From: treg@world.std.com@INTERNET on Fri, May 9, 1997 9:48 AM
Subject: RE: IEC 950 / UL 1950 creepage and clearance requirements
>You need to be careful when considering the working voltage between TNV and
>SELV. For the US, you can use the method outlined by Richard. However,
for >
: treg@world.std.com
Subject:Re: IEC 950 / UL 1950 creepage and clearance requirements
Joe Finlayson wrote:
>
> To any and all safety gurus,
>
> I am in the midst of trying to minimize the creepage and clearance
> requirements between TNV and SELV called out
Joe Finlayson wrote:
>
> To any and all safety gurus,
>
> I am in the midst of trying to minimize the creepage and clearance
> requirements between TNV and SELV called out in IEC 950. My
> interpretation of tables 5 and 6 in sections 2.9.2. and 2.9.3 are that
> minimu
Joe,
Under table 6 look at note 4. "Where the material group is not known,
material group IIIb shall be assumed."
Best regards,
Stephen C. Phillips
At 03:01 PM 5/8/97 -0400, you wrote:
> To any and all safety gurus,
>
>I am in the midst of trying to minimize the creepa
Joe,
If you use Amendment 4 of IEC 950, and fall into the TNV-1 category, you can
use operational insulation and a dielectric test between SELV and TNV. Of
course amendment 4 is not universally accepted (i.e. Australia), but UL will
allow the TNV 1 conditions when evaluating to UL-1950 3rd Ed
Hello Joe:
Note 3 of table 6 refers to IEC 112 for the method of testing CTI to determine
material groups for this table. CTI refers to "Comparative Tracking Index"
which is a measure of how well a material resists tracking. What happens, is,
given a high enough potential applied for enough ti
