) but this increased to 4.5mm when we started looking at operation at heights in excess of 2000m. I could be wrong though - I'm on holiday and all "that stuff" is a bit blurred. RP -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist