Stormwater lifting station control panel, Al Hamra Zone 2

About this project

A stormwater lifting station at Al Hamra Zone 2 needed a control panel for two 90 kW pumps running duty and assist. Both pumps are driven through variable frequency drives, and the whole panel had to comply with Etihad Water and Electricity regulations and specifications rather than a generic panel standard.

Duty and assist is a different problem from duty and standby, and it is worth being precise about the difference. Duty and standby means one pump runs and the other waits. Duty and assist means the second pump joins the first when inflow demands it. On a stormwater station that distinction is the whole design, because the station is idle most of the year and then has to take a storm inflow without either pump short cycling or the wet well overtopping.

That is why the level measurement is doubled up. A hydrostatic level sensor gives the continuous reading the drives modulate against, and four float switches sit behind it as discrete backup at fixed levels. If the transmitter fails during a storm, which is exactly when it matters, the floats still start the pumps.

The panel interfaces to the pump manufacturer's IO113 and SM113 modules, which carry the motor's own protection and condition signals, including winding temperature and moisture in the motor. Bringing those into the control system rather than leaving them as local trips means the station reports why it stopped, not just that it stopped.

The enclosure is GRP and weatherproof, because a lifting station panel stands outdoors on a drainage reserve with no building around it. A GSM link provides remote monitoring, and the panel was built ready for integration into the authority's SCADA as a separate step.

The completed MCC went through factory acceptance testing before it left the workshop, and handover included as built drawings and a warranty certificate.