Bilge pump circuit breaker

My first 12 VDC panel project has bubbled up to the top of the list and now seems like the right time to also change the way my bilge pumps are powered. The boat was built with 12 VDC supplied to all three pumps via a breaker. Other than perhaps time on the hard (like when I took this picture), that breaker has never been off.

I need a new spot for a new breaker and that seems like the best candidate. My plan is to remove the 15 amp breaker and replace it with a new Blue Sea 30 amp breaker to power a new davit motor.

Question is, what is the best approach for powering the bilge pumps. My plan is to add a small "3 port" bus bar and wire that to the main DC bus, then move the three positive leads (one from each bilge pump) from the connection at the breaker to the new bus. The ground wires should be fine as is. What am I missing?

HeadedToTexas said:

What am I missing?

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Circuit protection.

L

When I started leaving my boat for the winter, I had others checking on it from time to time. I came back to find the panel breaker for the bilge pump in the off position, as one of those had the idea that all of my breakers should be in the off position to prevent any excessive power usage.
I have since installed a backup bilge pump that bypasses the breaker panel and will activate with its float switch so long as the batteries have charge.

You panel looks like it may be a Blue Seas panel. If so they sell a switch protector that stops a switch or breaker from being accidentally turned off. May be particularly important on a bilge pump circuit. On a previous boat my dog would brush by the panel and turn off the bilge pumps every time. Installed the protectors and it never happened again.

A-Series Circuit Breaker Toggle Guard

Lou_tribal said:

Circuit protection.

L

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Yes, you will need to add a sub panel with breaker(s) for the bilge pumps. Otherwise it should be fine. You don’t have any open breaker slots for the davit?

Yes, you need circuit protection. Fuses are still considered an appropriate form of circuit protection for bilge pumps. It is something no one can accidently turn off.

I've an always hot circuit that bypasses the battery switch that goes to a 100amp breaker, that goes to a 6 fuse panel where I tap off 3 25 amp fused runs to my bilge pumps. I've 3 Rule 3700 pumps
I guess we could talk about your 37ft boat with 3 bilge pumps where the combined draw is 15amps. That's not much pump.

Bilge pump wired directly to battery with a fuse. Use this blue seas product.
https://www.bluesea.com/products/5024/ST_Blade_Battery_Terminal_Mount_Fuse_Block_Kit
Simple, safe, and fool proof.

Agree with a 4 circuit Blue Sea fuse panel.
When I bought my old Phoenix 29, the PO pointed to two breakers on the power panel labeled “Bilge Pump“ and said “Never turn these off!” A few weeks later when we pulled the starboard engine, there was a rusty waterline halfway up the flywheel.

Circuit protection is what I was missing. Appropriate fuses provide circuit protection. That Blue Sea panel looks very close, though I need it to mount near and connect to my existing DC power bus rather directly to a battery.

Given that the bilge pumps are protected now and the Blue Sea Toggle Guard looks like an effective deterrent to well-intentioned "helpers," I may be better off leaving well enough alone and finding a different spot on my panel for the davit breaker.

That said, and except for the trim tabs breaker that I literally never use, yes, I am out of open spots. Seems like there are plenty that could be combined though. Why do the horn and radar need to be on separate breakers?

Asking why 2 different "devices" need to be on separate circuits/protection suggests you back up a bit and review some basic electrical theory before pressing on with your own electrical repairs.

Circuit protection is needed to protect individual circuit wiring except in a few situations such as lighting that can be daisy chained.

Certainly 2 critical items like horn and radar would be bad if you had to turn one breaker off and it killed both.

I vote for a separate bilge pump panel near a helm that is similar but has enough positions like this one.....

No doubt my understanding of basic electrical theory could improve, though in this case the root cause may rest with my appreciation of the importance of separate circuit protection for items like the horn and radar. Much like the daisy chained cabin lights, I get that turning off the breaker to service the radar would also disable the horn (in this example), but to me that seems like a very manageable problem and well down the list of problems one is likely to encounter while coastal cruising.

Perhaps my lack of respect for certain components is that I have yet to encounter their need in an urgent or emergency situation. Certainly could be the case.

Another possible "empty slot" that could be converted to the davit breaker is the trim tabs. Despite widely varying tank levels and other loading anomalies, I have yet to find the need to adjust the trim tabs. My surveyor was able to make them operate, but that is the last time they have moved. In my odd world, simple is best and I am tempted to remove the trim tabs and motor mechanism altogether. What am I missing there?

P.S. I appreciate the diplomatic handling of what is clearly a shortcoming in my understanding, psneeld. So often these days folks would assail someone for posting such a thing. Thank you.

First, if you need the radar, you may likely need the horn....and vice versa.

If the radar and horn are wired with 2 different sized wires, that's where the problem lies. Not for turning on and off, just wire short circuit protection.

Sure use the trim tab breaker if you shoot usethem anyhow. But a sub, fuse/CB panel feeding all the bilge pumps makes more sense as 1 panel reader for multiple pumps is a bad idea anyhow...unless it already feeds a sub panel.

Roger that. The sub panel also preserves future modifications as well as compensating for my lack of appreciation for separately protected power supplies to different components.

I have one that is battery direct that feeds bilge pump and propane alarm plus a couple others I can't think of now but important if necessary to shut off the main circuits.

Not mentioned (that I saw) is a buzzer/light indicating that a bilge pump is operating. My lowest and smallest bilge pump is float operated and connected with a buzzer/light. My boat's only regular water ingress is the shaft seal and maybe some rain water. When that pump goes off (less than every 10 days cruising) it always causes some momentary excitement. But it only last about 5-10 seconds, hardly longer than it takes me to verify what the buzzer is. If it lasted more than 10 seconds, then I have an issue and it's time to check the output, if any, of the other bilge pumps, one of which is hardwired and the other switch controlled. LED buzzer lights are a couple dollars. Placement is the usual problem. The buzzer pump switch also has a manual setting, so before I leave the dock I throw the manual switch, listen to the buzzer while the bilge empties, then go back to automatic knowing that I'm starting with a "dry" bilge.

Each bilge pump should be on it OWN circuit, separate wires including the negatives, separate fuses/circuit breakers, separate panel switches and float switches.

I agree also that if you get caught in poor visibility and are using the horn and radar you do NOT want a short in the horn circuit to shut down your radar.

Same for all emergency gear such as Nav lgts, VHFs, sounders, plotters, windshield wipers especially the one directly in front of the helm.

I am going to guess that a davit motor may need more power that many panels after several years can just have tagged on. Better may be a separate power run to the battery with a fuse right there. THen a H.D. relay which is energized from the panel switch. Then the final control is the UP/DOWN [direction control} relays operated by the up/down switches.

The breaker you have on the panel is to turn on the manually only as the bilge it’s self is connected directly to the battery via a fuse!

And now for the dissenting opinion. Your bilge pumps should not be on a circuit breaker, to use Jeff Cote's language, a bilge pump is an "unswitched" installation. The purpose is that your bilge pumps are always "on," that is ready to be activated if necessary.

Below is a short video (4 1/2) minutes on switched versus unswitched electrical hook ups on a boat. If you accidentally turn off your bilge pump circuit, it may not go well for the boat.

PS: Notice in the illustration Jeff provides, the DC panel is in the switched area.

In my opinion, bilge pumps should be able to be tuned on either automatically or manually.

Sure both can (maybe should be) be connected to the unswitched fuse panel and the manual source be switched

They also need a relatively easy way to be totally secured if necessary, say a bilge full of fuel or oil.

Only one source is a problem in an emergency and your auto switch is malfuntioning.

In my opinion, bilge pumps should be able to be tuned on either automatically or manually.

I am of the philosophy if it can go wrong, it will go wrong. If you have a switch to turn the bilge pump on and off, you have the potential to have the switch thrown to the off position by mistake, and it may not be you who does it, could be guys in the yard working on your boat who do it. By the way, when I bought my older boat, the bilge pump was only on a switch, I had to turn it on to work.

Not what I am saying, maybe poorly. Thpugh I thought the rest of the post sort of clarified.should have used the word both instead of either.

It should have 2, independent power sources. One through a float switch or equivalent and one through a breaker or fused switch.2 sources for redundancy/ convenience

Both probably should come from an always on buss.

I prefer to have each bilge pump fused and connected to a 3 way switch, for manual, off, and auto. (as psneeld suggests)

This is the switch I have mounted at the helm for each bilge pump.

https://www.theboatwarehouse.com.au...knHe1BAtBRWJ5u2kZtNGGXZmr0Fri-cBoC0b0QAvD_BwE


The advantages are:
-It has a green indicator light on when in auto. The red indicator light comes on whenever it runs, or when in manual. Easy to see at the helm.
-If the float switch fails (which often happens) they can easily be switched to manual if needed.
- Each circuit is individually protected.
- Easy to hook up an alarm for when a high level bilge pump runs.

psneeld said:

Asking why 2 different "devices" need to be on separate circuits/protection suggests you back up a bit and review some basic electrical theory before pressing on with your own electrical repairs.

Circuit protection is needed to protect individual circuit wiring except in a few situations such as lighting that can be daisy chained.

Certainly 2 critical items like horn and radar would be bad if you had to turn one breaker off and it killed both.

I vote for a separate bilge pump panel near a helm that is similar but has enough positions like this one.....

Click to expand...

Yep!

I would have separate breakers for each pump alone with a manual mode. If one pump draws too much, the others pumps will still work. As pictured above, I would use a separate panel that is powered off the batteries.

I think Mainship did it right and like my bilge pump set-up.
Each pump (4 normal and 1 high water) are powered through 2 breakers...

Manual oper one on the 12V breaker panel (inside saloon) but these are normally on and a reset button pops out if tripped so no easy way to shut them off here. These are powered (I believe) through the battery sw.

The auto side of the pump (through float sw) is powered thru a different panel/breaker that are push on but takes a small tool to turn the breaker off. These are always powered and bypass the battery sw and are located in a separate locker on the aft deck (includes items such as CO detector, etc that are normally on)

High water pump is alarmed and activates all other pumps if high water pump activates.
Manual Sw & Pilot lights at helm ID if any pumps are activated.

As RSN48 stated you need a switched and an unswitched buss. Bilge pumps, CO alarms, smoke detectors, etc. on the unswitched buss. You want this buss always on, no chance to turn it off accidentally. All others on the switched buss, which in your breaker panel. Not of the opinion that fused are used instead of breakers on the individual pumps. A lighted, tripped breaker lets you know immediately you have an issue to resolve.

It's important to note, every pump, every motor load for that matter, must be protected by its own fuse or circuit breaker, you can't have a master breaker for multiple pumps unless they have individual breakers or fuses as well. This is a peculiarity of motor loads in particular. While the primary purpose of over-current protection, fuses and circuit breakers, is to protect the wire, in the case of motors it is also used to prevent over heating in the event of a full locked rotor. More on this subject here https://stevedmarineconsulting.com/over-current-protection/

Bilge pumps can and should rely on circuit breakers rather than fuses, if for no other reason than troubleshooting a short could use up all your available spares. Bilge pump CB's most, however, always utilize protection covers to prevent them from being turned off inadvertently. Such covers are readily available from Blue Sea. Also, bilge pumps should be equipped with two position switches, auto-manual, and the manual should NOT be momentary or spring-loaded. If the float switch fails and you are flooding, you don't want to have to stand at the switch to keep the pump running. In the case of a bilge full of fuel or oil, you can turn the breaker off. More on bilge pump systems here https://stevedmarineconsulting.com/bilge-pump-systems-design-and-installation/

Automatic Reset Short Stop Circuit Breakers 12 Volt DC

I would hate for the boat to sink because the fuse or breaker protected it from catching fire.

Automatic resetting breakers lack ABYC compliance...

Steve DAntonio said:

Automatic resetting breakers lack ABYC compliance...

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I have also read of a motorhome owner that burned up his TOAD (dingy) due to an auto reset breaker in his line that charges / maintains his battery. I prefer the manual reset variety above auto or fuses.