ML21286A427
Text
BFN-26 TABLE 8.4-1 Sheet 1 AUXILIARY POWER SUPPLIES AND BUS TRANSFER SCHEMES General Remarks
- 1. All breakers which may supply a given bus are interlocked to prevent paralleling supply sources.
- 2. Each bus has provision for manually transferring between normal and alternate sources. Manual transfers of all 4160-V buses are high speed except as otherwise indicated.
- 3. Bus transfers which are initiated automatically by undervoltage are time coordinated to avoid needless transfer of buses toward the load.
- 4. The term "high-speed transfer" applies to 4160-V bus transfers between stored-energy circuit breakers which are controlled for a dead time not exceeding 5 cycles.
- 5. The term "delayed transfer" applies to 4160-V bus transfers supervised by bus residual relays, which permit either the normal supply breaker to trip or the alternate supply breaker to close when the bus voltage decays to a value safe for connected motors. Normally the residual voltage relay will be set at 30 percent voltage. The delayed transfer for 4-V Unit Boards 1A, 1B, 2A, and 2B has been disabled.
- 6. Automatic bus transfer is blocked by operation of bus overcurrent or current differential relays for all 4160-V buses. Except for those minor 480-V buses normally supplied from main 480-V buses of the normal auxiliary power system, all 480-V automatic bus transfers are blocked by bus overcurrent protective devices.
- 7. The offsite power circuits through the CSSTs do not have the capacity to support all connected loads for electric plant alignments where there is an existing pre-load on the CSST supplied 4160-V start buses or if a CSST is out of service. This is addressed by manually disabling the automatic transfer of selected 4160-V unit boards and/or 4-kV common boards. See FSAR figures for any limitations on usage of power sources.
BFN-26 TABLE 8.4-1 Sheet 2 AUXILIARY POWER SUPPLIES AND BUS TRANSFER SCHEMES Power Sources Item Board and/or Main Bus Normal Alternate Remarks 1 4160-V Start bd 1 - Start COM SS TR A, COM SS TR B, Automatic high speed transfer from the normal to Bus 1A X-winding fed from X-winding fed from the alternate source is initiated by operation of Athens or Trinity Athens or Trinity of protective relays for the normal source common 161 kV lines 161 kV lines station service transformer, or for the 161-kV line feeding that transformer. The bus will be automatically returned to its normal source 40 cycles after return of voltage on the normal source. This time delay is to avoid needless switching during 161-kV line reclosing operations. If alternate source voltage is abnormally low, the normal source breaker will not trip (no transfer); if the normal source breaker trips again within 15 seconds, it will lock out with an alarm, and operator reset will be required.
2 4160-V Start bd 1 - Start COM SS TR B, COM SS TR A, (See Remarks under Item 1)
Bus 1B X-winding, fed from X-winding fed from Athens or Trinity Athens or Trinity 161 kV lines 161 kW lines 3 4160-V Start bd 2 - Start COM SS TR A, COM SS TR B, Automatic high speed transfer from the normal to Bus 2A Y-winding fed from Y-winding fed from the alternate source is initiated by operation of Athens or Trinity Athens or Trinity protective relays for the normal source common 161 kV lines 161 kV lines station service transformer, or for the 161-kV line feeding that transformer. Automatic delayed transfer from the normal to the alternate source is initiated by time delay undervoltage relays. The bus will be automatically returned to its normal source 40 cycles after return of voltage on the normal source. This time delay is to avoid needless switching during 161-kV line reclosing operations. If alternate source voltage is abnormally low, the normal source breaker will not trip (no transfer); if the normal source breaker trips again within 15 seconds, it will lock out with an alarm, and operator reset will be required.
BFN-26 TABLE 8.4-1 Sheet 3 AUXILIARY POWER SUPPLIES AND BUS TRANSFER SCHEMES Power Sources Item Board and/or Main Bus Normal Alternate Remarks 4 4160-V Start bd 2 - Start COM SS TR B, COM SS TR A, (See Remarks under Item 3)
Bus 2B Y-winding fed from Y-winding fed from Athens or Trinity Athens or Trinity 161 kV lines 161 kV lines 4a 4160-V Bus Tie Board Alternate 1 5 Shutdown Bus 1 (4160-V) 4 kV unit bd 1A or 4 kV unit bd 2B or The two independent shutdown buses normally 2B of preselected 1A (that source not supply 4160-V power to assigned 4160-V shutdown on-line unit preselected for boards, with each bus serving as the normal "normal") source to two boards and as the alternate source to the two other boards. Of the two possible Alternate 2 feeders to each shutdown bus from the two 4 kV unit boards, one feeder is preselected manually Same 4 kV unit bd as the normal source to that bus. Automatic of preselected delayed transfer from the normal to an alternate unit, but with a 1 source is initiated by undervoltage on the delayed manual normal source. Automatic high-speed transfer from transfer to start the normal to an alternate 1 source is initiated bus 1A or 1B when the normal source 4 kv unit board normal source breaker trips. If an alternate 1 source is not available, the transfer is prevented, and there is a delayed Alternate 3 manual transfer to the alternate 2 source. Automatic transfer is blocked after time delay in the presence of an accident signal. Alternate 3 source may be Two diesel generators selected manually only.
if required for back-feeding a preselected 4 kv unit bd (1A, 2B)
See also remarks for items 13, 14, 15, and 16.
BFN-26 TABLE 8.4-1 Sheet 4 AUXILIARY POWER SUPPLIES AND BUS TRANSFER SCHEMES Power Sources Item Board and/or Main Bus Normal Alternate Remarks Alternate 1 6 Shutdown Bus 2 (4160-V) 4 kV unit bd 1B or 4 kV unit bd 2A (See Remarks under Item 5) 2A, of preselected or 1B (that source on-line unit not preselected for "normal")
Alternate 2 Same 4 kV unit bd of preselected unit, but with a delayed manual transfer to start bus 1A or 1B Alternate 3 Two diesel generators, if required for back-feeding a preselected 4 kV unit bd (1B, 2A) See also remarks for items 13, 14, 15, and 16 7 4 kV Recirculation Pump Boards:
(a) Unit 1, Pump VFD 1A Unit SS TR 1A Start Bus 2A Automatic high-speed transfer from the normal to Board 1 Y-winding the alternate source is initiated by main generator unit trip relays. Automatic delayed transfer from the normal to the alternate source is initiated by high-speed voltage relay.
BFN-26 TABLE 8.4-1 Sheet 5 AUXILIARY POWER SUPPLIES AND BUS TRANSFER SCHEMES Power Sources Item Board and/or Main Bus Normal Alternate Remarks (b) Unit 1, Pump VFD 1B Unit SS TR 1A Start Bus 2B Board 1 Y-winding (c) Unit 2, Pump VFD 2A Unit SS TR 2A Start Bus 2A Board 2 Y-winding (d) Unit 2, Pump VFD 2B Unit SS TR 2A Start Bus 2B Board 2 Y-winding (e) Unit 3, Pump VFD 3A Unit SS TR 3A Start Bus 2A Board 3 Y-winding (f) Unit 3, Pump VFD 3B Unit SS TR 3A Start Bus 2B Board 3 Y-winding 8 4 kV Unit Boards, Unit 1 Alternate 1 (a) 4 kV unit bd 1A Unit SS TR 1B Start bus 1A Automatic high-speed transfer from the normal to X-winding alternate 1 source is initiated by generator or switchyard breaker failure relaying, USST protective relaying, main transformer protective relaying, or generator backup protection relaying (See General Remarks Numbers 5 and 7)
Alternate 2 Backfeed from shut- Manual only through backfeed switches down bus
BFN-26 TABLE 8.4-1 Sheet 6 AUXILIARY POWER SUPPLIES AND BUS TRANSFER SCHEMES Power Sources Item Board and/or Main Bus Normal Alternate Remarks Alternate 1 (See Remarks Item 8(a))
(b) 4 kV unit bd 1B Unit SS TR 1B Start bus 1B Y-winding Alternate 2 Backfeed from shut- Provisions are included for backfeeding diesel-down bus generator power from the 4-kV shutdown boards into the 4160-V unit boards for reactor plant shutdown cooling if all plant power, other than diesel generator power, is lost. The plant design includes a mode of operation for running one condenser circulating water pump to permit use of the condensers as a heat sink.
Alternate 1 (c) 4 kV unit bd 1C Unit SS TR 1A Start bus 1B Automatic high-speed transfer from the normal to the X-winding alternate 1 source is initiated by generator or switchyard breaker failure relaying. USST protective relaying, main transformer protective relaying or generator backup protection relaying. Automatic delayed transfer from the normal to the alternate 1 source is initiated by a time delay voltage relay.
(See General Remarks Number 7).
9 4 kV Unit Boards, Unit 2 Alternate 1 (a) 4 kV unit bd 2A Unit SS TR 2B Start Bus 1A (See Remarks Item 8(a))
X-winding Alternate 2 Backfeed from shut-down bus
BFN-26 TABLE 8.4-1 Sheet 7 AUXILIARY POWER SUPPLIES AND BUS TRANSFER SCHEMES Power Sources Item Board and/or Main Bus Normal Alternate Remarks Alternate 1 (b) 4 kV unit bd 2B Unit SS TR 2B Start Bus 1B (See Remarks Item 8(a))
Y-winding Alternate 2 Backfeed from shut-down bus Alternate 1 (c) 4 kV unit bd 2C Unit SS TR 2A Start bus 1A (See Remarks Item 8(c))
X-winding (See General Remarks Number 7) 10 4 kV Unit Boards, Unit 3 Alternate 1 (a) 4 kV unit bd 3A Unit SS TR 3B Start bus 1A Automatic high-speed transfer from the normal to X-winding the alternate 1 source is initiated by generator or switchyard breaker failure relaying, USST protective relaying, main transformer protective relaying, or generator backup protection relaying. Automatic delayed transfer from the normal to the alternate 1 source is initiated by a time delay voltage relay.
(See General Remarks Number 7)
BFN-26 TABLE 8.4-1 Sheet 8 AUXILIARY POWER SUPPLIES AND BUS TRANSFER SCHEMES Power Sources Item Board and/or Main Bus Normal Alternate Remarks Alternate 2 Backfeed from shut- Manual only through backfeed switches.
down boards Alternate 1 (b) 4 kV unit bd 3B Unit SS TR 3B Start bus 1B (See Remarks Item 10(a))
Y-winding Alternate 2 Backfeed from shut- Provisions are included for backfeeding diesel down boards generator power from the 4-kV shutdown boards into the 4160-V unit boards for reactor plant shutdown cooling if all plant power, other than diesel generator power, is lost. The plant design includes a mode of operation for running one condenser circulating water pump to permit use of the condensers as a heat sink.
Alternate 1 (c) 4 kV unit bd 3C Unit SS TR 3A Start bus 1A (See Remarks Item 10(a))
X-winding 11 4 kV Common Board A Unit SS TR 1A Start Bus 1A Automatic delayed transfer from the X-winding normal to the alternate source is initiated by undervoltage on the normal source, subject to voltage check on the alternate source. Automatic delayed transfer back to the normal source is initiated by return of normal voltage on the normal source. Manual transfers in either direction are the fast transfer type.
(See General Remarks Number 7) 12 4 kV Common Board B Unit SS TR 2A Start Bus 1B (See General Remarks Number 7)
X-winding Alternate 2 13 4 kV Shutdown Board A Shutdown Bus 1 Shutdown Bus 2 (See also remarks for items 5 and 6.)
BFN-29 TABLE 8.4-1 Sheet 9 AUXILIARY POWER SUPPLIES AND BUS TRANSFER SCHEMES Power Sources Item Board and/or Main Bus Normal Alternate Remarks Manual delayed transfer from Diesel Generator to Shutdown Bus when electrical loads permit operators manually transfer the boards to the alternate 4.16-kV Shutdown bus. Alternate 2 source is tripped in the presence of a common accidental signal.
Alternate 1 All diesel generators are automatically started Diesel generator A by an accident signal, or by loss of voltage on its shutdown board for 1.5 seconds, or degraded Alternate 3 voltage for 4 seconds, or a voltage unbalance. After 5 seconds without voltage on the shutdown board, all its supply breakers and all its loads except 4160-480-V Manual, access con- transformers are all automatically tripped.
nection to diesel Alternate 1 source is then automatically generator 3A via 4-kv connected. Manual return to the normal auxiliary power shutdown board 3EA system is permitted if normal auxiliary power system voltage returns.
Provision is made to manually select alternate 3 source.
Alternate 2 14 4 kV Shutdown Board B Shutdown Bus 1 Shutdown Bus 2 Alternate 1 Diesel generator B Alternate 3 Manual, access con-nection to diesel generator 3B via 4-kV shutdown board 3EB
BFN-26 TABLE 8.4-1 Sheet 10 AUXILIARY POWER SUPPLIES AND BUS TRANSFER SCHEMES Power Sources Item Board and/or Main Bus Normal Alternate Remarks Alternate 2 15 4 kV Shutdown Board C Shutdown Bus 2 Shutdown Bus 1 Alternate 1 Diesel generator C Alternate 3 Manual, access to diesel generator 3C via 4-kv shutdown board 3EC Alternate 2 16 4 kv Shutdown Board D Shutdown Bus 2 Shutdown Bus 1 Alternate 1 Diesel generator D Alternate 3 Manual, access to diesel generator 3D via 4-kV shutdown board 3ED 16a 4 kV Shutdown Board 3EA 4 kV Unit Board 3A Alternate 1 Provisions are included for backfeeding diesel generator power from the shutdown boards into the Diesel generator 3A 4160-V unit boards for reactor plant shutdown cooling if all plant power, other than diesel generator power, is lost. For this purpose, means are provided to manually synchronize 4-kV shutdown boards.
BFN-26 TABLE 8.4-1 Sheet 11 AUXILIARY POWER SUPPLIES AND BUS TRANSFER SCHEMES Power Sources Item Board and/or Main Bus Normal Alternate Remarks Alternate 1 16b 4 kV Shutdown Board 3EB 4 kV Unit Board 3A Diesel generator 3B Alternate 1 16c 4 kV Shutdown Board 3EC 4 kV Unit Board 3B Diesel generator 3C Alternate 1 16d 4 kV Shutdown Board 3ED 4 kV Unit Board 3B Diesel generator 3D
BFN-26 TABLE 8.4-1 Sheet 12 AUXILIARY POWER SUPPLIES AND BUS TRANSFER SCHEMES Power Sources Item Board and/or Main Bus Normal Alternate Remarks 17 480-V Water Supply Board Alternate 1 (a) Bus 1 4 kV unit bd 1B Bus 2 (Item 17b) Automatic transfer from the normal to the via TR TW1 alternate source is initiated by time-Alternate 2 undervoltage on the normal source. Return to the normal source is automatic upon return of voltage Bus 3 (Item 17c) to the normal source.
Alternate 1 (b) Bus 2 4 kV unit bd 2B Bus 1 (Item 17a) via TR TW2 Alternate 2 Bus 3 (Item 17c)
Alternate 1 (c) Bus 3 4 kV unit bd 3B Bus 2 (Item 17b) via TR TW3 Alternate 2 Bus 1 (Item 17a) 18 480-V Unit Boards (a) Unit 1, 480-V Unit Bd 1A 4 kV unit bd 1A 4 kV com bd B Automatic transfer from the normal to the via TR TU1A (via TR TEB) alternate source is initiated by time-undervoltage on the normal source. Return to the normal source is automatic upon return of voltage to the normal source.
(b) Unit 1, 480-V Unit Bd 1B 4 kV unit bd 1B 4 kV com bd B via TR TU1B (via TR TEB)
BFN-26 TABLE 8.4-1 Sheet 13 AUXILIARY POWER SUPPLIES AND BUS TRANSFER SCHEMES Power Sources Item Board and/or Main Bus Normal Alternate Remarks (b) Unit 1, 480-V Unit Bd 1B 4 kV unit bd 1B 4 kV com bd B via TR TU1B (via TR TEB)
(c) Unit 2, 480-V Unit Bd 2A 4 kV unit bd 2A 4 kV com bd B via TR TU2A (via TR TEB)
(d) Unit 2, 480-V Unit Bd 2B 4 kV unit bd 2B 4 kV com bd A via TR TU2B (via TR TEA)
(e) Unit 3, 480-V Unit Bd 3A 4 kV unit bd 3A 4 kV com bd A via TR TU3A (via TR TEA)
(f) Unit 3, 480-V Unit Bd 3B 4 kV unit bd 3B 4 kV com bd A via TR TU3B (via TR TEA) 19 480-V Lighting Boards (a) 480-V Lighting Bd 1 4 kV com bd A 4 kV com bd B Transfer between sources is manual only. Each via TR TL1 (via TR TEB) 480-V lighting board serves as the power source, via single phase voltage regulators (Unit 2 only) and 480-V to 240/120-V stepdown transformers, for three 240/120-V lighting boards per unit. These unit lighting boards serve various distribution cabinets in the plant.
(b) 480-V Lighting Bd 2 4 kV com bd A 4 kV com bd B via TR TL2 (via TR TEB)
(c) 480-V Lighting Bd 3 4 kV com bd B 4 kV com bd A via TR TL3 (via TR TEA) 20 480-V Common Boards
BFN-26 TABLE 8.4-1 Sheet 14 AUXILIARY POWER SUPPLIES AND BUS TRANSFER SCHEMES Power Sources Item Board and/or Main Bus Normal Alternate Remarks (a) 480-V Common Bd 1 Bus A 4 kV com bd A Bus B of Item 20a Automatic transfer from the normal to the via TR TC1A alternate source is initiated by time-undervoltage on the normal via TR TC1B source.
Bus B 4 kV com bd B Bus A of Item 20A Return to the normal source is automatic upon via TR TC1B return of voltage to the normal source.
(b) 480-V Common Bd 2 Bus A 4 kV com bd A Bus B of Item 20b via TR TC2A Bus B 4kV com bd B Bus A of Item 20b via TR TC2B (c) 480-V Common Bd 3 Bus A 4 kV com bd A Bus B of Item 20c via TR TC3A Bus B 4 kV com bd B Bus A of Item 20c via TR TC3B 21 480-V Service Building Main Board Bus A 4 kV com bd A Bus B of Item 21 Same as remarks for Item 20.
via TR TSBA Bus B 4 kV com bd B Bus A of Item 21 via TR TSBB 22 480-V Radwaste Boards Board 1 480-V Serv Bldg Bd 1) 480-V com bd 1 If the normal feed should fail, a manually (item 21) Bus A 2) 480-V Diesel Aux actuated transfer to the alternate source Bd-A may be made.
Board 2 480-V com bd 1 1) 480-V Serv Bldg Bd Item 20 Bus B (item 21)
- 2) 480-V Diesel Aux Bd-B Board 3 480-V Service 480-V Common board 1 Building board Bus A (Item 21) Bus B
BFN-26 TABLE 8.4-1 Sheet 15 AUXILIARY POWER SUPPLIES AND BUS TRANSFER SCHEMES Power Sources Item Board and/or Main Bus Normal Alternate Remarks 23 480-V Auxiliary Boiler Bd Bus A 480-V com bd 3, 480-V com bd 1, Both buses are normally fed from source shown, Bus A Bus B and with the manually operated bus tie breaker Bus B closed. Automatic transfer of both buses from 480-V com bd 3, 480-V com bd 1, the normal to the alternate source is initiated Bus Bus B by time-undervoltage on the normal source. Return to the normal source is automatic upon return of voltage to the normal source.
24 480-V Control Bay Vent Boards Board A 480-V Shutdown Bd 1A 480-V com Bd 1 The automatic transfer from the safety related normal source to the non-safety related alter-Board B 480-V HVAC Bd B 480-V com Bd 3 nate source has been disabled by opening the emergency feeder breaker for Control Bay Vent Board A and placing the transfer switch "43" in manual mode for Control Bay Vent Board B. Manual transfer to the alternate source will be administratively controlled.
25 480-V Turbine MOV Boards (a) Unit 1, Board 1A 480-V unit bd 1A 480-V com bd 1, Automatic transfer from the normal to the Bus A alternate source is initiated by time-initiated by time-undervoltage on the normal (b) Unit 1, Board 1B 480-V unit bd 1B 480-V com bd 2-Bus B source. Return to the normal source is automatic upon return of voltage to the normal source.
(c) Unit 1, Board 1C 480-V unit bd 1B 480-V com bd 2-Bus B (d) Unit 2, Board 2A 480-V unit bd 2A 480-V com bd 3-Bus B (e) Unit 2, Board 2B 480-V unit bd 2B 480-V com bd 2-Bus B (f) Unit 2, Board 2C 480-V unit bd 2B 480-V com bd 2-Bus A (g) Unit 3, Board 3A 480-V unit bd 3A 480-V com bd 3-Bus A (h) Unit 3, Board 3B 480-V unit bd 3B 480-V com bd 3-Bus B (i) Unit 3, Board 3C 480-V unit bd 3B 480-V com bd 2-Bus A
BFN-26 TABLE 8.4-1 Sheet 16 AUXILIARY POWER SUPPLIES AND BUS TRANSFER SCHEMES Power Sources Item Board and/or Main Bus Normal Alternate Remarks 26 480-V Condensate Demin-eralizer Boards (a) Unit 1 480-V unit bd 1A 480-V shdn bd 1B In case of failure of the normal source, automatic transfer is made to an energized alternate source. Upon restoration of the normal source, automatic return to normal is effected.
(b) Unit 2 480-V unit bd 2A 480-V shdn bd 2B (c) Unit 3 480-V unit bd 3A 480-V shdn bd 3B 27 480-V Reactor Building Vent Boards (a) Unit 1, Board 1A 480-V unit bd 1A 480-V com bd 1-Bus B See remarks of Item 23.
(b) Unit 1, Board 1B 480-V unit bd 1A 480-V com bd 1-Bus B (c) Unit 2, Board 2A 480-V unit bd 2A 480-V com bd 3-Bus A (d) Unit 2, Board 2B 480-V unit bd 2A 480-V com bd 3-Bus A (e) Unit 3, Board 3A 480-V unit bd 3A 480-V com bd 3-Bus B (f) Unit 3, Board 3B 480-V unit bd 3A 480-V com bd 3-Bus B 28 480-V Turbine Building Vent Boards (a) Unit 1, Board 1A 480-V unit bd 1A 480-V com bd 1-Bus A See remarks on Item 23.
(b) Unit 1, Board 1B 480-V unit bd 1B 480-V com bd 2-Bus B (c) Unit 2, Board 2A 480-V unit bd 2A 480-V com bd 3-Bus B (d) Unit 2, Board 2B 480-V unit bd 2B 480-V com bd 2-Bus A (e) Unit 3, Board 3A 480-V unit bd 3A 480-V com bd 3-Bus A (f) Unit 3, Board 3B 480-V unit bd 3B 480-V com bd 2-Bus A
BFN-26 TABLE 8.4-1 Sheet 17 AUXILIARY POWER SUPPLIES AND BUS TRANSFER SCHEMES Power Sources Item Board and/or Main Bus Normal Alternate Remarks 29 480-V Shutdown Boards (a) Unit 1, 480-V Shutdown Bd 1A 4 kV shutdown bd A 4 kV shutdown bd B Transfer from the normal to the alternate via TR TS1A via TR TS1E source is manual. Interlocking is provided to prevent manually transferring to a faulted board and to prevent paralleling two sources.
(b) Unit 1, 480-V Shutdown Bd 1B 4 kV shutdown bd C 4 kV shutdown bd B Remark (a) via TR TS1B via TR TS1E (c)
(c) Unit 2, 480-V shutdown Bd 2A 4 kV shutdown bd B 4 kV shutdown bd C via TS2A via TR TS2E (d) Unit 2, 480-V shutdown Bd 2B 4 kV shutdown bd D 4 kV shutdown bd C Remark (a) via TR TS2B via TR TS2E (e) Unit 3, 480-V Shutdown Bd 3A 4kV shutdown bd 3EA 4 kV shutdown bd 3EB Remark (a) via TR TS3A via TR TS3E (f) Unit 3, 480-V Shutdown Bd 3B 4 kV shutdown bd 3EC 4 kV shutdown bd 3EB Remark (a) via TR TS3B via TR TS3E 30 480-V Reactor MOV Boards Remark 29(a)
(a) Unit 1, 480-V Reac MOV Bd 1A 480-V Shutdown Bd 1A 480-V Shutdown Bd 1B Remark 29(a)
(b) Unit 1, 480-V Reac MOV bd 1B 480-V Shutdown Bd 1B 480-V Shutdown Bd 1A Remark 29(a)
(c) Unit 1, 480-V Reac MOV Bd 1C 480-V Shutdown Bd 1B 480-V Shutdown Bd 1A Remark 29(a)
BFN-26 TABLE 8.4-1 Sheet 18 AUXILIARY POWER SUPPLIES AND BUS TRANSFER SCHEMES Power Sources Item Board and/or Main Bus Normal Alternate Remarks (f) Unit 2, 480-V Reac MOV Bd 2A 480-V Shutdown Bd 2A 480-V Shutdown Bd 2B Transfer from the normal to the alternate source alternate source is manual. Interlocks prevent transferring a fault from one source to another and paralleling sources.
(g) Unit 2, 480-V Reac MOV Bd 2B 480-V Shutdown Bd 2B 480-V Shutdown Bd 2A Transfer from the normal to the alternate source is manual. Interlocks prevent transferring a fault from one source to another and paralleling sources.
(h) Unit 2, 480-V Reac MOV Bd 2C 480-V Shutdown Bd 2B 480-V Shutdown Bd 2A Transfer from the normal to the alternate source manual. Interlocks prevent transferring a fault from one source to another and paralleling sources.
(i) Unit 2, 480-V Reac MOV Bd 2D 480-V Shutdown Bd 2A 480-V Shutdown Bd 2B Transfer from the normal to the alternate source is initiated by manual actions at the 480V Shutdown Boards. These manual actions open the normal feeder breaker and close the alternate feeder breaker, which is sensed by time-undervoltage on the normal source. Interlocks prevent transferring a fault from one source to another and paralleling sources. Return to the normal source is manual upon return of voltage to the normal source.
(j) Unit 2, 480-V Reac MOV Bd 2E 480-V Shutdown Bd 2B 480-V Shutdown Bd 2A Transfer from the normal to the alternate source is initiated by manual actions at the 480V Shutdown Boards. These manual actions open the normal feeder breaker and close the alternate feeder breaker, which is sensed by time-undervoltage on the normal source. Interlocks prevent transferring a fault from one source to another and paralleling sources. Return to the normal source is manual upon return of voltage to the normal source.
(k) Unit 3, 480-V Reac MOV Bd 3A 480-V Shutdown Bd 3A 480-V Shutdown Bd 3B Transfer from the normal to the alternate source is manual. Interlocks prevent transferring a fault from one source to another and paralleling sources.
BFN-26 TABLE 8.4-1 Sheet 19 AUXILIARY POWER SUPPLIES AND BUS TRANSFER SCHEMES Power Sources Item Board and/or Main Bus Normal Alternate Remarks (l) Unit 3, 480-V Reac MOV Bd 3B 480-V Shutdown Bd 3B 480-V Shutdown Bd 3A Transfer from the normal to the alternate source is manual.
Interlocks prevent transferring a fault from one source to another and paralleling sources.
(m) Unit 3, 480-V Reac MOV Bd 3C 480-V Shutdown Bd 3B 480-V Shutdown Bd 3A Transfer from the normal to the alternate source is manual.
Interlocks prevent transferring a fault from source to another and paralleling sources.
(n) Unit 3, 480-V Reac MOV Bd 3D 480-V Shutdown Bd 3A 480-V Shutdown Bd 3B Automatic transfer from the normal to the alternate source is initiated by manual actions at the 480V Shutdown Boards. These manual actions open the normal feeder breaker and close the alternate feeder breaker, which is sensed by time-undervoltage on the normal source. Interlocks prevent transferring a fault from one source to another and paralleling sources. Return to the normal source is manual upon return of voltage to the normal source.
(o) Unit 3, 480-V Reac MOV Bd 3E 480-V Shutdown Bd 3B 480-V Shutdown Bd 3A Automatic transfer from the normal to the alternate source is initiated by manual actions at the 480V Shutdown Boards. These manual actions open the normal feeder breaker and close the alternate feeder breaker, which is sensed by time-undervoltage on the normal source. Interlocks prevent transferring a fault from one source to another and paralleling sources. Return to the normal source is manual upon return of voltage to the normal source.
31 480-V Diesel Auxiliary Boards (a) 480-V Diesel Aux Bd A 4 kV Shutdown Bd A 4 kV Shutdown Bd B Transfer from the normal to the alternate source via TR TDA via TR TDE is manual. Interlocks prevent transferring a fault from one source to another and paralleling sources.
(b) 480-V Diesel Aux Bd B 4 kV Shutdown Bd D 4 kV Shutdown Bd B Remark (a) via TR TDB via TR TDE (c) 480-V Diesel Aux Bd 3EA 480-V Shutdown Bd 3A 480-V Shutdown Bd 3B Remark (a)
(d) 480-V Diesel Aux Bd 3EB 480-V Shutdown Bd 3B 480-V Shutdown Bd 3A Remark (a) 32 480-V HVAC Boards (b) 480V HVAC Board B 4-kV Shutdown Bd 3ED 480-V Shutdown Bd 3B Transfer from the normal to the alternate source is manual.
Interlocking is provided to prevent manually transferring to a faulted board and to prevent paralleling two sources.
BFN-26 Table 8.4-2 (Deleted by Amendment 11)
BFN-26 Table 8.4-3 (Deleted by Amendment 11)
BFN-26 Table 8.4-4 (Deleted by Amendment 10)
BFN-26 Table 8.4-5 (Deleted by Amendment 10)
BFN-26 Table 8.4-6 (Deleted by Amendment 10)
BFN-26 Table 8.4-7 (Deleted by Amendment 13)
BFN-26 Table 8.4-8 (Deleted by Amendment 10)
BFN-26 Table 8.4-9 (Deleted by Amendment 10)
BFN-26 Table 8.4-10 (Deleted by Amendment 10)
BFN-26 Table 8.4-11 (Deleted by Amendment 11)
BFN-26 Table 8.4-12 (Deleted by Amendment 10)
BFN-26 Table 8.4-13 (Deleted by Amendment 10)
BFN-26 Table 8.4-14 (Deleted by Amendment 13)