Bilge pump/float switch wiring

[fiestaMojo]

I'm trying to understand how the bilge pump and float switch (H33C) were originally wired. Looking at the wiring diagram (from the manual) it seems there was no On-Off-Auto switch, but the float switch had an independent feed. My float switch needs to be replaced, and I was thinking of adding an On-Off-Auto switch, but with the present switch working the pump would only come on with the panel switch in the On position; the On-Off-Auto switch should allow pump operation no matter if the main panel is powered up or not.

 

[Steve Dion]

Try this! Courtesy of Don Casey.

You pump may have 3 wires rather than the one that goes from the pump to the switch with a tee, but you should be able to figure it out.

 

[Paul F]

I'll give this a try. All of our boats have likely been rewired by now, so while this will work it may not correspond to your boat. My bilge pump manual switch is the third switch from the bottom on the D.C. line of switches. This switch is wired to the pump and when turned on operates the bilge pump. A second power supply is wired though the automatic flip float switch in the bilge. When water fills the bilge this switch activates and turns on the bilge pump. To make this power always available you should wire it directly to the battery bank with an inline fuse. This then will protect your boat and activate the flip float switch and bilge pump whenever excess water is in the bilge. It is a very good practice to test the bilge flip float switch whenever you think about it

 

[Ed Schenck]

I believe it originally had two feeds, one from an On-Off on the panel and one directly from the batteries. At least that is how my '79 H37C was/is wired. The on-off is a breaker and there should be a fuse in the wire between the pump and the batteries.

Wiring diagram from H37C manual(simplified): http://hunter.sailboatowners.com/in...&cat_id=38&aid=6732&page=article&mn=37-cutter .

You might be looking at this: http://www.boatus.com/boattech/casey/14.htm . Without the "automatic" part of the switch the diagram changes. The fused wire goes to the float switch. Then 12 volts already at the panel goes to the On/Off switch.

 

[fiestaMojo]

Bilge pump/float swiitch

Paul & Ed thanks, I think you're both saying the same thing - which seems to be what the wiring diagram is showing (in an inadequate way). . . Ed I looked at the wiring diagrams you linked in your post - better than the one I have for the 33, are they from the original Hunter manual? Paul, the DC wiring diagram from the 33 section of the manual shows a shower sump (bilge) pump - did all 33s have this pump? As always, thanks for all the replies and help. . .

 

[Paul F]

Yes, the shower pump is separate and on another set of wires to a switch on the wall of the head and then to the pump. Mine is disconnected. I am storing batteries in the shower sump. I have however put an additional pump in the engine compartment with it's own float switch. I had the stern tube break and flood the compartment. A lot of water. As you likely know there is little drainage from the engine compartment to the bilge. I don't know if the second pump would have handled the water but I figure two pumps are better than one.

 

[billclay]

Actually, you do not need a three-way switch (ON-OFF-AUTO) to get the operation you want from this circuit...

I just installed a new SuperSub automatic bilge pump in our 1979 H27. It has three leads - a negative, a switched positive (for "forced-on" operation), and an unswitched positive (for automatic operation). Obviously not the same thing, but note how I connected it...

The switched positive lead went to the middle terminal (the switched one) on the bigle pump switch on the electrical panel. I connected the unswitched positive lead to the hot-positive terminal (for automatic operation) on the electrical panel switch so that the automatic circuit includes the bilge pump breaker. That required one of those female spade connectors with an extra male spade on the side (sorry - can't find a picture) in order to double up the connections on the hot-positive terminal of the bilge switch (meaning, one wire from the bilge pump and the other wire from the circuit breaker for the bilge pump get connected to that post on the circuit switch).

For your application, your float switch should go between the bilge pump's unswitched/auto-operation wire and the hot-positive side of the bilge pump circuit breaker or switch, and the switched wire should connect to the middle terminal of your bilge pump switch. You will get auto operation from the float switch, plus you can force the pump on via the panel switch if the float switch dies on you again.

Good luck!

 

[sail_4_me]

A hardwired bilge pump

...is the way my 37c came originally, but I'm changing that with my rewiring project.

When I leave the boat, the big red switch will be left on, along with 3 circuit breakers on the AC/DC panel - 100amp main, bilge pump( auto ) and fridge. When I turn off the big red switch, all power is off.

The 100amp came with the panel, after I know the full potential of my new setup I'll reduce that to something more reasonable, or maybe add bigger speakers.

I've changed those blade-disconnects to permanent butt-connectors (shrink-wrapped), because when I unwrapped the electrical tape holding them together, they pulled apart. 8^) and I doubt that they make replacing the bilge pump any easier.

Different philosophy I guess, but I'd never have a hardwired connection in my house with its own fuse, that went out years ago.