Bilge Pump wiring options

[O C Diver]

So I'm working hard on my trawler refit and am in the process or rewiring, plumbing, and upgrading my bilge pumps. The two pumps were originally set up on a seperate fuse panel that is always on (unlike the main breaker panel that can be switched off), and each pump is switched (in the pilothouse) with either "on" or "controlled by a float switch" (no off position). Liked the idea of a seperate panel for the four pumps I now have, but keep going back and forth on the switches not having an off position. Not having an off position clearly eliminates the possibility of them being accidentally turned off, a trip to the engine room to pull a fuse isn't a big deal and most likely will never happen anyway. But on all my other boats, there has always been an off position. What do you think?

Ted

 

[N4712]

So I'm working hard on my trawler refit and am in the process or rewiring, plumbing, and upgrading my bilge pumps. The two pumps were originally set up on a seperate fuse panel that is always on (unlike the main breaker panel that can be switched off), and each pump is switched (in the pilothouse) with either "on" or "controlled by a float switch" (no off position). Liked the idea of a seperate panel for the four pumps I now have, but keep going back and forth on the switches not having an off position. Not having an off position clearly eliminates the possibility of them being accidentally turned off, a trip to the engine room to pull a fuse isn't a big deal and most likely will never happen anyway. But on all my other boats, there has always been an off position. What do you think?

Ted

I wouldn't have an off position.

 

[Ski in NC]

I fretted over that too when I wired my boat. I ended up including an off position. The thinking at the time was if I had a diesel spill into the bilge I could stop the pumps. I use the push button breakers, four pumps in four compartments, two on house batt, two on starting batt, alternating fwd to aft. Hard wired to batts so batt switch position has no effect. On off auto, with a red led that lights when pump is on.

The pump panel is located away from the AC and DC panels, out of the traffic area, so anyone fiddling with those panels is not going to mess with the pumps. You can rack every breaker on the DC panel to off, pumps still active.

 

[alberto]

I would not have an off position.
You can use the braker instead of an OFF position for testing, etc.

Do you have beepers when the float switch activates? this is important.

I have also a cycle counter, to see if I am not in the boat for days, if something has been wrong in the bilge.

 

[BruceK]

I have one breaker, and individual switches for each of 2 pump/auto-switches, with On/Auto/Off. (Unlike the Lucas Dim/Flicker/Off options).
One day the breaker kept tripping due to a defect in one pump. Pending replacement, I could turn that pump off. The breaker no longer tripped and I still had an operative pump. Probably could have got there another way but with an "Off" position, it was literally "flick of a switch". Go with 3 position switches.

 

[LarryM]

I have one main pump and one larger emergency pump. They are connected to different batteries via inline fuses and Blue Sea 3-way bilge pump switches on a separate panel. I also connected a Sonalert horn to the emergency pump so that if it is engergized, I will know it immediately. So far, so good. Just the way I wanted it.

A couple of weeks ago I discovered that an OFF position can be a trap. While I was cleaning, I inadvertantly turned both switches OFF and didn't discover it for several days. They are Contura rocker switches and it is not that easy to tell the switch position.

Nothing bad happened, but I am now going to add green LEDs directly above each switch so I can determine at a glance when the pumps are armed in the 'AUTO' position. Live and learn.

Now, my advice is to really think about whether or not you want an OFF position on your bilge pump switches. If you do, be sure to include "Check Bilge Pump Switches" on your check lists.

Larry
M/V Boomarang

 

[Edelweiss]

I fretted over that too when I wired my boat. I ended up including an off position. The thinking at the time was if I had a diesel spill into the bilge I could stop the pumps. I use the push button breakers, four pumps in four compartments, two on house batt, two on starting batt, alternating fwd to aft. Hard wired to batts so batt switch position has no effect. On off auto, with a red led that lights when pump is on.

The pump panel is located away from the AC and DC panels, out of the traffic area, so anyone fiddling with those panels is not going to mess with the pumps. You can rack every breaker on the DC panel to off, pumps still active.

This is the way to do it. Completely separate from the main DC panel and battery switch with multiple pump redundancy. I went a step further and added an LED to each pump switch to show when the switch is in the "Auto" position, as another poster mentioned. A little paranoid overkill maybe, but better safe than sorry!!

 

[tpbrady]

I have a small fuse panel near the helm that is directly connected to the battery. That is for things that always need power like the bilge float switches, memory in fuel flow meter, and bilge alarm. Each bilge float switch is wired through a fuse position on that panel. The manual switch for each bilge pump is on its own breaker at the helm and all have indicator lights. To shut down the float switch, all I do is pull the fuse.

I also have two other fuse panels in the same area, one that is ignition switched and one that is house battery for electronics. I did this to eliminate any in line fuses buried in wiring bundles.

Tom

 

[Marin]

I would not want an electrical device on a boat that did not have its own on/off switch. Ski brings up an important consideration with his statement about contaminants in a bilge. Particularly today when boat owners are increasingly responsible, aka have to pay for, any damage their boats do to the environment.

But anything that can run away, get stuck on, short out, overheat, catch fire, etc. I want an easy and quick means of cutting the power to.

Our electric bilge pump has the manufacturer's off/auto/manual switch and indicator light. It is mounted on the helm consol but not on or even near the DC breaker panel. To ensure that the switch can't be inadvertently bumped from one position to another, I mounted a small, simple drawer pull over it. This lets us get a finger underneath to operate or test the pump while eliminating the risk of the dog or one of us bumping the switch out of its set position.

 

[HopCar]

The switch panels that Rule sells for use with their bilge pumps have Momentary On, Off, and Auto positions.


"Controls any pump equipped with an automatic float switch. Toggle has three positions (automatic, off, or manual) and has a "fail safe" spring return to "off" from the "manual" position. Panel is black stainless steel and has red indicator light and fuse holder."

 

[Marin]

The panel in Park's post is what we have.

 

[Larry M]

When we had the sailboat, 1 bilge and 2 pumps. We had the day to day standard, small pump wired/fused to batteries with a counter, buzzer and no on/off switch (you could turn off the buzzer). The second pump was a Rule 3700 GPH with an on/off switch only for emergencies. The system worked well for the boat.

Hobo has 2 bilges and 2 pumps and these switches (plus a portable 3700 GPH pump). Only once have I screwed up and shut a pump off via the switch(s). I do like the pump "on" light. More than once I have noticed the light on. It has never been critical but something that needed attention. Is one system better than the other?

 

[O C Diver]

Lots of good points. Have 2 bilges, and each bilge now has a rule 2000 with a float switch as a primary, and a Rule 3700 with float switch mounted 2" higher as a backup / emergency. All pumps have panel indicator lights for pump running. The two 3700s have loud buzzers also. Still vacillating on the off position switch.

Ted

 

[High Wire]

I went with one of these
Amazon.com : MARINE BOAT BILGE ALARM PUMP SWITCH ALUMINUM PLATE MANUAL AUTOMATIC : Sports & Outdoors

Actuating the high high level switch triggers the alarm and starts the pump even if the switch is accidently placed in off.
Both normal and high high level switch needs to be able to handle pump current.

 

[Jay N]

I have two 3700 GPM pumps in the engine room bilge. Each has separate circuit breakers (25A), Auto/Manual control switches, and wiring. Since the bilge is normally dry, an alarm sounds whenever either pump is drawing power (these alarms can be muted while dealing with a flooding situation). An additional high water sensor is connected to an alarm siren guaranteed to wake everyone in the bay or adjacent docks if in a marina.

One of the questions about this wiring scenario is the appropriateness of circuit breakers for these pumps. One magazine writer is on record saying that these pumps are safe enough without wiring protection, and that it is more important to keep them going in an emergency. ABYC E11 wants protection on all circuits.

So, while the circuit breakers can be used as on/off switches, they are always left on, except when removing the pumps from the bilge. Yes, you have to remember to turn them back on.

 

[O C Diver]

I have two 3700 GPM pumps in the engine room bilge. Each has separate circuit breakers (25A), Auto/Manual control switches, and wiring. Since the bilge is normally dry, an alarm sounds whenever either pump is drawing power (these alarms can be muted while dealing with a flooding situation). An additional high water sensor is connected to an alarm siren guaranteed to wake everyone in the bay or adjacent docks if in a marina.

One of the questions about this wiring scenario is the appropriateness of circuit breakers for these pumps. One magazine writer is on record saying that these pumps are safe enough without wiring protection, and that it is more important to keep them going in an emergency. ABYC E11 wants protection on all circuits.

So, while the circuit breakers can be used as on/off switches, they are always left on, except when removing the pumps from the bilge. Yes, you have to remember to turn them back on.

Had a fire start in my bilge from a faulty bilge pump and too big a fuse in the circuit. The correct size fuse is specified for a good reason. The circuit needs to go open quickly when a device is failing.

Ted

 

[FF]

The bilge pumps and bilge alarms will usually be hooked to an >always hot bus< .

Even with the rotary switch off the feed to the pumps will stay live , I prefer a control by a CB sized for the wire , a fuse near the pump..

I also would suggest the House batterys be the bilge pump power source.

Bigger , deep cycle and the start is still reserved for the engine , which if started can be cross fed to power the house.

The engine batt Might be OK hooked to a simple bilge alarm , as they draw little juice , tho if unheard for a couple of days would kill the start batt.

 

[Skinny]

I need to rewire my pump in the spring. I would probably use a beaker that has a pull feature in order to disable it or use a switch which requires a manual action in order to position in the OFF mode. A red LED above it may be a good indicator when its in the OFF position.

 

[FF]

> I would probably use a beaker that has a pull feature in order to disable it or use a switch which requires a manual action in order to position in the OFF mode.<

Fewer guests or children are liable to pull a breaker than mess with a switch.

I vote for the pull .

 

[Shoalwaters]

Bilge sumps

In all the discussion on bilge pumps and related issues, I don't recall seeing mention of bilge sumps. I am fortunate to have one built into the lowest part of my boat's bilge. It is such a good idea that I am surprised all boats don't have them.

IMHO many bilge pump problems are caused by the pump and its wiring being continuously submerged in water - especially oily water which tends to make the wiring insulation brittle. The sump allows me to use a Jabsco 36600 belt-driven pump mounted well clear of bilge-water level. The only component of the whole system that gets wet is the bottom half of an Ultra Pump switch that controls the pump.

Rule pumps #1 and #2 with their own float switches are located slightly above the top of the sump. These would (I hope) take care of a major inrush of water, but otherwise stay warm and dry. They do of course need to be tested every few months.

The blue pipes are part of the fresh-water flush system - nothing to do with the bilge pumps.

 

[On The Rocks]

I have a large 12v (Rule 3700) bilge pump that pulls about 15 amps. The other day I noticed it is wired using 14 AWG. The distance from the pump to the switch/battery is almost 20' so it seems like it should have 8 or even 6 AWG? However the largest three wire bilge cable I can find is 14? I suppose I can run three seperate wires, I'm just surprised that there isn't larger gauge bilge wire. Am I missing somethin? Is the 14 gauge ok?

 

[N4712]

#10 Should be fine, anything bigger is unnecessary over kill.

 

[psneeld]

6ga would be necessary if you wanted no more than 3% voltage drop...and the wires were in the engine room and bundled....per most wire sizing tables...but reality of what most would do is run 10 ga as it's easier to find and work with.

The companies that I have worked for would use 10 ga 3 wire..... bad practice because of the coloring can be mistaken for an AC circuit...but if in the white sheath and labeled well.....it has never been an issue.

 

[O C Diver]

The companies that I have worked for would use 10 ga 3 wire..... bad practice because of the coloring can be mistaken for an AC circuit...but if in the white sheath and labeled well.....it has never been an issue.

That's what I did. Felt it was more important to have the wires in a protective sheath when pulling them through the wiring tunnels, and just labeled them where you could see them.

Ted

 

[psneeld]

That's what I did. Felt it was more important to have the wires in a protective sheath when pulling them through the wiring tunnels, and just labeled them where you could see them.

Ted

Can always put colored heat shrink on the ends if you are only half a perfectionist...

After installing and using countless bilge pumps....if you don't use the bigger wire sizes, have more than a couple feet of run, any bends, corrugated hose,and run the bilge pump on less than 12.6 volts..... I pretty much subtract one half to one third the capacity of the pump for a more accurate number of gph.

Not a scientific answer...but based on the pump mabufacturer's warnings, experienced writer's cautions and my own experience...the final pumping numbers are far less than what the model description is.

 

[O C Diver]

Can always put colored heat shrink on the ends if you are only half a perfectionist...

After installing and using countless bilge pumps....if you don't use the bigger wire sizes, have more than a couple feet of run, any bends, corrugated hose,and run the bilge pump on less than 12.6 volts..... I pretty much subtract one half to one third the capacity of the pump for a more accurate number of gph.

Not a scientific answer...but based on the pump mabufacturer's warnings, experienced writer's cautions and my own experience...the final pumping numbers are far less than what the model description is.

Yes, that's part of the reason I doubled the number of pumps from 2 to 4, redundancy and more realistic expectations.

Ted

 

[psneeld]

OC...hope you know I didn't mean to direct that towards you but to the OP...

I try to not infer others are totally without the basics..unless they specifically ask if something is or isn't OK...

I know based on your running a commercial boat you have been through the pump /alarm drill more than once for the USCG...

 

[O C Diver]

OC...hope you know I didn't mean to direct that towards you but to the OP...

I try to not infer others are totally without the basics..unless they specifically ask if something is or isn't OK...

I know based on your running a commercial boat you have been through the pump /alarm drill more than once for the USCG...

No worries, we're good.

Ted