Rule bilge pumps running in reverse

[sKooTr]

According to the data sheets for the Rule bilge pumps (http://www.mackengineering.co.uk/produc ... %2025D.pdf), when they are operating in reverse they only work at 20% compared to operating in forward. This raises a few questions for me ...

- Can someone confirm this is true?
- Can they be easily modified to allow 100% in reverse?
- Are all models like this?
- Can someone recommend another brand that doesn't work like this?

Thanks.

Scott

[thegadgetguy]

I think that what that means is not that the pump turns at 20% the speed if you reverse the polarity, but that the pump will pump at 20% of the original speed. The impellers inside these things are only really meant to turn in one direction and pump water, so if they're turning the other way, then they aren't going to pump efficiently at all, which would cause the 80% reduction in water flow.

If you are using propellors on your pumps, then you shouldn't have a problem. Steve has never mentioned any problems like this, and he is using Rules. The main problem with propellors is most propellor designs don't work as well in reverse.
If you are just using the pumps as pumps, make sure the polarities are correct.