Multiple Bilge Pump question...

[roozterdvx]

Is it possible to run 2, 1100gph pumps off of 1 float switch?
I would like to set each one up to run on manual indepenently.

 

[Gary H NC]

Re: Multiple Bilge Pump question...

Sure,I don't see why not if wired correctly..

 

[Silvertip]

Re: Multiple Bilge Pump question...

Not a good idea since there may not be water in both locations at the same time -- hence one will run dry. Otherwise, if you don 't care about the possibility of burning up a pump, it will work. Then there is the possibility that you have water in the area where the float switch is NOT. That pump won't run unless you switched it on manually. If you don't happen to be there, water would collect until it made it's way to wherever the float switch is and then only the amount of water would be pumped out until the switch shut off which may still leave water in the other area.

 

[PondTunes]

Re: Multiple Bilge Pump question...

As suggested above you should take care to mount the pumps where they will both be submerged and protected by the float switch.

If you have two 3 way switches AUTO-ON-OFF and want to be able to run each pump independently you should probably wire it like this.

If you hardwire both of them directly to the float switch both pumps will operate when either switch is turned to the on or auto position. You could isolate one from the other with a diode or two but you would have either one pump running or both running. Using the above diagram and a couple relays you can have full control of either pump.

 

[roozterdvx]

Re: Multiple Bilge Pump question...

Thanx.
I want to mount both pumps at the same level in the bilge. My line of thinking is that if one pump quits on me then the other one keeps on pumping. I have an 1100gph pump there now which is fairly new and figured I could add another one like it instead or going to a bigger pump.

If I end up installing another another float switch, them I'll probably also use a larger pump and set it up as a primary with my current 1100gph as a back-up.

 

[PondTunes]

Re: Multiple Bilge Pump question...

Normally people use the smaller pump as the primary because it requires less power to run, if its only switching on to purge the bilge once in a while it doesn't need to be huge. If you set the secondary pump higher up in the bilge it would only turn on if the primary failed or you were taking on lots of water.

 

[roozterdvx]

Re: Multiple Bilge Pump question...

Normally people use the smaller pump as the primary because it requires less power to run, if its only switching on to purge the bilge once in a while it doesn't need to be huge. If you set the secondary pump higher up in the bilge it would only turn on if the primary failed or you were taking on lots of water.

I hadn't thought of if that way. I guess the smaller pump being the primary is also cheaper to replace and it will see more use/cycles.

The more I think about it, I'm going to install a larger pump for a secondary with a seperate float switch mounted higher than the primary pump float switch. I can mount the secondary pump at the same level as the primary and discharge hose to the opposite side of the boat. That way, if i see water coming out secondary side only, I can switch the pump over to manual.

 

[azlakes]

Re: Multiple Bilge Pump question...

just to add for those who may benefit.. i added a larger bilge pump 1250 from a 550. had a hard time finding a reducer to step down the larger nozzle on the new pump 1 1/8" to the existing 3/4" outlet hose. i dont know how much i gained aside from the "no history, no mistery" factor...

 

[BAYLINER185]

Re: Multiple Bilge Pump question...

How big is your boat?

Just woundering if its left in the water all the time and wounderign if thats why also you want it to run on auto? A bigger pump with and auto on / off switch may be all you really need.

My old Webbcraft took onwater form God knows where and an auto bilge pump would have been nice form when I was camping.

one morning I woke up to find the water in the bilge was just past the oil pan on my motor and my ski locker was completely filled up. While my wife was in the tent I fired up the bilge pump.....asolid 15 minutes later is was pumped dry.

I got to see just how fast my bildge pump pumped that mess out. I never did find out where that water was comming in from.

 

[dingbat]

Re: Multiple Bilge Pump question...

Normally people use the smaller pump as the primary because it requires less power to run, if its only switching on to purge the bilge once in a while it doesn't need to be huge.

Bilge pumps are not there only to pump out rain. They are an important part of your on-board emergency systems. More boats sink at the docks from a failed bilge pump systems than anything else.

You want as big a pump as practical and you want adequate supply of battery power to back them up. If a thru hull fails, your engines cooling system fails, or the hull is compromised in some way you can't get a big enough bilge pump.

If running your bilge pump now and then presents power problems I suggest you rethink your power reserve situation. It could mean the difference of staying afloat until help arrives or sinking.

just to add for those who may benefit.. i added a larger bilge pump 1250 from a 550. had a hard time finding a reducer to step down the larger nozzle on the new pump 1 1/8" to the existing 3/4" outlet hose. i dont know how much i gained aside from the "no history, no mistery" factor...

You've effectively done nothing and may possibly have worsened the situation by increasing the pump and not increasing the outlet size.

If you increase the pump size then you must take the time and effort to increase the outlet size to accommodate the larger pump output. Take the time to install the larger thru hull and hose. Both are easy to come by and are inexpensive as well.

Take the extra ? hour and spend the extra $20 and do it right the first time.