Bilge Pump Wiring

[Bertramp]

My 1970 - 45C is set up for 3 bilge pumps. There are switches for the pumps at the upper and lower stations. I am in process of having pumps replaced/rewired. How do most of you have your pumps set up ?
Does house power have to be in on position ?
Does switch at helm only control manual operatioon of pump and the remaider of time it is on automatic ?
thanks

 

[rwetherington]

the right way is to have power at the float switch so that the float switch can turn the pump on when it needs to and a manual monetry switch at the helms to turn them on when you want to. I have seen this done also as to put a switch close to the pump to use if you are cleaning out the bilge or just check to see if the pump really works. Just a nice little touch on the boat.

 

[Bertramp]

all of this through the regular breaker panel .... true ?

 

[REBrueckner]

I never want my bilge pumps able to be "accidentally" shut off when my main switches are. I like to feed different bilge pumps from different battery banks so that if one bank fails or one pumps runs down a bank another is available as backup.

I also like a separate, extra, set of bilge pump float switches just for alarm purposes: I have these set higher in the bilge than the pumps....so if my bilge alarm system goes off I know (a) either a pump or bilge pump switch has failed or (b)a pump has been overwhelmed. In either case water is higher than it has ever been. An alternative might be to have indicator lamps which ignite whenever a pump does.

I added the extra alarm float switches in each bilge compartment after about 55 gallons of diesel siphoned into my bilge overnight in Cape Cod ...a fatigued fuel supply line. It wasn't enough to trigger a bilge pump, fortunately,but I might have been unpleasantly surprised had I not smelled diesel fumes the next morning. I used a spare bilge pump to extract the fuel and resued about 1/2 or more.

On a fiberglass boat I worry most about a raw water engine leak when I am underway...say a raw water hose or hose clamp breaks and water galore is pumped into the bilge. DD pump a LOT of raw water. To cover this, I use in line raw water flow detector with an alarm. So I get an immediate feedback (alarm) if raw water is lost...So now I need mostly concern myself with an exhaust leak while underway...small chance by comparison and the bilge alarm system should cover that.

No need to run bilge pumps thru the OEM breaker panel....but that's fine. Several of mine run that way, several run thru a separate house/aux panel added. I like physical wire routing diversity and power supply diversity.

 

[Genesis]

Bilge pumps in ENGINE ROOM or FUEL TANK spaces MUST have a shutoff switch for override purposes.

If you don't have one you are asking to some day pump the contents of your fuel tank or crankcase overboard and get hit with a HUGE fine. There ARE times when you DO NOT want the pumps to come on.

Hatteras from the factory wired them so that they have "normal", "off" and "momentary on" positions at the helm. I like that. The risk is that you may leave them "off" when you shouldn't, but that SHOULD be part of your regular "instrument scan" while operating.

On my 45C Hatteras also had high-water bilge alarms in all three primary spaces (forward, engine room and lazarette) that were completely separate from the bilge pump wiring but tripped the general alarm and a warning light. A second pump wired into that circuit is not a bad idea at all; the idea is to have that switch high enough that it NEVER trips in normal operation of the bilge system and in addition doesn't get wet and/or fouled but if you get a high-volume leak you both get warned AND the secondary pump starts immediately.

 

[TedZ]

This is not a simple question and it is not possible, with the intellegence of a bilge pump or the switch to serve all of these masters.

First, the switches are On/Off/Auto. Momentary switches are those that must remain pressed or held against a spring load. We don't have any of those for bilge pumps or at least we should not have.

The pumps cannot tell if the liquid is fuel or water. You can't reasonably leave your pumps off on the chance the liquid might be fuel. You will be wrong 99.999% of the time and risk flooding.

Most folks feel that direct battery connections with an in-line fuse is the correct electrical supply. I would reccommend that also.

Detecting the presense of petro chemicals is not easy but it is done all of the time. For example.

http://www.etracetek.com/tracetek/c.../notes_to_engineer/1300mr_engineers_notes.pdf

Boats i come in contact with don't have these systems but they are not outrageous...at least when compared to a fuel oil spill cleanup.

Lots of on-line examples of how to wire On/Off/Auto switches. Don't need to do it here i wouldn't think.

Hope this helps.

Ted

 

[Genesis]

On my Hatt the "ON" was spring-loaded (momentary)

AUTO was the switch, OFF was disabled.

The point to OFF is that I could select it when FUELING or working in the engine room or lazarette on the fuel system. That's the high-risk period of time when you DO NOT want an auto pump to come on.

That plus alarms for high water and you've got a system that isn't quite damn-foolproof (you could leave the switch OFF) but if its at the helm and you're paying attention and checking those switches as part of your regular surveillance of the gauges (e.g. engine, radar, depth, etc) I think you get the benefits of all of the above.

That's how my 45C came from the factory, and I liked it.