Document: NUREG-0800
Document ID: 97120913-d26f-4324-ab62-22f3f5b73925
Document Type: srp
Title: and 8.3.2.
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0636/ML063600410.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.3.1
CFR Part: 
CFR Title: 

Content:
chyard circuit breakers must then be reclosed to establish offsite power to the unit. A generator circuit breaker, however, could interrupt the fault current and isolate the unit generator at the same time, maintaining continuous power to the onsite ac power system. IEEE Std. C37-013 (Reference K) was issued to cover the ratings and required capabilities for ac high-voltage generator circuit breakers rated on a symmetrical current basis that are installed between the generator and the transformer terminals. Guidance for the application of generator circuit breakers is also given. 2. Specific Guidelines A. Only devices which have maximum fault current interrupting capability, i.e., circuit breakers, can be used to isolate the unit generator from the offsite and onsite ac power systems in order to provide immediate access for the onsite ac power system to the offsite source. Generator load break switches can only be used for isolating the unit generator for the purpose of providing a delayed access offsite source. B. Generator circuit breakers should be designed to perform their intended function during steady-state operation, power system transients and major faults. The ratings and required capabilities of a generator circuit breaker are the designated 8.2-31 Revision 4 - March 2007 limits of operating characteristics based on definite conditions as defined in IEEE Std C37.013 (Reference K). This standard describes design test procedures and methods that should be performed to demonstrate the ability of a generator circuit breaker to meet the assigned ratings when operating at rated maximum voltage and power frequency. As a minimum, the following performance tests and capabilities from IEEE Std C37.013 should be demonstrated: (i) Rated Dielectric Strength. The dielectric strength of a generator circuit breaker should be demonstrated by subjecting it to high voltages, both rated power frequency withstand voltage and rated full wave impulse withstand voltage based on