How to Install a Submersible Sewage Pump: 10 Steps

A good pump can still fail early if it is installed badly. These are the points we send to customers with every submersible sewage pump, in the order you will meet them on site.

1. Check the nameplate before anything else. Voltage, frequency and phases must match the site supply. A 50 Hz pump on a 60 Hz supply, or a 380 V pump on 440 V, will be overloaded.
2. Measure the insulation resistance of the motor with a megger before the first start, and again after long storage.
3. Lift the pump only by its lifting handle or lifting point, with a rope or chain. Never lift or lower the pump by the power cable. Pulling on the cable damages the cable entry seal and lets water into the motor.
4. Stand the pump on a firm, level base, or use a guide rail coupling for larger pits. Keep it clear of the pit floor sludge if possible.
5. If the liquid carries hair, fibres or rags, fit a strainer or choose a cutter pump. Fine fibres wrap around the impeller and reduce performance.
6. Fit a check valve and an isolating valve in the discharge line. A small air relief hole in the discharge pipe below the check valve stops air from locking the pump.
7. Fix the power cable along the lifting chain or pipe so it cannot be drawn into the pump or rub against the pit wall. Our standard cable on many models is 8 m long; tell us when ordering if you need more.
8. Set the float switches so the pump stops while it is still fully submerged. A submersible motor is cooled by the liquid around it. Running dry, or running for long periods with the motor above the liquid, overheats it.
9. Install an earth leakage protection device (residual current breaker) and a motor protection switch sized for the nameplate current. Safety first.
10. On a three-phase pump, check the direction of rotation at the first start. A reversed pump still runs but delivers far less water.

After the first start, check the current on each phase against the nameplate, and listen for vibration or a gravelly noise, which can mean cavitation or air in the pump.