Different Wire Sizes In Bilge Pump Circuit

[delmarrey]

You can buy different amp switches. Just get one that's rated for your pump.

ie:
35 amp: Buy.com - Rule Rule-A-Matic Float Switch W/ Detachable Base

14 amp: Sears: Online department store featuring appliances, tools, fitness equipment and more

12 amp: Float Switch

20 amp: Super Switch, Rule Float Switch 37A - iboats

[mikefossl]

ABYC standard suggests that a 10% voltage drop is ok for a bilge pump. The Rule 2000 draws at most 12 amps. Using 14 gauge wire and a 10ft run from the battery and assuming 2 ft of 18 gauge wire on the float switch this adds up to .76 voltage drop which is less then 10% and thus meets the ABYC standard.

That being said, I was just suggesting that using a smaller gauge wire on the float switch compared to the wire on the pump may not be an issue because it is the total resistance that determines the voltage drop. Rule includes the 35A Rule-A-matic as an appropriate float switch for the 2000 pump which is the smallest switch available from Rule.

[four winds]

Made me look. My main switch is the same, with larger wires making the run to the pump than the wires attached to the main switch.

The float switch is integral to the base of both my pumps, I assume, as there is no separate switch visible in the bilge.

Several have said this is no problem. I agree, thinking that the wires on the factory switch are sized for the current used. And the wires for the run to the pump are sized for the current used in concert with the length of the run.

There really wouldn't be any resistance from heat buildup as all wires are sized for the current and run.

[cburger]

Thank you gentleman.

[sailorboy1]

as long as the fuse/breaker is sized to protect the smaller wire; what difference does it make other that sizing for the voltage drop?

[colemj]

The practical problem isn't the voltage drop or the fusing protection. The practical problem is that you find yourself in the bilge fussing with frickin' stepdown crimp connectors and other hoodoo trying to make it all fit together with some reasonable expectation that it is reliable and sufficient to save your neck when the horse's tail raise hits the wind machine.

Having just installed this crap, it pisses me off that the manufactures KNOW you aren't going to run 18 awg wire to your bilge from your panel, and they laugh at you enough to give you wires on their recommended float switch that require a step down conversion just to connect them to their own pumps, let alone the house wiring. Probably saves them $11.95 per year on reasonably sized wire across the entire line.

And Rule is absolutely the worse offender of the bunch. And worse performer. And worse reliable. And worse customer support. Truly the Xantrex of pumps.

And we have one in one of our bilges (forced purchase - only pump on the shelf). When it goes (should be any day now - it is close to one day over warranty), there will never be Rule crap on the boat again.

Mark

[cburger]

Originally Posted by colemj

The practical problem isn't the voltage drop or the fusing protection. The practical problem is that you find yourself in the bilge fussing with frickin' stepdown crimp connectors and other hoodoo trying to make it all fit together with some reasonable expectation that it is reliable and sufficient to save your neck when the horse's tail raise hits the wind machine.

Having just installed this crap, it pisses me off that the manufactures KNOW you aren't going to run 18 awg wire to your bilge from your panel, and they laugh at you enough to give you wires on their recommended float switch that require a step down conversion just to connect them to their own pumps, let alone the house wiring. Probably saves them $11.95 per year on reasonably sized wire across the entire line.

And Rule is absolutely the worse offender of the bunch. And worse performer. And worse reliable. And worse customer support. Truly the Xantrex of pumps.

And we have one in one of our bilges (forced purchase - only pump on the shelf). When it goes (should be any day now - it is close to one day over warranty), there will never be Rule crap on the boat again.

Mark

I have asked this question before as well. I am amazed that people bet their boats on these chinsee plastic pumps. Is there no manufacturer who makes high quality bronze or cast iron heavy duty pumps more suitable to the marine environment. Are the commercial operators using Rule pumps to protect their vessels???

[delmarrey]

Plastic pumps are fine and dandy for RB's, but the big Boats/ships use bronze b/c they are rebuildable and more efficient in relation to their size. As well as most likely being a continuous use pump.

It's not economical to rebuild small bronze pumps except the raw for the raw water pumps on motors, due to their repairability with minimal parts.

You can install rubber impeller pumps for the bilges connected to DC motors, but they are not cheap like the plastic ones.

Mine has not come on once since I installed it 10 years ago. But I do have to raise the float switch ever week to make sure everything still works. One time the fuse had picked up a little corrosion and impede the system.

[Strait Shooter]

I just removed a rule 500 pump that was toast and a rule o matic float switch that had been intermittently failing. The wires on the float were 18 gauge and the wires on the pump were 16 (I think).

I agree with the sentiment that bilge pumps are not given the priority they deserve. I wanted to change that.

I installed a Jabsco water puppy impeller type pump as a primary and a Johnson L4000 as my "oh crap" secondary. Both are using ultimate switches and the Johnson switch and pump sit a foot higher than the Jabsco suction end. The Johnson has a high water alarm ultimate switch that tells me if the secondary kicks on and the Jabsco isn't handling a situation by itself. I also installed another high water alarm 1 foot below the first electrical connection that can short out the power on the boat.

The Jabsco is for maintenance and can get the bilge to within a quarter of an inch of being dry. The Johnson and it's switch let me know I have a more serious issue going on and to start checking through hulls while heading for a sandy beach if at all possible. The second alarm is a "get a last call off on the radio, grab your ditch bag, and get into your survival suit.

I think it works pretty well and I might be a tad paranoid but damn it feels good having a better plan than relying on that crappola rule pump and crappy switch for even slightly dewatering my bilge.

Another added bonus is the ability to use the water puppy as a fluid transfer pump should I need one.

I'm also going to install a Lavac head with a manual pump that I can use as an emergency pump if I have to.


John

[Me-and-Boo]

Originally Posted by cburger

I understand this, that's whys I asked the origional question. So what do you do about the the other components that come from the manufacturer with much smaller wire sizes that will be part of the circuit? Do I have to make my own switches?

Simple way of looking at this issue. Say your supply wiring is 18 gauge and the prewired unit has 20 gauge hanging off of it. No problem, just crimp on the correct connector. If your supply is 18 gauge and there are 16 gauge wires hanging off the unit, perhaps you need to check the steady current draw and consider a new run to the unit. You never tight limit your insulation, and hopefully neither does the manufacturer of the unit.

Next is the total current draw of your units. If you have an 18 gauge run, but your total constant current draw on that run is at the high for your wire size and insulation you need to rewire or move units to a different supply. There is no problem with load distributing to different supply lines. As long as the power source can supply the load.

[Blue Stocking]

Bilge pumps and switches submerged under the very substance they are supposed to keep out of the boat, is like taping the emergency fuel filters to the masthead.

[delmarrey]

Originally Posted by Blue Stocking

Bilge pumps and switches submerged under the very substance they are supposed to keep out of the boat, is like taping the emergency fuel filters to the masthead.

Isn't that why they are called submersible? They have to be submersed in order to work. And they should only be submersed when they need to pump.

[MarkSF]

According to code, there shouldn't be any wires on a boat thinner than 16 gauge. So the Rule switch with 18 ga is unsuitable for use on any boat!

I looked at the WM catalogue, and the Rule-a-matic Plus switch is rated for 20A with 14 gauge wires. Time for one of those I think?

[mikefossl]

Originally Posted by MarkSF

According to code, there shouldn't be any wires on a boat thinner than 16 gauge.

Really? Reference please.

[delmarrey]

Originally Posted by MarkSF

According to code, there shouldn't be any wires on a boat thinner than 16 gauge. So the Rule switch with 18 ga is unsuitable for use on any boat!

I looked at the WM catalogue, and the Rule-a-matic Plus switch is rated for 20A with 14 gauge wires. Time for one of those I think?

Oh no! My NEMA is going to fail