TE K-004 - BLDG 25910 CHW and HTW Operations (Final).docx

Technical Exhibit K-004 - BLDG 25910 Chilled Water and High Temp Water Operations 25910 Chiller Start/Stop Sequence of Operation

Each chiller can be remotely started or stopped through the UMCS InfoScan 2000 Terminal. All Operations are automatic except for Chiller selection and the selection of how many chiller s should operate.

Starting a chiller When the Operator determines a chiller needs to be started, the operator will initiate the Chiller Start sequence for the desired chiller by changing the Chiller Request state from Off to On. The sequence proceeds as follows:

1. Detect Chiller Request is On and Chiller is not already On.

2. Check for chiller availability. If Chiller Control is not marked Out of Service and is not in the Alarm state and the Chiller HOR (Hand, Off, Remote switch) is not in Hand position, and the Chiller Trip alarm is not active, the start sequence shall proceed. Otherwise the start sequence shall abort with the Chiller Request changed to Off and the Chiller Request point marked Out of service.

3. If there are more chilled water pumps running than chillers, proceed to Step 5.

4. Send a start request to the chilled water pump manager.

5. If there are more condenser pumps running than proceed to Step 7.

6. Send a start request to the condenser pump manager.

7. Wait for a maximum of 5 minutes for the chilled water and condenser pumps to start. When the pumps are successfully started, the pump manager start requests will switch to OFF. If either pump fails to start, perform the failed chiller shutdown sequence.

8. Open Condenser and Chilled water isolation valves to 100% open.

9. Command chiller to start. If chiller fails to start within 5 minutes (programmable), perform the failed chiller shutdown sequence.

Once the chiller is running, the operator should adjust chilled water leaving setpoint and demand limit setpoint.

Stopping a chiller When the operator determines a chiller needs to be stopped, the operator will first unload the chiller and then initiate the stop sequence for the desired chiller by changing the Chiller 'Request' state from On to Off The sequence proceeds as follows:

1. Detect that Chiller Request is Off and Chiller Control is On

2. Set Chiller Control to Off

3. Wait up to 5 minutes (programmable) for the Chiller Feedback to indicate that the chiller is Off. Log an alarm if the chiller does not go off.

4. If, after the wait time has elapsed, the Chiller Feedback does not indicate that the chiller is Off, log an alarm for the chiller, and mark the Chiller Control out of service. Abort the Stop Chiller sequence without closing isolation valves or stopping any pumps (assume the chiller is actually running). Operator intervention is required.

5. Close the Condenser and Chilled water isolation valves to 0% open.

6. If there are more condenser pumps running than chillers left running, send a stop request to the condenser pump manager.

7. If there are more chilled water pumps running than chillers left running, send a stop request to the chilled water pump manager.

Failed Chiller Shutdown Sequence This sequence is used to abort a chiller Startup sequence or to handle a chiller going off when it is Commanded on. The sequence proceeds as follows:

1. Set Chiller Control to Off.

2. Set Chiller Request to Off.

3. Set Chiller Request to Out of Service.

4. Close the Condenser and Chilled water isolation valves.

5. If there are more condenser pumps running than chillers left running, send a stop request to the condenser pump manager.

6. If there are more chilled water pumps running than chillers left running, send a stop request to the chilled water pump manager.

Chiller Start/Stop Controls

Fort Gordon 25910 CEP 1/2

Chiller Start/Stop Controls

Fort Gordon 25910 CEP 2/2

25910 Chilled Water Pumps Start / Stop Sequence

The Chilled Water pumps may be used interchangeably. When starting a pump, the available pump with the least runtime is preferred. When stopping a pump, the running pump with the most runtime is preferred. A pump is available to if it is currently Commanded Off and shows a feedback of Off, it is not marked out of service, its HOR (Hand, Off, Remote switch) is not in Hand, and its Emergency Stop is not active. The pump management software interacts with the Chiller Start / Stop sequence and other control sources through the use of two software points; Pump Start Request and Pump Stop Request.

To start the next available pump, the Pump Start Request is turned On. Once the pump management software has activated a pump, it turns the Pump Start Request Off.

To stop a pump, the Pump Stop Request is turned On. Once the pump management software has stopped a pump, the Pump Stop Request is turned Off.

Chilled Water Pump Start Sequence

1. Detect that Pump Start Request is On

2. Select the available pump with the least runtime. If there are no pumps available, take no action and proceed to step 5

3. Start the selected pump

4. Set Pump Start Request to Off

5. Wait 15 seconds (programmable)

6. Restart sequence

Chilled Water Pump Stop Sequence

1. Detect that Pump Stop Request is On

2. Select from running pumps whose HOR status is not in Hand the pump with the most run time. If there are no such pumps, proceed to step 4

3. Stop the selected pump

4. Set Pump Stop Request to Off

5. Wait 15 seconds (programmable)

6. Restart sequence

Chilled Water Pump Manager

Fort Gordon 25910 CEP

25910 Condenser Pumps Start I Stop Sequence

The condenser pumps may be used interchangeably. When starting a pump, the available pump with the least runtime is preferred. When stopping a pump, the running pump with the most runtime is preferred. A pump is available to run if it is currently commanded Off and shows a feedback of Off, it is not marked out of service, its HOR (Hand, Off, Remote switch) is not in Hand, and its Emergency Stop is not active. The pump management software interacts with the Chiller Start / Stop sequence and other control sources through the use of two software points; Pump Start Request and Pump Stop Request.

To start the next available pump, the Pump Start Request is turned On. Once the pump management software has activated a pump, it turns the Pump Start Request Off.

To stop a pump, the Pump Stop Request is turned On. Once the pump management software has stopped a pump, the Pump Stop Request is turned Off

Condenser Pump Start Sequence

1. Detect that Pump Start Request is On

2. Select the available pump with the least runtime. If there are no pumps available, take no action and proceed to step 5.

3. Start the selected pump.

4. Set Pump Start Request to Off

5. Wait 15 seconds (programmable).

6. Restart sequence.

Condenser Pump Stop Sequence

1. Detect that Pump Stop Request is On.

2. Select from running pumps whose HOR status is not in Hand the pump with the most run time. If there are no such pumps, proceed to step 4.

3. Stop the selected pump.

4. Set Pump Stop Request to Off.

5. Wait 15 seconds (programmable).

6. Restart sequence.

Condenser Water Pump Manager

25910 Cooling Tower Operation

Cooling Tower Controls Cooling towers are started and stopped as needed by operators. Cooling tower cell selection is independent of which chillers are operating.

Starting a cell

1. The operator starts the cooling tower fan using the UMCS control or the HOR switch

2. The UMCS detects that the cell fan is on and enables the flow control valve modulation controls for the cell

3. The UMCS modulates the fan speed control to best achieve the Operator entered temperature set-point

4. Drive speed, run status, drive alarm, high alarm, low oil level alarm, and drive selector switch position are monitored, indicated and alarmed by the UMCS

5. Operators may issue an Emergency Stop via the UMCS or by operation of the Emergency Stop pushbutton

Stopping a cell

1. The operator stops the cooling tower fan via the UMCS control or the HOR switch

2. The UMCS detects that the cell fan is off and disables the flow control valve modulation controls which, in turn, fully close the now control valve for the cell.

Fan Speed Controls Fan speed is modulated by a proportional integral control to maintain a condenser water setpoint for each basin. For the east basin, cooling tower fans 1 and 2 (if enabled) are modulated to the same speed. For the west basin, cooling tower fans 3 and 4 (if enabled) are modulated to the same speed.

Tower Flow Control If multiple cooling tower cells are the flow control valve for each cell is modulated to equalize flow to each cell. The differential pressure for each operating cell is averaged into the Average DP calculation. The resulting average is used as the DP setpoint for the flow valve control for each cell. The flow valve for an active cell may not be modulated below 80% open (programmable). If a Single cell is operating, the flow valve for that cell opens to 100% open.

Cooling Tower Bypass Control The UMCS monitors the Condenser Water Supply temperature. If the temperature falls to or below 55* F (programmable) the UMCS opens the bypass valves. If the free cooling heat exchanger is in operation, it overrides this control and forces the bypass valves closed.

Cooling Tower Basin Level Control Level control for the East and West Basins is done with identical but independent controls. For each basin:

1. If the water level drops below the basin level setpoint, open the makeup water valve to 100% open.

2. When the water level exceeds the basin level setpoint by 0.5 inches (programmable) close the makeup water valve to 0% open.

25910 Chilled Water Zone Distribution

Chilled water from the chillers is allowed to recirculate or be drawn into the chilled water zone distribution system pumps. The pumps forward the chilled water to the chilled water zone distribution system.

In the automatic mode the UMCS monitors the zone distribution system differential pressure and controls the pump speed and the number of pumps running to satisfy zone demand. When more than one pump is in operation, the UMCS controls all pumps to run at the same speed.

Zone Distribution Pump Demand UMCS selects the number of pumps to be running at a given time based on the speed of the operating pumps.

· If at least one chiller and primary pump are running, make sure at least one zone distribution pump is running.

· If no chillers and primary pumps are running, stop all zone distribution pumps

· If the pump speed has been above 85% (programmable) for more than 10 minutes. (programmable), Start an additional pump.

· If the pump speed has been below 20% (programmable) for more than 10 minutes. (programmable) and multiple pumps are running, stop one of the running pumps.

Speed Control UMCS monitors the number of zone distribution pumps running and the zone distribution system differential pressure (Zone DP). If the Zone DP is less than the Zone DP setpoint, increase pump speed. If the Zone DP is greater than the Zone DP setpoint, decrease pump speed.

Zone Distribution Pump Start Sequence

1. Verify at least one chiller (or free cooling heat exchanger) and primary chilled water pump are running. Select the available zone distribution pump with the least runtime. If no pumps are available, abort the start sequence.

2. Start the pun-up at minimal speed.

3. Gradually increase pump speed until it matches the speed of the Other running pumps.

Zone Distribution Pump Stop Sequence

1. Select the running pump with the most runtime.

2. Stop the pump.

Hot Water Zone Pump Controls

Hot Water Zone Demand

25910 Deaerator Makeup Water Controls

Pump Selection When starting a pump, the available pump with the least runtime is preferred. When stopping a pump, the running pump with the most runtime is preferred. A pump is available to run if it is currently commanded Off and shows a feedback Of Off, it is not marked out of service, its HOR (Hand, Off, Remote switch) is not in Hand, and its Emergency Stop is not active.

Low Pressure Makeup Water The low-pressure deaerator makeup water System consists of two makeup water pumps, a level Sensor, a high-level alarm sensor, and a low-level alarm Sensor. The preferred method of controlling the tank level is using the output of the level sensor to control the pumps. If the from the level sensor fails, a backup control sequence is implemented using the high and low level alarm sensors.

Control via Analog Level Sensor

· If the water level rises above the shutoff level setpoint, stop all makeup water

· When the water level falls below the start lead setpoint, Start One makeup water pump

· When there is already a pump running and the water level falls below the start lag setpoint, start another makeup water pump

Control via High and Low Level Alarms

· If the low-level alarm sensor is active, start all makeup water pumps

· If the low-level alarm is still active after 60 seconds, signal the high-pressure makeup water system to stop

· If the low-level alarm is not active, clear the stop signal to the high-pressure makeup water system

· If the high-level alarm sensor is active, stop all makeup water pumps

High Pressure Makeup Water The high-pressure deaerator makeup water system consists of two makeup water pumps, a level sensor, a high-level alarm sensor, a low-level alarm sensor, a level control valve, and a stop signal from the IOW pressure makeup water system. The preferred method of controlling the tank level is using the output of the level sensor to control the pumps. If the signal from the level sensor fans, a backup control sequence is implemented using the high and low level alarm sensors.

Control via Analog Level Sensor

· If the stop signal from the low-pressure system is active, stop all makeup water pumps, position the level control valve to 0%, and take no further action until the stop signal clears.

· If the water level rises above the shutoff level setpoint, Stop all makeup water

· When the water level falls below the start lead setpoint, start one makeup water

· When there is already a pump running and the water level falls below the start lag setpoint, start another makeup water pump

Control via High and Low Level Alarms

· If the low-level alarm sensor is active, start all makeup water pumps and position the level control valve to 100%

· If the high-level alarm sensor is active, stop all makeup water pumps and position the level control valve to 0% Low Pressure Deaerator Makeup Water Controls

High Pressure Deaerator Makeup Water Controls

25910 Hot Water Zone Distribution

Hot water from the hot water generators is allowed to recirculate or be drawn into the hot water zone distribution system pumps. The pumps forward the hot water to the hot water zone distribution system.

In the automatic mode the UMCS monitors the zone distribution system differential pressure and controls the pump speed and the number of pumps running to satisfy zone demand. When more than one pump is in operation, the UMCS controls all pumps to run at the same speed

Zone Distribution Pump Demand UMCS selects the number of pumps to be running at a given time based on the speed of the operating pumps.

• If at least one hot water generator is running, make sure at least one zone distribution pump is running

• If no hot water generators are running, stop all zone distribution pumps

• If the pump speed has been above 85% (programmable) for more than 10 minutes (programmable), start an additional pump.

• If the pump speed has been below (programmable) for more than 10 minutes (programmable) and multiple pumps are running, stop one of the running pumps

Speed Control UMCS monitors the number of zone distribution pumps running and the zone distribution system differential pressure (Zone DP). If the Zone DP is less than the Zone DP setpoint, increase pump speed. If the Zone DP is greater than the Zone DP setpoint, decrease pump

Zone Distribution Pump Start Sequence

1. Verify at least one hot water generator is running. Select the available zone distribution pump with the least runtime. If no pumps are available, abort the start sequence.

2. Start the pump at minimal speed

3. Gradually increase pump speed until it matches the speed of the other running

Zone Distribution Pump Stop Sequence

1. Select the running pump with the most runtime

2. Stop the pump

Hot Water Zone Demand

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