SSPS Flashcards
What does Redundancy do for us and what are examples?
Single failures neither cause nor prevent Rx Trip/ESF Actuation
Redundant sensors and independent channels with a coincident trip
What does Independence do for us and what are examples?
Train separation.
Separate sensors with separate: power supplies, racks, panel mounted equipment and relays for actuation of protective functions.
What does Diversification do for us?
Several methods to perform similar functions
What does it mean to be Fail Safe?
Loss of power results Reactor Trip/ESF Actuation
Does CTS actuate on a loss of power?
NO
Energize to actuate
What does Control/Protection Separation mean?
Electrical isolation / physical separation maintains control systems separate and distinct from protective system
What does Testability mean?
Permits testing during normal ops w/o initiating protective action
What does coincidence mean?
Meets single failure criteria such that reliability is ensured and allows in-service testing. Requires minimum logic to produce output functions.
What will happen if you lose both 15 VDC OR both 48 VDC Power?
Rx Trip
What powers Train A Slave Relays?
CRID I
What powers Train B Slave Relays?
CRID IV
What does a loss of CRID I or CRID IV do?
prevents actuation of ESF equipment on associated train
Where does the General Warning come from?
Logic Cabinets
What will give you a general warning?
Bypass Breaker Closed
Loss of 48V DC or 15V DC power supply
Output mode selector switch in TEST
What does a general warning on both trains do?
Trips Rx
What is the purpose of Test Injection Switches?
Disconnects Xmitter, connects to test input jacks for the Xmitter
What is the purpose of Bistable Test Switches?
Switch to TEST when instrument fails.
Gives SSPS the trip signal
For CTS, Bistables are bypassed
What is the purpose of RPS BYPASS SWITCHES?
Puts power to logic cabinet regardless of input, allowing you to test the input drawer (using bistable test switch) without chance of causing an actuation.
You never get a trip signal.
What is the purpose of OUTPUT MODE SELECTOR SWITCH?
TEST- disables all slave relays for an entire train by replacing 120 VAC Slave Relay power with 15 VDC
(operated for SSPS testing)
What is the purpose of INPUT ERROR INHIBIT SWITCHES?
Removes grounds from all input relay contacts.
Keeps universal logic cards from sensing a change in input.
What happens with the MULTIPLEXOR TEST SWITCH in Normal?
Sends signals to PPC and Control Boards
What happens with the MULTIPLEXOR TEST SWITCH in Inhibit?
Inhibits data output from train in test
What happens with the MULTIPLEXOR TEST SWITCH in A+B?
Alternately inhibits data of one train
What does the MULTIPLEXOR “do”?
NOTHING
Goes to Status Lights, Alarms and PPC
What do the Isolation Amplifiers do?
Ensures failure in ctrl system does not propagate to protection system and physical separation by placing in separate ctrl group racks
What does the Rx Trip Breaker Trip Coil do?
Trips breakers when ENERGIZED
What does the Rx Trip Breaker UV Coil do?
From UV Coil driver in Logic Cab
Trips when 48vDC from SSPS is lost
Does the Rx Trip Breaker UV Coil need control power?
NO
What does the Rx Trip Breaker Shunt Coil do?
Same actuation method as UV
Gives power to trip bkr to make it trip
Does the Rx Trip Breaker Shunt Coil need control power?
YES
Do Rx Trip Bypass Breakers have SHUNT Coils?
NO
What happens if both Rx Trip Bypass breakers are in closed?
Trips Bypass Breakers
What are Input Bay Direct Feeds powered from?
SSPS Input Bays
What are indirect feeds from the Input Bay powered from?
Protection Racks
What are the inputs to OTΔT?
ΔT
Tave
AFD
Pzr Press
What does OTΔT protect from?
DNB
What rare the inputs for OPΔT?
ΔT
Tave
What does OPΔT protect from?
KW/ft
