MCE600 does not start after switching off power to pump

Question:

The pump on my MCE600 skimmer does not restart after a power cut or if I manually switch it off and back on. The suction pipe is still full of water when I restart it and I have tried closing the tap which does not make a difference.

Strangely if I remove the pump from the skimmer body and run it in the sink then it starts first time or if I pull the pump back out of the suction pipe then it also starts.

Answer:

On the new design 2008 Aquabee pumps, the ceramic shaft is glued to the impellor and supported by two ceramic bearings at each end. When assembled correctly the bearings and the shaft/impellor are in perfect alignment and run with negligable resistance to the rotation of the impellor.

If the pump does not start when it is fitted in the skimmer but does start when it is not then this is normally a sign that the end suction plate is not fully home on the pump and is fitted twisted. This can cause the ceramic end bearing to sit at an angle out of line with the shaft which may create enough resistance to prevent the rotor from passing the crutial 180 degree mark so that it is picked up by the opposite winding, allowing full rotation to occur. Once there has been more than one revolution the inertia of the impellor ensures that it continues to rotate freely.

To fit the suction plate correctly it should be given a gentle tap at the end to ensure that it is fully square and in position against the pump body before tightening the cam ring. If this is done as described the ring turns easily whereas if it is not done then it is much stiffer to turn as it is having to force the suction plate down.

If the plate is not fully home when it is pushed into the suction pipe of the skimmer body, especially if the suction pipe itself is slightly misaligned, the suction plate may become twisted and a resistance to the starting rotation may occur.

Remove the pump and reassemble.

Stuart