Bilge Pump Placement

[Chop~Chop]

I've look at a few posts on pump'n switch upgrades and for the life of me I can't figure out why my setup is as shown...

It may be difficulct to see in the photo; the float switch is lower in the bilge than the pump. :?

Is there any rationale for this?

I reviewed Megabyte's project:
http://www.classicparker.com/phpBB2/viewtopic.php?t=64

I'm not clear of the alternatives on how a "backup" pump could be wired.

 

[TomS]

Chop-Chop,

Not sure I see a problem. Its hard to tell, but I'm assuming thats a float switch? Just think how high the water level must be in order for the switch to get triggered, looks like it would be above the level of the pump base.

-- Tom

 

[MaxOut]

On your back up pump I would run it threw a float switch directly to the battery with a fuse at the battery. Do not use any existing pluming or wiring. Waterproof all connections including the fuse holder. Use Marine grade wiring that is designed to be submerged. Add a new through hull for the discharge beside your existing or on the opposite side of the boat. As an added option you could put a switch in to bypass the float switch in case it fails (they often do). Rule of thumb is on any emergency electronics is to keep the wiring as short as possible, as few connections as possible and wire hot and ground directly to the battery. Your current pump and switch location is fine

 

[DaleH]

Not sure I see a problem either. First off, that pump isn't going to pump down to the level of the piece it's mounted on, and will probably only pump down to 2" above that piece. What you wouldn't want is for the float switch to tell the pump to run when there's no water at the pump.

My 2200gph storm pump is fully manual - chosen & wired so for reliability - using a simple On/Off switch. Thus I run a high water alarm in the bilge that is tested before every trip.

 

[Megabyte]

One way to find out if the switch is positioned properly is to put a hose in the bilge and turn the water on to make sure it'll work as designed.
Gives you a good excuse to wash and flush the bilge.

As you saw in the link to my post, I found out the hard way on my neighbors Whaler. The switch cannot be below the intake on the pump or the switch will never turn off.

I have had people in the marine industry who's opinions I trust, that caution against putting an inline fuse on a bilge pump. Engineering a point-of-failure in a safety system doesn't make sense to some folks.

It is one of those passionate subjects that have fans on both sides of the issue. :wink:

 

[Jersey Jim]

Engineering a point-of-failure in a safety system doesn't make sense to some folks

One should always install an inline fuse with a rating such that the fuse will melt before the wiring does. For example, if the bilge wiring will withstand 10 or 15 amps before achieving high enough temperatures to melt it's insulation, then a 10 amp fuse SHOULD be installed. Especially if the normal operating current of the bilge pump is only 3 amps or so. In the unlikely event that the pump is found to be drawing 10 or so amps, then something else is terribly wrong and the pump will most likely be jammed, not spinning or pumping anyway. There is no point risking an electrical fire, and continuing to draw massive amounts of power from a battery that could be saved for a redundant and functioning system. However, I would also avoid fusing such a safety system on a "hair-trigger" with a fuse rated close to the normal operating current. Also, If a device's normal current draw is close to the capacity of the wire, then heavier gauge wiring should have been used.

Somewhere on this board someone posted a handy wire-capacity calculator for those who need to determine the safe current-carrying capacity of various wire gauges. I also recommend first measuring the pump's normal current being drawn before deciding to allow a double, triple, etc. trip-point.

 

[DaleH]

I believe it is the opine of Mr. David Pascoe, a marine surveyor of some reknown, who advises - for STORM PUMPS only - that they be wired direct to the battery WITHOUT any fuse protection.

The theory (his opine only ...) is that he'd rather take the chance the pump will cycle until failure of the pump or wiring ... and risk any chance of fire ... versus dealing with a sinking boat and potential for a clogged pump to blow a fuse. Then you're stuck with a sunk boat ... though clearly no fire .

I will say, for EMERGENCY purposes only, I can't disagree with his reasoning.

What I did ... my 2200gph STORM pump is mounted 5" above the standard stern bilge pumps (yes, I am redundant) and it is on a manual switch, as I only intend to turn it on if & when the high-water bilge alarm sounds. I also upped the recommended fuse rating for that run and sized it to the ampacity of the wiring run itslef (not the pump rating). This run is also fairly short, as it was battery to fuse to switch to pump, probably all less than 9' one way.

 

[MaxOut]

Engineering a point-of-failure in a safety system doesn't make sense to some folks

One should always install an inline fuse with a rating such that the fuse will melt before the wiring does. For example, if the bilge wiring will withstand 10 or 15 amps before achieving high enough temperatures to melt it's insulation, then a 10 amp fuse SHOULD be installed. Especially if the normal operating current of the bilge pump is only 3 amps or so. In the unlikely event that the pump is found to be drawing 10 or so amps, then something else is terribly wrong and the pump will most likely be jammed, not spinning or pumping anyway. There is no point risking an electrical fire, and continuing to draw massive amounts of power from a battery that could be saved for a redundant and functioning system. However, I would also avoid fusing such a safety system on a "hair-trigger" with a fuse rated close to the normal operating current. Also, If a device's normal current draw is close to the capacity of the wire, then heavier gauge wiring should have been used.

Somewhere on this board someone posted a handy wire-capacity calculator for those who need to determine the safe current-carrying capacity of various wire gauges. I also recommend first measuring the pump's normal current being drawn before deciding to allow a double, triple, etc. trip-point.

I agree Jim :wink: - a burnt motor can melt inside putting a direct short on the circuit and something is going to give. I do not know of any manufacturer who does not put a fuse in the bilge pump circuit or any other safety circuit including our precious Parkers. I have engineered many electrical systems including those on boats and safety is priority one. I don’t look at a fuse as a possible failure point I look at it as an additional safety point (redundancy).

What would you rather have next to your boat at your marina a sunk boat or a burning one? Just my opinion.

 

[96TL]

I fused both of my bilge pumps. Keep the stainers clean, keep garbage out of your bilge, waterproof all the connections, and you should be okay. Make sure you use a fuse rated for your bumps electrical draw. 8)

I have two Johnson 2200GPH storm pumps with WaterWitch electronic switches and a WaterWitch BA200 bilge monitor.

 

[Chop~Chop]

Thanks for the insights on back-ups.

But some time ago once I did notice the pump did run dry while the water level was high enough to maintain the float switch switched on. One little tap of the switch, the pump would turn off. Since most all rain water goes out the scuppers and most unmonitored water ingress ends out accumulating in the forward bilge anyhow, I had decide to leave well enough alone...until now.

I looked more carefully at how the pump and blue float switch got mounted. The glassed-over wooden mounting pad is not big enough to accommodate the width of the switch and the diameter of the pump to allow them to be placed near about the same level.

It appears it was decide to allow the pump to potentially run'n run rather than allow excessive water to accumulate before the float switches. I would have opted for the later, given what there was to work with during install.

Notice in Kevin's more recent post, I think the Megabyte's mounting block is an inch or two wider than mine; it appears to be about only one finger's width from the transom.
http://classicparker.com:80/phpBB2/view ... ight=bilge
Chop-Chop's block has a good two fingers width clearance.

I want to mount the primary pump as Kevin did; can you explain how you secured the pump essentially centered?
Looks like I will end out with a small space, maybe 0.5" between the hull and the pump base, but that's probably ok?
I don't think there is really any need to have the pump base caulked with a polysulfide adhesive to the pad and then socked down with four #8 screws, one or two would do?

Thanks, Mark

 

[Megabyte]

can you explain how you secured the pump essentially centered?
Looks like I will end out with a small space, maybe 0.5" between the hull and the pump base, but that's probably ok?

I don't think there is really any need to have the pump base caulked with a polysulfide adhesive to the pad and then socked down with four #8 screws, one or two would do?

No problem Mark... Here is how I did mine.

My primary pump (aft) is situated as low in the hull as I could get it, which essentially means that it does not completely ride squarely on the mounting block.

The pump was slid over to port until the outside (port side) edge of the strainer contacted to the rise of the hull on the port side, putting it as low in the hull as possible. Positioning it this way allows the stbd side of the pump strainer to remain in contact with the pad, and the pump is attached to the pad with 2 screws.

Although the screws are bedded in 4200, you don't need to glue the strainer down with 5200 and 4 screws in order to keep it in position. Two screws are plenty.

Before I completed my mounting, I mocked up the entire assembly to make sure that my discharge hose was in the correct position, and I would be able to pop the release clips between the pump body and the strainer to check for FOD, or to clean as needed.

Mocking it up before also showed me the eventual positioning of the WaterWitch 101 so I could decide if the screw clamp mount or the nylon zip tie (on the body of the pump) would give me a better mount.

My whole purpose in mounting mine the way I did was to allow the primary pump to evacuate the maximum amount of water possible.
Once the primary pump was mounted, I did the same with the backup pump.

In the project post you referenced, I still had the MSC switch on my backup pump. That switch was replaced this past winter (as was the forward bilge switch) with WaterWitch switches.

The switch on the backup pump is adjusted 2" above the high water mark for the primary switch. That is, it is 2" above the level where the primary pump activates. I adjusted the backup pump switch in this manner so it is not affected under normal conditions, but will not allow excessive water to accumulate in the bilge in case the primary pump fails.

Hope the helps!

 

[Chop~Chop]

Roger, WILCO.

The mockup is essential, thanks Kevin.
Allot like soldering two wires together; make a good stable mechanical connection with tinned wires first then a little heat is all you'd really need.

Today I completed the disassembly, aka demolition. It's always seems to be three steps forward, one backwards; but it's fun
It may be difficult to see in the picture but there is a fracture in the housing where it is molded to form the 1.125" outlet.
You might also even notice, there's some caulk on the outlet. I'm not sure that's necessary?

I can't believe I was really strong enough to tear the whole freaking thing of the apart. It's my sense the clamp got socked down with one of those 5/16" nut drives on an battery powered drill with the torque max'd out...I don't think 5200 was used to weld the pump strainer to the pad; it came up fairly easily.

To seal the 4 wounds left from the strainer and the 2 from the float switch, what would one use, 52/4200 or an epoxy putty?

I'm eyeing the Magnum 2200 from these guys to use as backup and if I can figure how to tack-in the Attwood's Sahara 750 or the little Rule 1100 as primary it looks like they could sit nicely.
http://www.wholesalemarine.com/mm5/merc ... e=33000002
They seem like an ok source...all the other yellow pumps are Johnson's too. There's a convoluted story about Johnson buying-out Mayfair...

When the strainer was attached, were custom holes created in the strainer and was the screw driven not perpendicular to the pad, but into its edge?
I think that could work ok especially if I use a shorty.

Thanks Again, Mark

 

[TheOtherLine]

I am thinking about ADDING, not replacing a bilge pump.

A friend of mine says he has 3 pumps. One that automatically pumps when it senses water, another one that he can turn on with a switch to help the first one and a 3rd bilge that pumps 3 godzillion gallons per second ( I made that up, but it was a lot ) that just has alligator clips that he can connect to a battery if the other 2 systems fail for whatever reason.

I found this interesting. He also said the exhaust hose and fitting are 3", to allow it to disperse as much water as possible as quickly as possible.

Does this 3rd bilge setup sound like a reasonable back up? It would be a backup to my stock bilge pump. If so, any tips on where I should drill into the boat? Should it be on the same side as the existing hole?

 

[DaleH]

FWIW I have 2 pumps in the stern, 1600 and 2200gph models. The smaller is auto, the larger is on-demand ... a 'storm' pump.

I put them out one on EACH side of the boat, so in case she heels, 1 pump can always dewater the boat.

 

[Megabyte]

I also have 2 pumps in the stern. Both are 2000 gph Rule and each is wired to a separate battery. The rear pump is the primary and the forward pump is the backup. Both pumps have a manual over-ride.

My midship bilge pump was originally a 360 gph pump, but I upgraded it to an 800 gph pump. With 4800 gph of capacity I can only hope that the motor keeps the batteries up.

 

[TheOtherLine]

Dale, Kevin, due BOTH of your pumps exhaust through ONE thru hull opening? Any need to cut another hole for a separate exhaust? Also, am I seeing that the backup does NOT have a float?

 

[Megabyte]

Dale, Kevin, due BOTH of your pumps exhaust through ONE thru hull opening? Any need to cut another hole for a separate exhaust? Also, am I seeing that the backup does NOT have a float?

My pumps both exit through their own through hull.

My bilge pumps use WaterWitch electronic sensors. No floats...

 

[TheOtherLine]

OK. And Dale already said he has his on opposite sides so, you both are running separate exhausts. Kevin, I saw your water witch. Thanks.

I do like the alligator clip idea though. Am I missing something?