What size Bilge Pumps? 10M Express

Natchamp · Post by **Natchamp** » Fri Jan 13, 2012 8:48 am

Gents,

I need to start planning out what bilge pumps to get for my 10m Express. I've searched the site but haven't found anything specific for the 10m Express and particularly about pump size.

I will have 3 pumps positioned in the stock locations. One in the cabin, one in the engine room, and one in the transom. I also have crash valves on the engine seacocks as an fyi.

So, aside from the largest possible, what are good pump flow sizes for the 3 pumps? Also, should the largest pump be in the cabin since that's the lowest pump of the 3?

Thanks for any insight.

Allen Sr · Post by **Allen Sr** » Fri Jan 13, 2012 4:43 pm

Personally I would put in 3 1500gph if your discharge lines will hook up to them.

Vitaliy · Post by **Vitaliy** » Fri Jan 13, 2012 7:54 pm

i dont know what your shooting for but my f36 has two 2000 GPM Rule pumps which are more then enough and are about the same price as the 1500, and i also wired in a 3800 as a standby just incase (i already had it so no point of it going to waste)

Torcan · Post by **Torcan** » Fri Jan 13, 2012 7:59 pm

Just get bigger buckets

RWS · Post by **RWS** » Sat Jan 14, 2012 7:12 am

mine had 3 1500 gph pumps when I got her.

added a 3500 emergency pump to the engine room, mounted the pump & switch higher than the factory unit.

Wired that one into the genny circuit - it's totally independent of the others.

Re-attached the emergency horn system back into three new bilge pump switches.

While the fuel tank was out we cut out a section of the aft liner to get that pump lower so it could get more of that water out of the boat.

RWS

RWS · Post by **RWS** » Sat Jan 14, 2012 7:58 am

Having that "emergency" pump on a completely seperate battery system was important to me.

When I got the boat there was a battery strap to connect the genny battery to the port battery so it coule be charged in tandem from the alternator.

I disconnected that leg and installed a battery switch to allow for isolation of that genny battery.

In the event everything goes down, there's always that emergency 3500 pump attached to it's isolated power system.

That factory horn alarm system is a very nice feature.

RWS

Vitaliy · Post by **Vitaliy** » Sat Jan 14, 2012 10:55 am

hmmm a high water alarm.... not bad, might have to consider that one, when i purchased my boat the previous owner had this strip sensor attached right below the ac that was supposed to be the high water alarm however after pouring a bucket of water on it nothing happened so we tore it out (probably bad) so i might have to find one of those and install it

Big D · Post by **Big D** » Sat Jan 14, 2012 11:20 am

+1 RWS, having all your pumps wired to the same power source is not a good idea. Spreading them to different banks reduces the chances of them all failing at once due to power source or circuit failure. You can never have too many redundant safety systems IMO. Wiring the horn to the high water pump circuit is a must in my books. The more attention you can bring to a sinking ship, the better the chances that someone can take action to prevent disaster.

The large pumps are great for volume. If adding one to existing wiring however, you will deminish the pump's pumping capacity and sacrifice safety if the wiring isn't sufficient to accommodate the larger pump's electrical load. Aside from the safety issues, you can conceivably reduce the rated volume of a 2500 GPM pump to 2000 or much less depending on the wire used. Kind of defeats the purpose of trying to keep her afloat but setting her ablaze in the process. Don't cheap out on the electrical hardware!

Big D · Post by **Big D** » Sat Jan 14, 2012 11:37 am

Vitaliy, there are several devices and rigs you can make up to trigger a pump but a regular float switch is probably your best/easiest set up. There is more exotic hardware available but the floats work just fine if maintained right. The high water one won't get any action unless there's an emergency and as such should be checked for proper operation at the start of every season at least. All floats should be checked.

RWS · Post by **RWS** » Sat Jan 14, 2012 12:31 pm

My 10 meter came with three factory bilge pumps & float switches.

Additionally the factory high water alarm system wired into the horn relay has it's own three additional float switches with the appropriate markings.

I added a manual override switch in the cabin to kill the horn in the event it should become necessary.

RWS

Big D · Post by **Big D** » Sat Jan 14, 2012 12:38 pm

RWS, did the expresses and that vintage of Trojans originally have all the pumps wired to the same bank?

RWS · Post by **RWS** » Sat Jan 14, 2012 5:47 pm

It appears that they split the system..

The two main breakers for the bilge pumps are wired to port / starboard.
Nice, well thought out system.

RWS

alexander38 · Post by **alexander38** » Sat Jan 14, 2012 9:10 pm

then you could always plum your raw water pumps in as crash pumps\, bucket list...RWS did hit on a good ideal to use the gen battery for the back up pump...

captainmaniac · Post by **captainmaniac** » Sat Jan 14, 2012 9:13 pm

Big D wrote:Vitaliy, there are several devices and rigs you can make up to trigger a pump but a regular float switch is probably your best/easiest set up.

And float switches should have a cage over them to prevent anything that is in the bilge from interfering with the switch's mechanical operation. If something floats or rolls under the switch it can jam it on (draining your battery or burning out the pump) or off (making it ineffective).

Had a friend with a SeaRay 36 Aft Cabin - on one trip while out and running his wife went down into the aft cabin for something and found 2" of water above the floor. Getting water in the bilge was 'normal' (accumulation from rain runoff etc) but was normally evacuated by his float switch activated aft pump. But the pump never kicked in because a coil of wire that was bouncing around in the bilge had landed on top of the float switch and had it pinned down.

Big D · Post by **Big D** » Sat Jan 14, 2012 11:49 pm

+1 to that captainmaniac. I like it when I come across pumps and switches that aren't even fastened down.