Hi, I did some intensive investigations on this issue, but the results are in German.
You should have no problem if the power line system is TN with earthed central point. In this case the voltage of each outer conductor to earth is U/sqrt(3), in your case 208V/sqrt(3). In an IT power line system, there always is an insulation monitoring system, which is connected between earth and one of the outer conductors (e.g. L3). This means that this conductor (L3) is earthed over a relatively high impedance (1K). The voltages of the of the other two conductors to earth would be 208V. This is also the voltage across the Y capacitors in the power line filters. They are usually rated for 250V or 275V. That means you will have no problems, with the exception of a higher leakage current. You would have problems in a network with a higher voltage (e.g. 400V/230V), even if you connect the consumer between an outer conductor (phase) an the neutral, because the the voltage of the outer conductor to earth would be 400V in this case. Y capacitors are not rated for 400V. Hope this helps. Best regards George [email protected] wrote: > My company manufactures systems which incorporate power supplies from > various manufactures. Typically these supplies have ratings such as > 100V-140V/200V-240V and are designed to operate on a single phase > input. > Some of my customers have the US 208V 3 phase power distribution which > > gives you 208V phase to phase or 120V phase to neutral. > > My question is directed towards the power supply people on this list. > > Can ANY supply intended for 200-240V single phase be used at 208V > phase > to phase (double phase). Would components (EMI suppression for > example) > be placed between neutral and ground that would preclude the supply > from being used phase to phase? > > Would the use of these supplies in a phase to phase mode negate the > EMI/EMC performance? > > Thanks > > --------- > This message is coming from the emc-pstc discussion list. > To cancel your subscription, send mail to [email protected] > with the single line: "unsubscribe emc-pstc" (without the > quotes). For help, send mail to [email protected], > [email protected], [email protected], or > [email protected] (the list administrators). -- ************************************************************** * Dr. Georg M. Dancau * HAUNI MASCHINENBAU AG * * [email protected] * Manager EMC Lab * * TEL: +49 40 7250 2102 * Kampchaussee 8..32 * * FAX: +49 40 7250 3801 * 21027 Hamburg, Germany * ************************************************************** * home: Tel: +49 4122 99451 * Hauptstr. 60a * * Fax: +49 4122 99454 * 25492 Heist, Germany * ************************************************************** --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
