Typically, the rated voltage is the nominal voltage, which means that high lines are okay. There are other ratings for circuit breakers, however, such as interrupting current. We use a breaker rated for single phase line voltage (100V, 120V, 230V). but it has a interrupting capacity of 10,000 symmetrical A. Regards, Brian Epstein Sr Regulatory Compliance Engineer Veeco Instruments [email protected] ph (805) 967-2700 ext 2315 fx (805) 967-7717
From: POWELL, DOUG [mailto:[email protected]] Sent: Friday 07 May 2004 11:11 AM To: [email protected] Subject: Circuit Breaker Rating All, I would like to find out how circuit breakers are rated for line voltage. I'm certain I know the answer but I need some collaborating information for a colleague. If I have a 250V per phase rated breaker, does this mean that I can use it on mains up to 250V without regard to 10% high and low line, or is this an absolute maximum? For example: In a 3ph system of 230/400Vac the 10% high line is 253/440Vac. Is this okay? Or, theoretically: If were such a utility in the world, at 250/433Vac the 10% high line would be 275/476Vac. Is this okay? thanks, -doug Douglas E. Powell, Staff Engineer Corporate Compliance Dept. Advanced Energy Industries, Inc. Fort Collins, CO 80525 USA
