Variable Voltage Substation Electric Fire and Emergency Response

Question from Participant: 

My question is from an emergency response perspective.  It was stated that it took ~ ½ for electricians to de-energize the electrical components before firefighters were allowed in to fight the fire.  This delay causes more damage to equipment and potential propagation of the fire.  Is there not a "master" breaker or switch?


Answer by John Seabury:

You’ve brought up a very good point. It gave me a good opportunity to discuss this with our Facilities Department and get a better understanding of the infrastructure upgrade plans.

The direct answer to your question is "Yes, but…" Yes, there are "master" breakers and switches, but we can’t control them remotely. SLAC’s AC electrical distribution system at present is manual breakers – we have not installed the infrastructure to remotely control them (except see below). We recently underwent an upgrade to our Master Substation that will allow us to remotely control some high voltage breakers in the future, but we aren’t there yet. We do recognize the value in having this capability (and more importantly, our vulnerability in NOT having it), and have begun the preliminary planning to make this happen. One issue were are working on is cyber security for the power distribution networked infrastructure. Before we install the capability to remotely control the main electrical breakers, we are planning the infrastructure with our Information Technologies organization to ensure we have a robust secure network that is protected from unauthorized access.  Once the cyber security issues are addressed and funded, we’re probably 5-10 years out from having remote operation capability due to limited resources to fund and install the infrastructure.

Having said the above, we do have the capability of remotely opening the VVS Secondary Main Breakers – the ones that send power to the modulator distribution breakers - from our control room. Those breakers are integral parts of our safety systems in that interlock violation causes the breakers to open and remove power to the klystrons. But everything else is manual only. That remote operation capability would not have helped us in this case, as the VVS Secondary Main Breaker was the one that fried. We needed to open the breaker upstream of the VVS.

Thanks for your interest. Let me know if I can provide further information.