IEEE Std 741-2017 pdf download – IEEE Standard for Criteria for the Protection of Class 1 E Power Systems and Equipment in Nuclear Power Generating Stations.
5.1 .3 Feeder circuit s For recommended practice on motor protection , refer to IEEE Std C37.96 , IEEE Std 242 , and IEEE Std 666 See clause 5.5 ofthis standard for additional associated motors (VAMs). The feeder circuit protection shall consider any expected operating conditions ofthe motor that could require cur- rent demands above the motor’s nameplate rating such as operation into the motor service factor (see NEMA MG 1-2014) , For recommended practice on power transformer protection , refer to IEEE Std C37.91 and IEEE Std 666. For recommended practice on feeder circuit to power distribution panel protection , refer to IEEE Std and IEEE Std 242. For criteria on isolation and separation of 1 E circuits from Class 1 E circuits , refer to IEEE Std 384. For use ofhigh-speed magnetic circuit breakers in special applications , refer to Annex D. 5.1 .4 5tandby power supply protection For diesel generator protection recommended practice , refer to IEEE Std 242 ln the manual control mode , synchronizing interlocks should be provided to prevent incorrect synchronization whenever a standby power SOllrce is required to operate in parallel with the preferred power supply When a standby power supply is being operated in para ll el with the power shall be provided to separate the two suppl ies if either becomes degraded to an llnacceptable leve l. This protection shall not lock out or prevent the availability ofthe power supply that is not degraded 5.1 .5 Lo ad shedding and sequentialloading An automatic load shedding and sequential loading scheme may be included to enSllre that the preferred or standby power SOllrces can be loaded while maintaining voltage and frequency within acceptable Ii mits The Class I E bus load shedding scheme shall automatically prevent shedding dllring sequencing ofthe emer- gency loads to the bus when connected to the standby power source.