Non Class 125V DC Flashcards
What is the capacity of the ‘E’ and ‘F’ batteries?
Each battery has sufficient capacity to independently supply the required loads for 2 hours following the loss of the battery charger connected to the 125 VDC control center at a minimum temperature of 60F in the battery room.
What are the major loads on NKN-D43?
Oscillograph
Turbine Protection
Transformer annunciators
Plant annunciators
What is the normal source of power to the Plant Computer?
NKN-M45 (125V DC control center ‘E’) through a 45kVA inverter to NQ which supplies the plant computer
List the significant loads on NKN-M46
Main Turbine Emergency Oil Pump Emergency Seal Oil Pump Feedwater Pump A Emergency Oil Pump Feedwater Pump B Emergency Oil Pump NAN-S06 Control Power (Norm) NAN-S05 Control Power (Alt) Normal Access Personnel Air Lock Emergency Access Personnel Air Lock NKN-D44 NKN-D45
List the major loads on NKN-M45
Plant Computer (NQ system) NKN-D41 NKN-D42 NKN-D43 NAN-S05 (Norm) NAN-S06 (Alt) Main Generator Primary protection ckts Main Generator Backup protection ckts
A ‘hard ground’ on NKN-M45 (or M46) will give the following indications …
Two yellow lights on the ground detection assembly are LIT, a white light at the NKN-M45 (M46) Control Center is LIT, and the Control Room receives an alarm.
What are the locations of all six 125 VDC distribution panels?
D41 - Turbine Building 100' D42 - Aux Building 100' D43 - Turbine Building 100' D44 - In NKN-M46 D45 - In SSR Room D19 - Chlorinator Building
What are the major loads on NKN-D41?
Switchgear control power
Main Generator auxiliaries
Turbine Building HVAC control
RCP bkr control receives power from …
NKN-D44 (located in NKN-M46)
The ____ Battery connects to NKN-M46 and is nominally rated for _____ Amp-Hours.
‘F’ (NKN-F18)
3460
The SSO cabinet receives power from …
NKN-D45 (in SSR Room)
Control Power to the Cooling Towers has been lost, where and what DC distribution panel would you expect to send an AO to check?
Chlorinator Building, NKN-D19
How does the Turbine Building HVAC system support the NK system?
Two 100% capacity explosion proof exhaust fans provide adequate air flow to the NK system batteries and components for control of temperature and to prevent buildup of potentially explosive H2 concentration levels during normal plant operation. Cooling for the non-class switchgear room and DC equipment on top of battery room is provided by HTN-A02C Air handling unit.
What is the purpose of the mechanical interlock on the ‘EF’ battery charger?
A mechanical interlock is provided between the ‘EF’ output bkrs, which prevents possible closing of both of the bkrs simultaneously and accidentally paralleling both of the 125 VDC control centers NKN-M45 and NKN-M46
How is accumulation of moisture prevented in NKN-M45 and M46?
Thermostatically controlled space heaters (rated at 240V) are provided in the control center, which are located in the bottom of each section and are supplied from 120 VAC sources.
