Bilge Pump Failures ?

[GordMay]

I'm researching an article on Bilge Pump Systems, and seek information/stories of Bilge Pump Failures - especially anything relating to FIRES caused by fouled/failed pumps.
I ask about fires, because I have never encountered an overload (severe enouigh to cause a fire) due to a locked-up pump. I want to confirm or correct my opinion that it's not a significant hazzard (with properly sized wire).
Other failure mode information could also be useful.
Thanks,
Gord

[AnchorageGuy]

Gord, Been boating all my life (a long time) and the pump itself has failed me maybe twice. But many, many, many, many times it is the float switch. Rule is the absolute worse. I wonder why no one has sued them because the boat was lost. I have NEVER found one to last more than a few months. Now I use anyone elses product but theirs. Not a fire situation, but twice they stuck open and virtually burned up the pumps. If not wired properly there could have been a bad problem. Don't know if this is what you are looking for. Chuck

[delmarrey]

What is making these switches fail? Cheap craftsmanship? The marine supplier likes to keep supplying. There are float switches out there that work like fuel tank switches (a donut float on a riser tube - reed switch) that are water tight and non-corrosive. They are not cheap, but how much is a boat worth? Or how about two float switchs. one an inch or two above the other as a back up in case the first one fails! as well as a periodic test to check ALL safety devices! That includes the proper fusing to avoid electrical shorts.
Just some suggestions ......................._/)

[tenknots]

I work for a marine insurance company and I can tell you that there have been fires started by bilge pumps. Locked rotor conditions can cause the pump to overheat and melt. In theory, this can be prevented, but only by placing the appropriate fuse within 7 inches (per ABYC) of the POWER SOURCE. If the wire is fused at the pump (common), the wire from the power source can overheat before the fuse blows. This is where locked rotor fires start usually.

Another source is low voltage. Due to inadequate wiring or bad connections, the voltage to the pump can decrease, which causes the resistance to increase. This seems like the most common fire hazard for bilge pumps. The ABYC did an experiment and lowered voltage on a common bilge pump. I don't remember how low it got, but the bilge pump began to melt before the 10 amp fuse blew.

Though there are cases of these pumps melting, in reality there are few actual fires. I can only recall one that destroyed a boat. Most fires were caused by the burning insulation on the wire and occaisonally something combustible (cheap bilge pump hose) would ignite.

I have personally had a Rule switch melt down in the bilge, though it didn't do any harm. The proper wire, fusing and connections would likely reduce the potential for damage to minimal.

[irwinsailor]

The guy I bought my boat from let the bildge pumps burn out and let the boat flood. One had a anti siphon valve totaly pluged and the back up pump was wired backwards he thing that is strange is that he seemed to know that he was having the problem and did nothing to fix it.

[GordMay]

A reversed polarity pump may still put out about 10% discharge, fooling the unwary into thinking it's "all right".
I ceased being amazed by foolish boaters & boatbuilders a long time ago.
Gord

[CSY Man]

Well, I have not really had big problems with bilge pumps, but when the single Rule 2000 got a bit long in the teeth and the hose started to get brittle, I ripped everything out and started with a clean sheet....

Installed a Rule 3700 GPH and a Rule 2000, both with separate wireing, separate panels and separate Ultra Junior swithces.
Also ran new hoses, the white "sanitary" hoses for heads, not the thin plastic stuff they advertise as "Bilge Pump" hoses.
Double hose clamps all over and only 316SS.
One hose got a check valve as well as a generous loop, the other one got the big loop plus an anti-siphoning vent.
Been experimenting a bit with them valves, but due to the angle of the hoses and such, only a certain type of valve works.

The switch for the big pumps is located a few inches over the other one, so that the primary pump is the 2000, and if it can't keep up, the big one kicks in.

Also installed a red warning light for each pump in the cockpit, so I can tell right away if something bad is going on.

Put 20 gallons of fresh water in the bilge every month so each pump get a good work out...

The whole thing cost me about $700.00 plus a lot of swearing and swettin. (It is tight in the bilge of a CSY 33, believe you me.)

Happy with the system.

Here is some good info on bilge pumps and where I lifted the ideas for the above system.;

http://www.yachtsurvey.com/