10 guage to 16 guage?

[SailingFree44]

Good evening folks,

So the 79 bilge finally went out and I am almost done installing the marine raider automatic bilge pump. My first bilge pump replacement and it’s been FUN to say the very least.

Pretty lost right now though, due to inexperience in the electrical field.

the Boat wires, that are meant to connect to the bilge pump are

the red hot wire: 10 guage
The black ground: 12 gauge
The pump wires: 16 guage

How do I splice this wires properly for the best results? I have most things to get the job done, except a solder, if it will be needed, I’ll look into it.

 

[Ralph Johnstone]

Can you supply the name and model of the pump ? Sounds like one of these rich and effluent pumps with the level controller built into the pump. With that info it's easy to pick up a wiring diagram from the net.

From there it's easy with no solder needed, only crimp connectors.

 

[Rich Stidger]

Normally when joining two wires a butt crimp connector is used. These connectors are commonly sized for one or two close sizes of wire- like 14-14, 12-12, 16-16, 14-16. However when the wire sizes are very different, these butt connectors don't work well. If the larger wire fits, then the smaller wire is way too loose to be crimped properly.

One solution is to use a connector where both wires are inserted in a single hole and then crimped. Since both wires are crimped together, the connection is secure.


For your bilge pump, be sure to seal the connector with a liquid rubber sealant or caulk so to prevent water intrusion that will eventually ruin the connection.

 

[mermike]

View attachment 206846

View attachment 206847

While Rich is correct that you are looking for crimp connectors, neither of the types shown will give you good long term service. You're looking for heat shrink connectors of tinned copper (from Ancor or FTZ) that will seal out moisture. This is especially important in a bilge pump installation, and critically so if the connections might be submerged.

 

[dlochner]

If you use quick disconnect fittings the wire size will not matter, use the appropriate size for the wire, the connection is standard ¼".

Or use a step down butt connector, one side will be 10-12 ga the other 16-16 ga.

 

[SailingFree44]

Thank you all!!

The pump name:
Marine Raider 800 Gph Automatic Bilge Pump.

Cool, that sounds like a plan, both wires with the see through single connector then marine sealant, and maybe it’s over kill, shrink wrap on top it all, to seal the deal perhaps?

And out of curiosity, the difference of 10 to 16 does it matter? Could that overload the pump or breaker? Trying to understand the electrical side a bit more, it is interesting, just complex.

My switch is just a two way. I bypassed the brown manual wire, leaving only the red n black.

 

[Davidasailor26]

16 gauge can carry up to 10 amps, so that should be adequate for the pump. They probably provide the heavier gauge wire to minimize the voltage drop over the longer distance. Just be sure that the fuse or circuit breaker doesn’t exceed 10A.

 

[SailingFree44]

The prior owner did all types of electrical things I do not understand. I know that I have two circuit breakers rated at either 30-45 amps. And the fuse that was used in the prior bilge pump which is the same fuse still in there is a 30 amp fuse. What should I do?

 

[jviss]

I think it's odd that the red and black are different gauges.

16 seems small for the pump wires, but it's also the smallest gauge the ABYC allows, so it's O.K. I would consider an inline fuse to protect the pump and pump wires, and make sure the circuit breaker in the panel is sized to protect the red and black. But, I could be all wrong about that!

 

[dlochner]

Fuses and circuit breakers protect the wire, not the device. Think about it, the fuse will blow if there is an over current situation on the wire. Broadly speaking overcurrent when there is a short in the wire prior to the device or when there is a failure within the device. The fuse protects the wire after the short, not before the short occurs. The fuse should be sized to protect the smallest diameter wire on the circuit.

Sometimes a larger diameter wire will feed several devices, in these cases each individual device will need circuit protection (fuse) at the point at which it connects to the larger wire, typically a terminal block or fuse block.

 

[smokey73]

Since the PO did things you "don't understand" first thing is to make sure how the power gets to the bilge pump. In my boat, and most that I know of, the bilge pump is wired such that it is powered, even with the DC main off (ie directly from the battery with a fuse in line). It frequently has what looks like a "breaker" but is actually a switch that allows you to run the pump while you hold it in the run position and it spring returns so that the pump will come on when the sensor detects water in the bilge. Just my 2 cents.

 

[SailingFree44]

Lots of information, thank you.

The original Bilge pump ran like that. Wether the batteries switch is on all or not, the pump will run, any which way. I like that and I hope after I wire it, it remains like that.


I see, that would be the 16 gauge line I believe. Does that mean I use a 20 amp fuse?


I think it’s odd as well to have these different shaped wires.

That’s why I am being extra cautious. I don’t want to damage anything.

 

[dlochner]

Lots of information, thank you.

The original Bilge pump ran like that. Wether the batteries switch is on all or not, the pump will run, any which way. I like that and I hope after I wire it, it remains like that.


I see, that would be the 16 gauge line I believe. Does that mean I use a 20 amp fuse?

One of the basics in DC wiring is learning to read an ampacity table. These tables will tell you how much current a wire can safely carry. Some are associated with voltage drop calculators which tell you how much the voltage will drop given a length of wire. Remember in 12v wiring the length of wire is the total length from battery to device and back to the battery.

Blue Sea Systems has a handy calculator that will do the calculations on wire size.

If you are going to dig into electrical systems on your boat consider purchasing a good book on boat electrics. Charlie Wing's Boatowners Illustrated Electrical Handbook (amazon link) is well regarded and easy to understand.

Nigel Calder in partnership with a couple of other authorities offers a course on Electrical Systems on boats.

https://boathowto.com

 

[jviss]

Fuses and circuit breakers protect the wire, not the device.

I'm not sure, Dave, we are in agreement or not. I think perhaps not, on a small point. Circuit breakers typically protect the wiring from the CB to the load. If you load has smaller wires, a fuse at the feed to the load will protect the smaller wires and load. So, you can have both a CB and fuse in the same circuit.

See this excellent article:
Fuses & Circuit Breakers: Overcurrent Protection (OCP) on Boats - Nigel Calder

 

[jviss]

By the way, bilge pumps are often (usually) a special case, in that they are often wired directly form the battery, bypassing the electrical panel. The bilge pump circuit should then have a fuse (usually an in-line fuse holder) right at the battery that is sized for the smallest wire in the circuit, usually the wires on the pump.

The only downside to this is that the pump can flatten and damage the batteries!

I currently have a pump issue where it's not pumping even though it's running, and if I leave the. switch in "auto" it will run forever and kill the batts. It's my intention to install a low voltage disconnect to protect the batteries.

 

[dlochner]

I'm not sure, Dave, we are in agreement or not. I think perhaps not, on a small point. Circuit breakers typically protect the wiring from the CB to the load. If you load has smaller wires, a fuse at the feed to the load will protect the smaller wires and load. So, you can have both a CB and fuse in the same circuit.

See this excellent article:
Fuses & Circuit Breakers: Overcurrent Protection (OCP) on Boats - Nigel Calder

Really, did you read the whole post? Let me quote:

Fuses and circuit breakers protect the wire, not the device. Think about it, the fuse will blow if there is an over current situation on the wire. Broadly speaking overcurrent when there is a short in the wire prior to the device or when there is a failure within the device. The fuse protects the wire after the short, not before the short occurs. The fuse should be sized to protect the smallest diameter wire on the circuit.

Sometimes a larger diameter wire will feed several devices, in these cases each individual device will need circuit protection (fuse) at the point at which it connects to the larger wire, typically a terminal block or fuse block.

Emphasis added.

 

[jviss]

Really, did you read the whole post? Let me quote:



Emphasis added.

Ah, gotcha. Thanks!

 

[jssailem]

Lots of information. Yes. While the basics of DC are not complex, the rules are pretty exacting. The reason? Get it wrong, seriously wrong and you can start a fire.

One of the rules about DC power: What flows out of the Battery must flow back to the battery. You have a Red wire ( identified as 10 gauge) connecting to the positive side of the battery and a Black wire ( 12 gauge ). Black has been for years used on the negative side. More recently yellow is being used. You should use the same wire gauge for both connections to power the pump.

When you say 16 gauge are these the wires coming out of the pump?

How many feet is the pump from your power source?

 

[JamesG161]

As @Maine Sail points out, it is power at the pump that decides the Bilge Pump capacity.

The larger the wire diameter, the less the power loss.

Jim...

 

[SailingFree44]

Lots of information. Yes. While the basics of DC are not complex, the rules are pretty exacting. The reason? Get it wrong, seriously wrong and you can start a fire.

One of the rules about DC power: What flows out of the Battery must flow back to the battery. You have a Red wire ( identified as 10 gauge) connecting to the positive side of the battery and a Black wire ( 12 gauge ). Black has been for years used on the negative side. More recently yellow is being used. You should use the same wire gauge for both connections to power the pump.

When you say 16 gauge are these the wires coming out of the pump?

How many feet is the pump from your power source?

A rough estimate, 8-10 feet.

Yes, the pump comes with 16 gauge.