240 volt 'bilge pump'

WhatHove

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240 volt \'bilge pump\'

I've got an engine driven bilge pump to take care of emergencies on my boat. I want to add an electric back up that will run off my 750 watt onboard generator or shore power. As it is for emergency use only, I was thinking of getting a 240 volt submersible pump from the likes of Machine Mart. Has anyone got any experience of using pumps like this http://www.machinemart.co.uk/product.asp?p=051019145&r=2163&g=122 in salt water? It would only get wet when it was being used and I like the 300L/Min capacity - boaty ones with similar output cost a lot more.

Does anyone have any better ideas that don't involve frightened crew and buckets?

Thanks
WH
 

cliff

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Re: 240 volt \'bilge pump\'

I have a FRP bodied version which works well for MAJOR flooding. I would need about 8~10" of water to get the float switch to work as it needs to float level with the top of the pump or even higher before it will trip. As the water level falls the switch cuts out generally with 3~4" of water remaining. One solution is to lift the switch up and invert it, the pump will then suck down to about ¼" of water.
The pump take quite a starting load but runs happily of an 1800w inverter.

I do not carry the pump anymore as I changed boats and I no longer have anywhere to mount such a large pump. I rely on a number of smaller pumps backed up by a couple of manual pumps. If I am shipping that much water it is time to take to the life raft!

In conclusion the answer to your question is yes it could be made to work but you need to ask yourself do you really need it and the associated hassle - as a point of interest, do you consider it a good idea to leave 240v equipment LIVE and lying in the bilges?
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WhatHove

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Re: 240 volt \'bilge pump\'

Thanks Cliff,

With regard to your point about 240V in the bilges, I'm not really sure. The pump and cabling is clearly designed to be submersible, and if I did have it connected to shorepower the connection would be properly protected. I'd check the cable run regularly, of course.

What would your concerns be? I guess from your post you wouldn't much like it - but I was really thinking more of running it from the genny at sea in an emergency.

So was your FRP pump affected by salt water in any way over time - did it get submerged in seawater often, and can you remember the type/brand?

Cheers
WH
 

pvb

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Only problem...

I have a couple of similar pumps which I use in the garden. The only problem with them is that they rely on being covered by water for their cooling. If you try to use them in circumstances where there's only an inch or so of water, they'll overheat and cut out. Once they cut out, it takes quite a long time for the thermal cutout to reset itself (and it can't be manually reset).

These pumps are usually double-insulated, and you shouldn't have any safety problems with them. I wonder whether you'd be safe to run a small generator at sea though - especially in an emergency.
 

cliff

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Re: 240 volt \'bilge pump\'

[ QUOTE ]
Thanks Cliff,

With regard to your point about 240V in the bilges, I'm not really sure. The pump and cabling is clearly designed to be submersible, and if I did have it connected to shorepower the connection would be properly protected. I'd check the cable run regularly, of course.

What would your concerns be? I guess from your post you wouldn't much like it - but I was really thinking more of running it from the genny at sea in an emergency.

So was your FRP pump affected by salt water in any way over time - did it get submerged in seawater often, and can you remember the type/brand?

Cheers
WH

[/ QUOTE ]No, Yes and it came from Screwfix for circa £30.

AS for the power situation i just asked if you would be happy with 240v in your bilges - I have noithing against it as the pumps are double insulated and I have RCBs on the 240v circuits.

One really must consider the real life situation though. If you are taking on water that fast you need a 240v pump then it really is time to pi$$ off to the life raft. In that sort of situation are you going to prat about trying to start a genny? Nice idea in theory but as I said I dumped the 240v pump for smaller 12v and a couple of manual backups. If the water is deep enpough and coming in fast enough to need a 240v pump you batteries are probably under water anyway.

Personally I would go for smaller 12v pumps which can be sequenced ie 1, 2 or 3 on at a time.
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Anonymous

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Re: 240 volt \'bilge pump\'

Sounds like an excellent idea to me if you can safely deploy a small generator at sea. I have an inboard diesel generator and will consider one myself - I am short-handed and our manual pump simply wouldn't be viable between my wife and myself. As for the safety - I can't see any problems but in any case you wouldn't be using it unless you wanted to pump around 300 litres per minute - which is a fair leak. The point of having it would be to allow you time to make some sort of emergency repair with bungs, blankets, etc. or wait for assistance (the lifeboats carry huge pumps).

All in all, it sounds like a good idea and could save having to take to the liferaft - and all that talk about a frightened man with a bucket is nonsense....men tire.
 

tcm

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Re: 240 volt \'bilge pump\' - better idea?

hi

I have had major leaks at sea involving deepish water and i must say that my immediate preference would not really be for a big dollop of 240V whilst evryone is soaking wet - cos they will all tear around for everything they can bag up or clear off the floor - as a biggish leak is one of those creeeping problems where it's worth "having a go" rather than a wham-liferaft problem such as waking to a fire.

I think the best thing is to use the engine - thus still giving you massive pumping power but not with 240v, and to this end the way to go imho is to have a valve arrangement such that you can divert the primary intake to suck from the bilge instead of the sea - a diesel engined bilge pump essentially with far more power than the genny which really, in a deepish bilge i wd want to turn off, not on.
 

fishermantwo

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Re: 240 volt \'bilge pump\' - better idea?

I have several 240 and 315 volt pumps to pump bilge water out of my fishing vessel. 240 volts is perfectly safe for the boat left on in the marina, its the low voltage like 12 volts that causes the problems. The problem you may have is finding a pump that will start with only 750 watts. Some electric motors have a very heavy draw at start up, especially single phase, you will have to check the specs very carefully. The advantage of using any 240 equiptment is the vast array of equiptment available, your not tied to yacht stuff.
Submersible pumps come with a variety of switch set ups or you may consider a dry set up with the pump mounted out of the way on the cabin floor with just a pipe and strum box in the bilge, separate float switch. Then you can select from a positive pump like a Jabsco or centrifugal, the choices are enormous.
 
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Re: 240 volt \'bilge pump\' - better idea?

[ QUOTE ]
I think the best thing is to use the engine - thus still giving you massive pumping power but not with 240v, and to this end the way to go imho is to have a valve arrangement such that you can divert the primary intake to suck from the bilge instead of the sea - a diesel engined bilge pump essentially with far more power than the genny which really, in a deepish bilge i wd want to turn off, not on.

[/ QUOTE ]I wouldn't want to use the engine cooling pump - having got the problem under control (which is the objective) you still want to be able to make harbour without assistance (which is also the objective). Besides, I can't imagine any raw-water cooling system using 300 litres per minute!

However, I agree that an engine-driven pump is a good idea but these are usually driven by a separate power take-off from the engine, say off of the main belt. To compete with a 750W electric pump you would need to have 1hp drive, so you would need to enhance the belt and take off pulleys - quite a major job. My father fitted this sort of arrangement to a Ford Thorneycroft 108hp but the pump went rusty and he threw it out after a few years. Whereas one could store the sort of stainless mains pump under discussion in a corner of a dry bilge, ready for use if required. There is no 240V safety issue. By the way, this pump could also be used as a fire pump. The cheaper of the two pumps on the website given is around £120, and they offer flat hose of the appropriate diameter. For well less than £150 you could be in business.

But this is probably of more interest to someone with a permanent 240V generator than a portable, I imagine.
 

pvb

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Flat hose...

If you've tried using the flat hose they sell for these pumps, you'll know that it basically only works in a straight line. As soon as you want to go round a bend, the hose kinks and dramatically reduces the flow. For use on a boat, you'd need regular bilge pump hose.
 

WhatHove

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Re: 240 volt \'bilge pump\' - better idea?

Thanks for this interesting and informed feedback - I think on balance I may go down the 240v route.

My genny is located high in the boat - at least half a metre above the batteries. But I take fishermantwo's point about the output - perhaps I need a bigger one. So how many watts do you need for an electric power-shower..? :)

(Incidentally, few 240V pumps are recommended for use with saltwater but a chap told me today that swimming pool pumps have to be chlorine proof, so are good for seawater too.)

The reason I worry about all this is that I once had a flooding experience halfway across St George's Channel which coincided with losing the engine driving the bilge pump thanks to a blocked diesel filter.

There were enough of us to sort out the filters, bucket out, and keep the vessel pointing into the weather on the remaining engine. Actually, it wasn't a particularly threatening experience as it turned out. However, if we'd been badly holed - and if we hadn't been able to restart the engine for some reason - it could have been a far more alarming experience. Then I might imagine welcoming tcm's cooling intake drawn from the bilge on the engine that was still running.

Cheers
WH
 

William_H

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Re: 240 volt \'bilge pump\' - better idea?

I have a garden 240v pump rated at 1000watts which is 20 metres down a 130mm diameter hole into fresh water but with calcium. It has been under water for 3 years and I expect it to stay there another 20 years. Needless to say it moves a lot of water running about 20 sprinklers easily. It does need to be kept under water and in fact has a bleed off of water from output over the body for cooling in case of low water level. The pump and motor are about 1metre long.
However the whole idea of a bilge pump so powerfull seems absurd unless you are going into the salvage business. In which case a portable engine driven centrifugal pump would be the go. Every farmer around here has one set up for firefighting so they are reasonably cheap.
I would spend my effort providing bouyancy tanks rather than massive bilge pumps. olewill
 

tcm

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Re: can\'t imagine

um, well agreed, our engines are 1200 hp each, so probably quite a lot more than 300l/min....

One really good reason for the bilge being flooded might be the blimmin genny hose knackered - in which case oh er bugger...

Has anyone really been soaky splooshy near-sinking here? It seems not! I was, ina midsice 40-50 footer and under NO circumstances wd i flick on the 240v unless i wanted to do myself in!
 

tcm

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\"no safety issue\"

eh? The 240 lines on a boat are routed above the waterline - which is now rising fast. in the middle of attempting to sort the fuel, or plug the hole - our fab bilge pump requires 240v, no? Why do you say there is no safety issue?

The very first move before going into engine room deep in water for me wd be - kill the 240v.
 
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Anonymous

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Re: \"no safety issue\"

[ QUOTE ]
The very first move before going into engine room deep in water for me wd be - kill the 240v.

[/ QUOTE ]What is the risk that you are so worried about? Fire? Shock? Can you explain? The old black and white movie scenario of dropping a heater into a bath to kill someone is an old wives' tale. It is highly unlikely that you would even get a shock, and if you did, it would be very minor unless you physically gripped the element. In any case, the boat wiring will be protected by an earth leakage breaker and it would be necessary to ensure a non-protected circuit for the 240V bilge pump - which would be perfectly safe; these pumps are designed to work underwater.

If the pump were to be run simply plugged into a portable generator with no earth bonding then there would be no problem since the supply would be floating anyway. As I said, electrical safety isn't an issue.
 
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Anonymous

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Re: can\'t imagine

[ QUOTE ]
um, well agreed, our engines are 1200 hp each, so probably quite a lot more than 300l/min....

[/ QUOTE ]Not many 30 foot sailing yachts have a pair of 1200 hp engines /forums/images/graemlins/laugh.gif
 

pvb

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Swimming pool pumps...

Did the chap who told you about swimming pool pumps also explain to you that they're not self-priming? It sometimes takes me two attempts to get mine primed after I've cleaned the strainer basket. Obviously, this makes them totally unsuitable for bilge pump use.
 
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