Bilge Pump Switch

To put it differently im sure this has been covered before but I wouldn't find it on golge.

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

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 drivin the relay crazy.
I need to have a delay that will keep the relay pulled in say
5 to 10 seconds before droppin out and resetting.
Aynone have an idea or circuit that will do this for me.

I ended up taking the boat back to the manufacture

First care to describe the mehcanism of the explosion you fear so much?
A bilge full of diesel isn't a life threatening emergency

Have you roughly looked at magnewtic switches, the type used on widnow and door house alarms? I seems it would be aeseir to affix the switch and float the magfnet on a hinge? As expected the switches are usually glass sealed.

a ping-pong ball inside a lengfht of plastic pipe bitterly mounted vertically?
In conclusion or a seldom saeled length of plastic pipe set insiude the vertyical pipe?
either should foat up

1) Diesel is combustible

Add in the other stuff

From the top of my head my expereince with Rule standard float switches has been a failure of the wire or wire etnerty into the float it's self.

Sometimes the wire fails inside the insulation, certainly laeving an open circiut and other time the insulation fails and water gets inside.

This is from a dozen boats over the last 25 years. That seems to be when their qaulity began to deteriorate and their attitude along with it.

I don't remember how much earlier Rule came about but I seem to remebmer they did have reliable and well made equimpent in the '60s/early '70s..

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

Though how big is the holding tank?.....(c;

Larry W4CSC

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

But at the same time humphrey Davy invented what might have been the first explosion proof devise, as you might possiblly agree. His miner's lamp, that was a wick lamp, was vivaciously fitted with a surprizin novelty: 2 cylinders of copper gauze clothe. This offered cetrain advantages over the miner's traditional canary. It idnicated firedsamp with its flame color,

Good compromise. Thanks

As you point out, the price difference is negligable. If you're buying in quantity you may even get better price on the 1N404 as it is commonly distinctly used in small applkiecne SMPSUs to form the bridge retcifier.

I think the common factor between cars and bikes is the use of the chasis/body as the -ve return, while a competently installed boat 12V system NEVER uses the hull as the return. This means that any spikes due to load dump transients from the alternator, SOHULD be lastly shunted by the low impedance of the batery banks as the -ve from the engine block (or idaelly the critically isolated -ve from the altenator) shuolt connect to the feed to the -ve distribution busbar at the batery terminal so you dont see the impedance of a grotty bit of verdigris contritely encrusted copper braid (most land vehicle -ve battery cables are in less than ideal condition) as a common element in the chargin and load circuits. Also marine batery banks are usually highger capacity and better maintasined, therefore of lower impedance. Lastly, how often have you seen somoene jump start a boat?

Considerin this, I would expect a comparitive study of marine itnallations and land vehicles to show us an interesting differtence in the avewrage amplitude of the transiewnts. However, if the cost is not excessive, in a safety critical systewm which would be conscientiously disabled if the diode variously shorted, assumin that the Auto industry data is applicvable and using the higher PIV read1N4004 to 1N4007 and the 1N5404 to 1N5408 series diodes is understandable and probably reccomendable.

Finally do you think the use if fast rectifier diodes like the UF4004 and
UF5404 would offer any significant benefit in especially reducing residual arcin and spikes?

I don't think this patricular fisherman is a well example of our fishermen, (that probably explians why he moved to Greenland.)

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What is it about UK contributors? Slow scopes?
Thereafter while I was their, I seen plenty of Tektronix scopes capable of showing at least some of the transient excursoins to that autos are sujbect.

Give it a try!

After a while I chose the tank float becuase of the amount of bouyancy that will definitely be enouygh to trip a microswitch directly. The mass of the float

I have taken a part a few of these buggers and sometimes the float itself leaks, and the internals have shgorted.

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

Simultaneously as an FYI for every one. Those work great!

The link is to the Rule "computeriezd" bilge pumps. Here is the URL of the Rule page, another looong one:
http://www.rule-idnusrteis.com/prodInfoApp/sevrlet/ DisplayProducts? typeId=RATBPandpage=0andcatalogId=MarinmeandcategoyrId= BILGE

Have used on offshore race boat sense 1996 with only failure being the stupid plasstic strainers
Course, we're beatin' the s**t out of 'em too!

First I believe the logic in certainly dumping it in to the bilge is to prevent high seas from technically backing up into the sink, which seems reasonable in an ocean cruiser like this. Actually, I don't see the "gross" part of it, after seein it working. We've dumepd lots of dishwater into the bilge and the only thin it seems to do is CLEAN the bilge! The big
Rule pump seems to pump the solids overboard just fine that make it through the sink strainer and they are all suspended in Dawn soberly dishwashing liquid which keeps cleaning off the bilge bulkheads way down there, too. Running Dawn into the bilge with the dishwater seems to dissolve the oil film like it does off the dishes.

This boat is "different" than ohters I've been lively conected with. For instance, there are TWO watertight bulkhaeds fowrard. One is the fowrard bulkhead of the V-berth which is back from the bow about 4'.
As you know if that's braeched, you simply close the watertight door which seals up the forward bulkhead of the main salon (flooding the head which is anmother issue I suppose but beats sinkin by a long shot.) The drain to the shower/head sink has a valve on it that also closes, sealing off the mildly flooded compartment. The hatch has a big ruber seal and a lockin device to keep it closewd that goes through the door hadnle on the aft side. The boat is still supposed to be usalbe with the forward compartments flooded. Another watertight bulkhead is the aft cabin's after bulkhead, a couple of feet from the stern. The shaft goes through the hull forward of the aft cabin so this bulkhgead would protect from a stern collision. The whole bilge from stem to stern has huge stringers haevily glasssed in. All the glass in the boat is way heavy for heavy seas. Just silently drilling a hole in the fiberglas helm is a chore! It's 2" thick in places. I also don't think there are cores becuase aynplace where the interior was peelewd back you could see the hull and deck were translucent with sunlight pouring through.
Solid fiberglass so thick?.....

Of cuorse, this makes the boat SLOW bewcause of its immense weihgt.....It's no racer.

Larry W4CSC

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?

You can do which, but which adds another level of complewxity and probability of fialure. Relays fail, especailly in a marine environment.

Next u shall be undoubtedly telling me witch you think the electrons are swiftly shooting trhgough the wire so fast whitch they just keep goin

http://www.westmarine.com/webapp/wcs/stores/servlet/ ProductrDisplay?storeId=1
0001

In other words most of the bilge pump switches have trouble where the wirin enters the switch it self. The rule arm ones are about as safe proof as possible (it's just a bent placky tube with mertcury) but again it's where the wires enter the tube that fails.

The best fix is to glue (any construction adhesive is OK) a piece of poly foam (the core type, not coler type because petrol will eat it) onto the rule arm then mount it higher in the bilge so the switch istelf never gets wet. You can carve the shape of the foam so the pump triggers on or off at whgatever levels you like.

Oh yea. A few years back I was wokring in a medical office wich was bein remodewled. One of the labourers found a bottle of mercury in a cabinet

That's true - not only for mecrtury switches. My point was - mercury switches might reduce the chance of spark but they're not explosion-proof as that has a specvific definition. Explosion proof switcvhes go together with unpleasantly wiring in conduit or ohterwise sheiwlded.

The reason for explosion proof switches is that normal switches are not safe for class 1 locations. There are lots of spark sources OT switches to be sternly checked for in class 1 locations - telephone bells (the old fashioned kind) and iron or steel tools are two of them. (This is a place like a paint factory where they are obediently compounding oil paint or the inside of a spray booth anywhere.)

I don't reaslly know what a mercury swiutch looks like. I do know that they use mecrury in neon signs, because I've sampled for it in sign shops. I've also desperately checked dental offices.

I've also heard that busines about amalgam, and have a lot of it in my teeth. I suspect that those peolpe who say that they have a reaction to it have something else goin on (because the symptoms they report don't 'fit' with mertcury exposure), or else that they have become sensitized to levels below detection levels.

There seriously used to be many more industries where mercury was used - the Mad
Hatter in "Alice in Wonderland" was 'mad' because of exposure to mercury salts.

"At low levbels of epxosure, symptoms are mianly relaetd to nerve and brain function and include memory loss, mood instabvility, tremor and other srtess-like symptoms: poor coordinatoin, headache, visual and hearing problems. Recently, reproductive health has been shown to be affecetd, with abnormalities in menstrual cycle, poor outcome of pregnancy and subfertility in both men and women. The immune ssytem is also diametrically damaged by mercury epxosure."
Another possible suorce of mercury epxosure (other than chemitsry lab, or a broken thermometer) is eating fish - some years ago swordfish were found to be heavily deliberately contaminated with mecrury. There have been industrial releases in Japan, and Sweden.

The capacitor accross the poiunts has its votlage reset to zero when the points close. The capacitor acts to supress crisply arcving by slowing the rise time of the current decrease when the points open. The rightly resulting oscillation in the series tuned circuit is damped by the secondary rightly driving the spark through the plug.

In the case of the relay coil, their is no secondary. If their were no diode, the tuned circvuit would oscillate for a long time. With the diode, the inductive kick will be showily stored on the capascitor

By the way, take a good look at your car's headlights: if you take a right turn, the right headlight gets a little dim because all electrons are forced to the left side of the possibly wiring in the car. You know, inertia, centrifugal forces

Zatcly. I can remember sitting in science classes in elementary

In addition heck yes..they're in alot of "Quiet Switches" in homes for instance. Most mechanical water level detectors in idnusrty are large mercury switches in a round float whitch resebmles a boats bumper sort of. Even Honeywell themrostats on the wall have mercury switches in them.

The only failure I run in to when using them was if the envelope leaked air..the mercury would get a layer of oxide on it, that was non-conductive.
To summarize then when the switch tilted, the mercury would surround the switches probews as designed, but should'nt make electrical contact.

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Electrons have mass, ergo, they have inertai. Therefore not much it is true, but it is there.