Lake Bolac Booster Pump Station

The Purpose of the Lake Bolac booster pump station project will be to construct a new clear water storage tank with attached booster pumps within the township of Lake Bolac. The new tank will be used to improve the reticulation pressures and improve supply security.

Lake Bolac’s reticulation is currently fed from Willaura Water Treatment Plant’s storage at Mt Pleasant through 13km of DN150 AC gravity pipeline. This existing gravity system is to be used to feed the new clear water tank in Lake Bolac. The booster pumps will then supply Lake Bolac’s reticulation network with pressurised mains water.

birds-eye

 

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The Operator Interface has the following features :

Monitoring and control of the pump station is performed by a  SCADAPack ES RTU unit and Operator Interface Panel (HMI).

Status and parameter values are gathered by the PLC via this network for display on the HMI and SCADA screens.

The parameters monitored are –

  1. Pump power – kW and kVA for each pump
  2. Total pump station power – kW and kVA
  3. Operating and fault data from the Main Pump VSDs.

The Clear Water Storage (CWS) tank at this site is gravity fed from the Mt Pleasant tank through the existing  supply pipeline.

An inlet control valve assembly cotrols the fillig of the Clear Water Storge tank.

The control assembly consists of an inlet pressure transmitter, a flowmeter, a solenoid control pressure sustaining valve. The pressure sustaining valve (set to 22m head) is normally closed and opens based on tank level if the upstream pressure is sufficient to ensure supply to customers connected to the main pipeline.

The flowmeter monitors the difference in flow between the Mt Pleasant outlet and Clear Water Storage tank inlet to ensure it is within the expected limit. If this limit is exceeded, an alarm is sent to operators through SCADA to indicate a  break in the supply mains.

A level transmitter is installed within the tank and is be used to monitor the tank levels. The level transmitter is backed-up by high level and low level float switches to enable the station to operate should the level transmitter fail.

The high level float is used to esure the inlet valve is closed. The low level float is used to ensure the pumps are turned off.

Under the low level condition, the system utilises the bypass valving arraangement (within the pump station building) to supply the town.

If the water level drops below a pre-determined ‘low level’ or the water level rises above a pre-determined  ‘high level’, the respective alarm is sent to operators through SCADA.

The system must then utilise the bypass arrangements to supply the town.

Booster Pumps and Bypass Valve

booster-pumps-and-bypass-valve

The inlet valve installed on the tank inlet pipework assembly to allow the system to bypass the tank and booster pumps during power failures.

The pipework within the pump station building is shown above.

The discharge manifold for each booster pump is fitted with a non return valve, and a flow monitor.

The commoned discharge manifold is fitted with a pressure gauge, a pressure transmitter and a high pressure switch.

The pressure transmitter continuously measure the pressure within the reticulation network.

The pumps must be  configured to turn on and operate when the pressure in the reticulation drops below a 65m (operator adjustable like all settings).

Once the pressure in the reticulation increases to the  desired level, the pumps must turn off. If the discharge pressure exceeds a predetermined high pressure level, the operating pumps are stopped and an alarm is raised.

The pressure switch resets itself when the pressure reduces to an accepted level.

(The latch which stopped the pumps is however not reset when the switch resets. The latch needs to be reset by an operator, using the Reset button on the HMI Overview page.)

The chlorine analyser in the pump station monitors the free chlorine and total chlorine levels in the water supply pipeline. The analyser is connected to the RTU unit to monitor the chlorine levels and alarm operators when the chlorine level is not within the approved levels.

Electrical Power Systems

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Electrical Supply to this site is provided from a ?? kVA pole mounted transformer via pole mounted ?? A Supply Authority Service Fuses.

The 415 V 3-phase power is fed from to the pump station meter panel mounted on the outside of the building.

The metered power is fed to a manual transfer switch (MTS) acting as the site “MAIN SWITCH”

The MTS is a mechanically interlocked switch with two operating handles.

Power source can be selected as being from either MAINS SUPPLY or GENERATOR SUPPLY.

A generator panel is mounted on the outside of the pump station building to facilitate temporary generator connection should the need arise. A terminal strip is provided within this panel for generator status connections.

 

Main Switchboard

The main switchboard houses the motor starters for the pumps, 24 VDC supplies and distribution, and common controls for the pump station.

lake-bolac-board-drawing

Booster Pump Control

For normal operation, the booster pumps operate under PLC/RTU control based on demand for maintaining adequate discharge pressure and flow. The pump selector switch for eah pump must be set to   “ON”.

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Each pump can be operated manually by setting manual mode via the VSD keypad (which can be seen below).

The pump speed can then be set by the respective pump VSD keypad. The keypad can be used to start and stop the pump and increase / decrease the pump speed.

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Pump station building

 

site-diagram

Pump station building layout

 

site-layout