Circ water

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Circ water
2015-12-03 10:57:10
Circ water advanced systems

Circ water
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  1. Cooling tower blowdown valves (MO-5326A/B)
    • Directs water from the cooling towers to the mixing basin
    • Has overload protection
    • Excessive B/D flow from either CT will alarm "Dilution H2O blo-down flo high" @ 43,000 gpm
  2. CT pump temperature indicators
    • 0-300F
    • -alarm @ 266F stator temperatures
    • 0-200F
    • -alarms @ 167F for bearing temperatures
    • Bring in EK-3501(2) "Clg Twr pump P-39A(B) Hi temp or overload"
  3. Cooling tower pump start permissives
    • Condenser inlet water box full
    • Pump trips clear
    • Emergency stop pushbutton not pushed
    • Lubricating water flow >8gpm (18 gpm alarm)
    • Water box inlet valve closed
    • CT pump discharge valve closed
  4. CT pump trips
    • Differential current
    • Bus undervoltage
    • Ground current
    • Overcurrent
    • -gives "Clg Twr pump P-39A(B) hi temp or overload"
    • Give alarm "Clg Twr pump P-39A(B) trip"
  5. Cooling tower basin level high/low alarm setpoints
    • A basin
    • -high-611.17ft
    • -low-609.8ft
    • B basin
    • -high-610.17ft
    • -low-608.8ft
  6. Dilution water pump starting limitations
    • Pump @ ambient temperature-2 starts
    • Pump running >30 minutes-1 start
    • Pump idle for >60 minutes-1 start
  7. Dilution water pump interlocks
    • Cannot open CV-1054 unless P-40A or P-40B is running
    • CV-1054 closes if no dilution water pumps running
    • Prevents releasing any treated waste to the mixing basin with out dilution water pump running
  8. Operation of cooling tower pump handswitch?
    • Start
    • -condenser inlet (MO-5301/5302) will start to open
    • -@ approximately 33% open on condenser inlet, the cooling tower pump starts
    • -CT pump discharge valve (MO-5305/5306) opens to:
    • --A to 43%
    • --B to 39%

    • Stop
    • -CT pump discharge valve (MO-5305/5306) starts to close
    • -When CT pump discharge valve is approximately 33% open, CT pump trips
    • -CT pump discharge valve full closes
  9. Cooling tower pump starting limitations
    • Pump @ ambient temperature-2 starts
    • Running > 2 hours-1 start
    • Idle for >45 minutes-1 start
    • No more than 3 starts in any 24 hour period
  10. Cooling tower fill valve (MO-5315/MO-5316) indications
    • Light stroke valve
    • Overload
    • -the thermal overloads for these valves are sized to allow for one continuous cycle (from closed to open or open to closed) before opening. These valves take approximately 60 seconds to fully stroke in one direction.  The thermal overload will time out at 116 seconds.
    • -overload trips breaker and gives alarm
  11. Why is operating with > 1 dilution water pump aligned to the mixing basin not allowed?
    Combined flow rate of 80,000gpm to mixing basin has not been analyzed.
  12. CT pump discharge valve (MO-5305/5306) interlocks
    • Valve opens or closes with P-39A/B start/stop and emergency stop pushbutton
    • Valves do not auto close if pump trips due to local trip at the CT pump breaker
    • Has overload protection
    • -trips motor
    • -brings in alarm
  13. What must be done to restart a dilution water pump that has been S/D within 1 hour?
    Any vacuum in the piping must be removed.
  14. How do you switch dilution water pumps discharge from the mixing basin to a cooling tower?
    • Maintain pump discharge pressure with in desired values
    • Throttle open CT fill valve
    • Throttle closed discharge to the mixing basin for the dilution water pump
  15. Changing CT flow from over the top to bypass?
    • Basin level reduction should commence 4 hours prior to bypass valve operation to allow basin level stabilization.
    • If CT deluge system is inoperable and CT is in bypass operation initiate fire tours
  16. Purpose of the white light on the CT pump handswitch?
    • Low pump discharge pipe not full condition and HS for the CT pump in stop position will illuminate the white "Pump start prohibit"
    • -Jumpered out
    • -will still get the light
    • -light will go out when handswitch for pump is in after close position
  17. CT pump emergency stop pushbutton
    • Immediately stops CT pump
    • -CT pump discharge valve (MO-5305/5306) goes full closed
    • - You will recieve EK-3522 (23), ‘Cooling Tower Pump P-39A (B) Trip’
  18. Discharge to the mixing basin valves (MO-5311/5312) indications?
    • Light stroke valves
    • Thermal overload trips breaker and gives alarm
  19. Water box inlet valves(MO-5301/5302) interlocks?
    • Valve opens in response to P-39A(B) start
    • Overload trips breaker and gives alarm
  20. Dilution water pumps
    • 40,000gpm
    • @ less than 38,000gpm vibration can occur
    • -max 14 psig discharge pressure (minimum flow)
    • --normal 11 psig
    • -20 psig max rated

    • Power supplies
    • -P-40A-1C
    • -P-40B-1E
  21. Cooling tower fan trips
    • Turbine trip
    • High vibration (local reset)
    • Deluge actuation (drain piping)(B C/T only)
    • Overload (local reset on breaker)
  22. Cooling tower fire indications/auto actions?
    • Annunciates EK-3330 "Cooling tower E-30B fire" 
    • -15 psig N2 pressure
    • Fire bells and deluge valve trips
    • Cooling tower fan trips (2 fans)
  23. Dilution water pump trips?
    • P-40A
    • -undervoltage
    • -overcurrent (192 amps)
    • -SIAS load shed

    • P-40B
    • -undervoltage
    • -overcurrent (192 amps)
    • -bus 1E trips on SIAS
  24. Actions for water box inlet valve leakage?
    • Operate water box inlet valve to flush debris
    • Attempt to seat valve using the handwheel
    • Drain respective cooling tower
  25. Purpose of the Initiate Reset button on CT fan controls?
    • Resets cooling tower control system
    • -warm reboot (approximately 2 minutes)
    • Clears the alarms
    • Lamp test
    • Used to reestablish communications with the CTs
    • Will lose indication of CT bypass valve and cooling tower level
    • -restores after reboot
  26. Cooling tower bypass valves (MOV-5340/5341/5342/5343)
    • Seal in open/close light stroke valves
    • Have 250 second delay @ 16.7% open
    • -avoids excessive flow to CT basin in too short of a time frame
    • --prevents overflowing basin
  27. P-40A/B discharge to the CTs (MO-5313/5314) indications?
    • Light stroke valves
    • Overload
    • -the thermal overloads for these valves are sized to allow for one continuous cycle (from closed to open or open to closed) before opening. These valves take approximately 60 seconds to fully stroke in one direction.  The thermal overload will time out at 116 seconds.
    • -trips breaker and brings in an alarm
  28. Makeup basin low level alarm?
  29. What will failure to establish an open flow path for the Dilution Water Pump being started cause?
    It may cause the pump(s) to trip due to high motor amps.
  30. Why is operation of more than one Dilution Water Pump aligned to the Mixing Basin is not allowed?
    The combined total flow rate of 80,000 gpm to the Mixing Basin has not been analyzed.
  31. During periods when freezing could occur in the Cooling Towers, the following apply:
    Cooling Tower Bypass Valves should not be closed until Condenser Inlet temperature is ≥80°F

    Cooling Tower Fans should not be started until inlet water temperature is ≥ 80°F with water flow over top of tower

    IF LIA-5320/LIA-5321, Cooling Tower Level Indicators become frozen or inoperable with P-39A/P-39B, Cooling Tower Pumps in service, AND/OR P-40A/P-40B, Dilution Water Pumps filling the Cooling Towers, then station an Operator locally at the affected cooling tower whose primary responsibility is to monitor tower basin level
  32. Minimum temperature for starting cooling tower fans?
    Cooling Tower Fans should not be started below the –30°F outside temperature when Amarillo Gearbox is filled with synthetic oil.

    Starting fans with outside temperatures less than the above temperature requires running warm water over the top of the tower for a period of time to raise the temperature of the gearboxes.