Adding an additional Bilge Pump

[ianybw]

I am about to add another bilge pump, an automatic-switch one to go alongside a manually switched one. The bilge switch has a manual setting and an auto setting.

Is it possible to run them both on the manual setting when threatened with sinking and then switch to auto to use the auto one only ( for when I leave the boat ). How is it wired?

Do I just tee it into the discharge line? Or does it need a separate discharge line to stop me just pumping water back through the idle pump?

They are just Mickey Mouse 12v Rule pumps but appear to do the job.

Thanks in advance, any clever ideas welcome

 

[LadyInBed]

Yes, wire both pumps to the [man / auto] switch, and put a [A off B] switch in the + line of the old pump.

On the [A off B] switch the wire from the old pump goes to the centre connector.
The A side goes to the [man / auto] switch.
The B side goes to +12V via a fuse.

Check the [man / auto] switch current rating is enough to take the current for both pumps.

 

[roly_voya]

Check total current draw if wiring both pumps though the panel an make sure both the panel and the wiring is up to it, you loose quite a bit of capacity if wiring is to small as it drops the V at the pump. I have the Rull 500 and it is very good for keeping the bildge dry as it pumps down to 1/2" and is mounted in a small recess so gets bilge compleatly dry. The wiring is a common neg with seperate man and aut live inputs. I run it directly from the battery with just a fuse so it can't be switched off and then have a simple on/off sw in the man override. Although they are very good for this job I would not even add in the capacity to the emergency pumps, never mind a frightend man with a bucket, a frightend man with a teacup would be more effective. For emergency use you need to be looking at a couple of 1.5" pumps as a min. To give a good idea a 2" pump will just about keep up with the inflow if you remove the log impellor a single wont but will slow the rate of filling significantly. If you cant fit that size electrical go for a couple of decent manual pumps, the 1.5" one tend to be almost as effective as electric and one man can effectively work them.

 

[William_H]

I tend to agree with Roly Voya an auto bilge pump is a good thing in aboat with a stern gland that may leak a little over a period. But for a fibreglass small sail boat with an outboard engine the chances of getting water in are very slim. Any sort of holing disaster is unlikely to be of a leak rate that a small bilge pump can cope with.
A friend has fitted a little Rule bilge pump to his 7.5 metre yacht. It too is o/b powered and he has never had water in the bilge. He just wanted the pump because it seemed the right thing to do and those look pumps look so elegant work so well and are cheap.
Anyway he will never know if the outflow hose is adequate cos he can't test it. ( wIthout bucketing water into the bilge.)
No bilge pump on my little boat just bucket and no concerns since I got rid of the log paddle wheel.
So you need to be sure you need a bulge pump. Secondly you must have a short open overboard hose with little back pressure. So no I would not pair up the outflow with another pump.
olewill

 

[ianybw]

Thanks for the comments.

I dont want to start drilling more holes in the boat and the present pump does the job adequately of mopping up rainfall down the mast.

I have a manual pump as well and if all else fails a bucket.

I think I will just leave it the way it is. If the present pump packs up I can fit this new one, otherwise I will just leave it boxed up in the engine compartment where the wife cant see it.