GE HAA relays in sudden-pressure applications

Picture of GE HAA 16B relay

Fault-pressure relays protect transformers from internal electrical faults that other protective relays, like differential or overcurrent, can’t always detect. If the transformer’s protective relaying scheme is old, it might have a GE model HAA relay installed. This is likely in nuclear power plants of a late 1960s or early 1970s vintage. Continue reading “GE HAA relays in sudden-pressure applications” →

Complying with GDC 17 and 18 – a survey of IEEE Std. 308

Class 1E power systems must be electrically isolated and physically separated

The NRC requires nuclear plants to have both onsite and offsite power systems available to supply safety-related equipment. It also requires that this equipment be periodically inspected and tested so that their condition can be assessed. These requirements are established in General Design Criteria 17 and 18. Continue reading “Complying with GDC 17 and 18 – a survey of IEEE Std. 308” →