Bilge Pump Switch

[Oliver Fleming]

Hi,
I am sure this has been covered before but I cannot find it
on google.

However I am sick of replacing bilge pump switches. ( I have a
shed full of floats!)

I thought to seal a mercury switch and put it on the float when
the float goes up the pump comes on (through a good relay)

However the switch comes on the pump runs for a very short time
and just clicks on and off driving the relay crazy.
I need to have a delay that will keep the relay pulled in say
5 to 10 seconds before dropping out and resetting.
Anyone have an idea or circuit that will do this for me.
Thanks
Oliver Fleming

 

[Paul]

Hi,

I'm curious as to why your bilge pump switches are failing. Is there a
common repeating problem? Maybe something I could look out for in my own
boat?

I have heard that the same people that make the tank gauge (that seems to
get good reviews here) are also making an electronic bilge pump switch with
no moving parts. According to their website it's due to be released in Feb.
next year. Here is the link, scroll to the very bottom of the page.

http://www.snake-river.org/Products.asp?ID=3

That doesn't help you today though, sorry about that.

Paul.

 

[Vito]

I need to have a delay that will keep the relay pulled in say
5 to 10 seconds before dropping out and resetting.

We used a big capacitor across high resistance relay windings. The
operate voltage also charged the capacitor which discharged thru the
winding when the operate voltage was removed keeping the relay operated
for a short time, but not for 10 seconds. We had special slow release
relays for that.

It might be simpler to fix the leaks (c:

 

[Derek.Moody]

Hi,
I am sure this has been covered before but I cannot find it
on google.

However I am sick of replacing bilge pump switches. ( I have a
shed full of floats!)

I thought to seal a mercury switch and put it on the float when
the float goes up the pump comes on (through a good relay)

However the switch comes on the pump runs for a very short time
and just clicks on and off driving the relay crazy.
I need to have a delay that will keep the relay pulled in say
5 to 10 seconds before dropping out and resetting.
Anyone have an idea or circuit that will do this for me.

You could use a simple RC delay to hold the relay circuit if you must but
what you really want is some built in hysteresis at the switch.

To take your mercury switch - add another one at (say) 15 deg offset, use
one to switch on and the other to switch off.

The comersial float switches seem OK in calm water - are you moored in an
exposed situation? I can't think of any other reason for repeated failure.
One other option is an air-pressure switch at the top of a tube open to
the bottom of the bilge.

Cheerio,

--

 

[Phil]

I have a "See Water" switch that I bought from Boat US for $29 and it seems
to work good. It has a little probe that senses water (no moving parts) and
turns the pump on and runs for an additional 8 seconds. I have it mounted up
from the bottom in the sump so it stays dry and when the water touches it
the 8 extra seconds of run time brings the water to the bottom of the sump.
Keeps the bilge completely empty.
Phil

 

[Gary Warner]

I've got two Rule 1100s that have the float/switch built into them. The
boat is not done yet - anyone have experience with these? Do they
hold up well, or no?

Gary

 

[Peggie Hall]

Seems to me that more frequent cleaning of the bilge to remove the glop
that cause a float switch to stick and burn out would extend their lives
considerably.

Just a thought...'cuz I cleaned my 2-3 times a year and never had a
float switch fail.

Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://shop.sailboatowners.com/detail.tpl?fno=400&group=327

http://www.seaworthy.com/html/get_rid_of_boat_odors.html

 

[Paul]

I'm not sure I understand what would cause a switch to fail, but I wouldn't
mind hearing about it in case there is something I can look out for.

In the meantime, the company that makes the tank gauges that everyone seems
to like are also working on a float switch with no moving parts. Due to be
released in Feb. 2004 I think it looks interesting.

http://www.snake-river.org/Products.asp?ID=3

(scroll to the very bottom of the page, it's the last entry)

 

[Matti K.]

alternative could be:

http://www.penguineng.com/wwitch/wwitch.htm

 

[Horace Brownbag]

My experience with Rule standard float switches has been a failure of the
wire or wire entery into the float it's self.

Exactly.

I've taken apart a few of these buggers and sometimes the float itself
leaks, and the internals have shorted.

I think they need to improve the quality of both the seams, and the
insulation.

 

[Dazed and Confuzed]

Hi,
I am sure this has been covered before but I cannot find it
on google.

However I am sick of replacing bilge pump switches. ( I have a
shed full of floats!)

I thought to seal a mercury switch and put it on the float when
the float goes up the pump comes on (through a good relay)

However the switch comes on the pump runs for a very short time
and just clicks on and off driving the relay crazy.
I need to have a delay that will keep the relay pulled in say
5 to 10 seconds before dropping out and resetting.
Anyone have an idea or circuit that will do this for me.
Thanks
Oliver Fleming

go to Radio Shack and get the "555 timer cookbook" you can make a delay
of as many seconds as you wish. it's cheap and easy.



--


Life lesson #48:

You can continue to puke long after you think you should be done......

 

[dboyd]

Folks:

After scanning so many treatments on the float switch issue, I think I didn't see any that
mentioned my setup. If I did, please disregard and accept my apology. I bought a
small bilge pump at West Marine, I think. I honestly cannot remember even the brand
name for sure, yet believe it actually is a WM model. It has no float switch--but an
electronic timer that cycles it on every two minutes, and some sensor that knows by the
load change if the vanes are being resisted by water. I hear the damned thing cycle for
about a second every two minutes, and shut off immediately if it encounters no
water...it's not loud or even obstrusive but I find myself already trained to notice it....

It's been there a year, hasn't failed yet, and regularly pumps the bilge sump dry after a
shower or bilge rinse.

I'll verify the make/model asap and report it here soonest

Cheers-

Boyd
32 ft Motorsailor, Baltimore


alternative could be:

 

[David Flew]

C'mon Lew, float switches are not that bad. Compare then with pressure
switches - last I saw THEY had a MTBF of 12 months. You must admit that the
cast bronze type float switches with magnets actuating mercury switches in a
separate sealed bronze housing last a little while .... But I'd rather
spend the money on a pressure transmitter and use software to turn things on
and off.

But this does nothing for our problems with bilges in wooden boats, where we
have to contend with salt water, pitch roll and waves, and expect absolute
reliability. You would think the bilge pump would be the item to fail, and
the switch the easy part!
The last switch failure I had actually caused the leak - insulation failure
on the hot wire, electrolysis and lost the copper nails in what I think is
called the keelson cover strip. Under the engine where it's easy to find of
course.
I'd assume the majority of Rule's sales are to trailer boaters where switch
failure is irrelevant. So where to from here? Do we throw out a challenge
to the rec boats electronics guys to come up with a solid state solution, or
do we just put up with the problem?

As a suggestion, we need something which is 12V DC powered, minimal current
draw, uses conductivity between well spaced electrodes, AC to the electrodes
to prevent corrosion, time delay on and off, totally impervious to water,
protected from short circuit, reverse polarity, excess load, can be home
built, cheap ...
I can dream about the specs, I could build it from a kit, but I would not
have a clue where to start for a design.

Or we can just keep on putting up with the crap in the boat shops.

DF

Sorry about the cross-post, but I can't figure out how to turn it off.
DF

 

[Brian Runyard]

Mine have failed, nothing to do with muck in the bilge, have failed
internally

Seems to me that more frequent cleaning of the bilge to remove the glop

Mine have failed, nothing to do with muck in the bilge, have failed
internally

that cause a float switch to stick and burn out would extend their lives

considerably.

Float switch sticking might cause the pump to burn out not the switch.

 

[Vito]

Of course before that, everyone had a manual bilge pump and we never worried
about bad switches. Oh! that's right, everyone still has a manual bilge
pump, just in case the Rule burns out. Hmmmm!

Lacking experience I rely on what the surveyor said while inspecting my
boat. "If water begins to flood onto your boat you'll drown. The manual
pump allows you to die of a heart attack instead."

 

[Paul]

happens. The AC and all the sinks dump into the bilge on this boat so

everything goes through the bilge. It's great for ocean cruising but
I'm sure it's hard on bilge pump systems.

Is this a normal/common setup, dumping sinks into the bilge? It sure sounds
pretty gross, why not just dump overboard through the hull?

3600 planes with transponders are burning 8-10 million
gallons of kerosene per hour over the USA. R-12 car air
conditioners are responsible for the ozone hole, right?

I don't get the point about the transponders.

 

[Paul]

That's a keeper.

 

[Paul]

Hmm, I guess I never really thought of it. But I think of stuff like in the
morning draining a half-empty beer can or coke can or the remnants of cold
coffee from the pot. Just seems ... I don't know, weird to think it's going
into the bilge. Of course you chase it with water so I suppose it could
actually keep the bilge cleaner.

What kind of boat is it? Do you have pics online somewhere I can peek at?

You never answered my question about the transponder.

 

[Keith]

What if a fuel tank ruptured, filling your bilge with diesel. Or a major
fuel leak. You don't want to be pumping that out into the water, do you?
Yea, there's a need to have an "off" position, or at least a breaker where
you can turn them off.

 

[Rick]

It doesn't stink at all because it flushes
right into the big pump.

God it stunk ... P-U!

3600 planes with transponders are burning 8-10 million
gallons of kerosene per hour over the USA. R-12 car air
conditioners are responsible for the ozone hole, right?

I don't get the point about the transponders.

You never answered my question about the transponder.

Don't hold your breath waiting for one ...

Most turbine powered aircraft are fitted with transponders so that is
like saying running lights or control surfaces are part of the problem.

Larry, look up transponder, R-12, kerosene, then look up
"non sequitur."

And then add another layer of tinfoil to your helmet.

Rick