PROJECT: Off Grid Pumping Station
Grey Water Lift Pump + Rain Water Circulation Pump
Irrigation pumps (12V DC /65PSI) and water tanks. Off the grid solar powered remote PLC control panel with wireless modbus communication.
Design and build two pump control panels to control the potable rain water supply, and provide a reliable grey water recycling and dosing system for the w.c cisterns along with the ability to redistribute all excess grey water to a remote off the grid irrigation pump station with holding tanks.
The remote irrigation control panel and pumps would need to distribute the excess stored water periodically to the irrigation gardens or to the greenhouses. The ability to wirelessly communicate between the master control panel/pump station and irrigation control panel/pump station is essential to maintain a control loop and to receive trending and alarms. Trending on all tank levels, tank temperatures, pump run times and events and alarms logging was required.
We designed and built two individual control panels. The master control panel would automate the primary pumps. First, we designed a simple "independent" PLC control system using a Zelio PLC smart relay controller to monitor the rain tank water level and temperature. The rain tank circulation pump automation is controlled by a tank level pressure transducer and pump pressure transducer respectively. End user rain water demand would operate on pump pressure drop...eg when a tap is opened.
The next step was to install and program an additional Zelio PLC smart relay controller in the same control panel for the grey water system. Again, we used the basis of this rain tank/pump program for a second simple "independent" control system to monitor and automate the grey tank lift pump for w.c cistern water demand and high level water diversion. We added PLC logic for the w.c cistern dosing. The grey water level is maintained by an ultrasonic level sensor at <65%. Water above this level will trigger the grey water irrigation valve to open and diverts the excess grey water to the remote irrigation holding tanks and pumping station.
We designed and automated a simple filter backwash cycle followed by a grey pump suction line purge to be performed at the end of every grey pump off cycle. This was done by momentarily changing the VSD speed from 50Hz to 60Hz to maximize stored water pressure in the pressure tank, post pump cycle, in anticipation of the imminent backwash cycle. This was able to provide an extra 20% pressure gain resulting in 85-90 psi for the backwash water pressure. This pressure is dissipated within 5 seconds, through the filter and is necessary to perform the filter backwash thoroughly. The pressure drops post backwash to 22 psi at idle, so risks of leaks are very low. The backwash system has extended the filter maintenance schedules significantly to provide a reliable grey water system.
We designed and built a second control panel for the remote irrigation pump and tank automation. We wrote a dedicated program for a third simple Zelio "smart relay" PLC controller to automate the off the grid irrigation pumps on timed outputs throughout daylight hours. A diversion valve was added to alternate (or divert excess) irrigation tank water to the greenhouse/gardens.
All independent PLC systems were programmed to monitor water levels and temperature, low tank alarms and inline flow switches were incorporated to prohibit pumps running dry. Low pump pressure PLC logic was added to the programming as a precaution for the pumps.
All three independent PLC's were networked back using Modbus serial RTU to a master PLC with a custom HMI solely for monitoring, secondary control and alarms and events trending. We configured a wireless transceiver RF (radio frequency) modbus RTU network for the irrigation pump station for remote local PLC network communication. Global monitoring and control is achieved from the ethernet network port on the HMI to the world wide web via a smart phone/device.
Rain Water Circulation Pump + Tank Level monitoring and control using a Zelio smart relay PLC and HMI.
Grey Water Pump + Tank Level monitoring and control using Zelio smart relay PLC / HMI.
Master Grey Lift Pump and Rain Circulation Pump control panel with two Schneider Zelio PLC controllers, automating two pump VSD's. The Schneider Modicon M221 Master PLC is networked back to a local HMI panel. The HMI has a VPN ethernet TCP/IP communication connection for internet remote access, and end user monitoring and control.
12VDC Solar off the Grid Irrigation pump control panel with a Schneider Zelio PLC and wireless RF Modbus transceiver Modbus communication
HMI - Smart Phone duplication of our Harmony HMI Irrigation pump and water tank monitoring
HMI -Smart Phone HMI monitoring of our Grey Water Pump and Tank displaying a filter backwash .
Schneider Zelio SR3B101BD PLC modules for the pump stations control and automation.
Schneider Modicon M221 PLC as the master controller to communicate between all three Zelio PLC's.
Schneider HMISTU-655 Magelis HMI for the monitoring, control, trending and remote ethernet access.
Ebyte Modbus RTU wireless 5KM range transceivers for wireless network communication.
Altivar 3-Phase VSD for pump control.
Grundfos 3 Phase Vertical Multistage Pumps
12VDC Off Grid Pumps
Solar Panels and controller for Off Grid Pump Station.
Actuator valves, non return valves and a pressure tank to provide the automation of the grey pump filter backwash and suction line purge.
Irrigation Water Pump + Tank Level HMI monitoring using Zelio PLC and RF radio frequency modbus transceivers for wireless communication back to the Modicon M221 master PLC controller.