Submersible Sewage PumpsStarting Large Submersible Pump Motors: Four Methods Compared
Direct-on-line, star-delta, soft-start and VFD starting compared for 45-250kW submersible sewage pump motors, with the trade-offs that actually matter on site.

Model: WQ/QW
Custom-voltage WQ/QW submersible sewage pumps supporting 400V, 415V, 480V at 50 or 60Hz for overseas municipal and industrial tender projects.
| Flow Rate | 5 – 1200m³/h |
|---|---|
| Head | 5 – 60m |
| Power | 1.5 – 160kW |
| Inlet / Outlet Diameter | DN50 – DN300 |
| Material | Cast Iron,SS304,SS316L |
Most export orders aren’t running on standard 380V 50Hz. They’re matched to whatever the destination site actually supplies, and that’s what custom-motor manufacturing is for. 400V, 415V and 480V at either 50 or 60Hz are all realistic across the WQ and QW range, with no change to hydraulic performance; only the winding parameters shift to suit the target voltage and frequency.
One planning detail matters for EPC and tender teams specifically: the final performance-curve document is only issued once the motor spec is confirmed, so custom orders take longer to document than stock units. Raising the voltage and frequency requirement early in the RFQ process, rather than late, is the difference between this being a minor scheduling note and a bottleneck near the submission deadline.
Submersible Sewage PumpsDirect-on-line, star-delta, soft-start and VFD starting compared for 45-250kW submersible sewage pump motors, with the trade-offs that actually matter on site.
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