Irrigation Mains at Khalifa City “A”

About this project

The irrigation mains at Khalifa City A are served by five pumping stations distributed across the district. Almafor delivered the electrical and control scope for all five as a specialist subcontractor to the municipality's programme.

Each station received a Form 4 motor control centre, a PLC, an RTU and HMI touch screens, with fifteen variable frequency drives across the pump sets. The split between the two controllers is deliberate and it repeats across our pumping work: the PLC runs the pumps and the local sequence, and the RTU owns the conversation with the outside world, holding data when the communication link drops so the record has no gap once it recovers.

Form 4 was specified for the motor control centres because the stations have to be maintained without being shut down. Form 4 separates the busbars, the functional units and the outgoing terminals from one another, so a single starter can be isolated and worked on while the rest of the board stays live. On a station feeding a district irrigation network that is the difference between taking one pump out of service and taking the network off supply.

The variable frequency drives do two jobs. They soften the mechanical and hydraulic shock of starting a pump directly on line, which extends the life of the pump and the pipework, and they let the station match delivery to demand rather than cycling pumps against a fixed duty.