What did you use for the 200A source ? thnx, another Brian
> -----Original Message----- > From: [email protected] [mailto:[email protected]]On Behalf Of Tarver, > Peter > Sent: Monday, February 05, 2007 10:23 AM > To: emc-pstc > Subject: RE: Protective Earth through PCB traces > > > Brian - > > Aside from current carrying capacity of copper, the presence of solder > is a concern. > > CSA/UL 60950-1 have requirements to test against for such > constructions. > These requirements are based on CSA 22.2 No. 0.4 (Limited > Short-Circuit > Test). Test fault current simulation is based on branch circuit > protection sizes and input current rating, with the > compliance criteria > including successfully opening the branch circuit protection without > degradation of the earthing circuit impedance beyond a small > percentage. > > I have performed around six to ten of these tests at the 200 A level. > In each case, the circuit breaker I used opened in less than half a > cycle. I have experienced no noncompliances. In fact, the earthing > impedance _improved_ after the fault condition was imposed. > > I do not recall the copper weights or trace widths for these products, > but they were rated for less than 4.9 A at 240 V. > > The next higher step in assumed fault current is 1,000 A. > > > Regards, > > Peter L. Tarver, PE > [email protected] > > > > > From: Brian Kunde > > Sent: Monday, February 05, 2007 6:49 AM > > > > There was an article in one of the many trade magazines we get a few > > years back about running PE or Safety Earth ground traces > on a PCB and > > how they needed to be designed so not to get damaged during > a short or > > overcurrent situation. I can't find this article so if > anyone help me > > out I appreciated it. > > > > We are using a "Distribution Card" to power AC sub assemblies in our > > product. So we want the PE traces in this distribution card > to handle > > the fault current without damage. The sub assemblies have a fault > > current in the 5 to 10 amp range depending on the assembly. > > > > Our CAD guys just want a current value for the PE so they can > > plug into > > their computer and it will make the trace width wide enough > to handle > > the current. So is X2 the fault current enough? I thought the > > article I > > mentioned above recommended X3 or X4. > > > > Appreciate any recommendations. > > > > The Other Brian. > > > > CONFIDENTIALITY > This e-mail message and any attachments thereto, is intended > only for use by the addressee(s) named herein and may contain > legally privileged and/or confidential information. If you > are not the intended recipient of this e-mail message, you > are hereby notified that any dissemination, distribution or > copying of this e-mail message, and any attachments thereto, > is strictly prohibited. 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