The flashcards below were created by user
on FreezingBlue Flashcards.
What should a Load Operator always reference prior to switching in a substation?
The Station Operating Order prior to operating any equipment within a substation
Describe the “5 R’s” of switching.
- • Readings
- • Ratings
- • Reclosing
- • Reactors
- • Regulators
- Taking readings, determining the affected equipment ratings, turning off reclosing, calculating how series reactors will share, and dealing with voltage regulators
What is a low-side or low-voltage tie?
Higher-voltage circuits that are normally tied together directly, tied together through lower-voltage ties. Low-voltage (aka low-side) ties can result in transformer and feeder overloads.
What are the two general types of isolation points? Give examples of each type.
Isolating disconnect switches. Other conventional isolation points include circuit switchers, fuses, bus links, and rack-out circuit breakers.
What must be done to an isolation point in order for it to be used in support of a Safety Protection Guarantee?
Enforced with the appropriate Do Not Operate tags (i.e. Clearance, Test & Work, or Guarantee of Isolation tags)
True or False – Voltage Transformer secondaries are Level 5 equipment and therefore, when located inside a Clearance zone, should be opened and tagged Self Protection to prevent backfeed prior to going to work.
True- Although the secondary sides of these transformers are considered Level 5 equipment, the PIC will “reach in” to establish isolation as required.
Why are gas relays opened and tagged Caution when isolating a substation power transformer?
- In order that these relays do not inadvertently operate while working on equipment, they are blocked as
- part of the Safety Protection Guarantee process.
How is a transfer bus used to maintain service to a feeder position that is coming out of service?
When it is necessary to switch substation feeder equipment out of service, the associated feeder’s load can be tied off to the bus-tie or standby position through the transfer bus in the substation. If the capacity of the bus-tie position is great enough, main feeder bus sections can be switched out of service without having to make any field ties.
Describe how series reactors can affect load sharing when paralleling feeders.
When breaking parallel between feeder positions on non-load-break switches in the substation (typically D3 switches), arc reach has to be accounted for. Series reactors significantly affect load sharing if their impedances differ.
Where is the criteria listed for D3 switching involving series reactors?