That is the formula for the geometric sum of 2 RMS quantities. For example, if you have a primary circuit that has a working voltage of 230Vrms and a secondary circuit with a working voltage of 32Vdc, the RMS working voltage BETWEEN the two circuits is determined with the formula, giving you 232Vrms as a figure to use for creepage determination. Measuring the actual RMS voltage is preferred, once you have a sample, but be careful to do a worst-case grounding connection from one circuit to the other or you won't get a meaningful or worst-case voltage measurement. I use the formula early in design, and then measure later. Jim Eichner, P.Eng. Compliance Engineering Manager Xantrex Technology Inc. e-mail: [email protected] web: www.xantrex.com Any opinions expressed are purely accidental. Confidentiality Notice: This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message.
From: Brian O'Connell [mailto:[email protected]] Sent: Thursday, December 18, 2003 7:50 AM To: [email protected] Subject: Good People What is the basis of this formula for working voltage ? sqroot(a^2 + b^2) thanks, Brian
