Float switch is the wrong switch

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gnuorder

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I acquired a junk sump pump that had no marking, no float and seized bearings. I replaced the bearings and the motor runs well but before I put it in action draining my pool, I wanted to rig up a float shut off. The switch is internal with a pivot that pushes a rod in to turn on the motor and when the float drops, the rod pulls back to turn off the motor. When I first took it apart, they had bypassed the switch and I wondered why because it seemed to work. Now putting it together I find the switch itself is momentary but it has a housing and when the rod pushes in, it doesn't turn on until it's released. The next time it pushes in and released it turns off the motor. It makes it an on-off switch rather than a momentary switch. There is no part number on the pump or the switch that I can see. It's a unimax housing over the switch so I assume it's a unimax switch as well. But it's a different housing that I need. It's a 12 volt pump so the after market float switches I've seen wont work. I'm going to bypass the switch for now so I can test it for leaks and how many amps it will draw. The motor is rated for 32amp but I'm sure running amps will be much lower. The switch is rated for 5 amps which it drew running dry. I'm sure under load it will draw more amps than that. But the switch housing looks made for the pump. I'll post pics tomorrow if I get some interest.
 
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gnuorder

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amazingly enough, I found the switch. A bargin at $119. I should sell mine. It is 15 amp, not 5 amp. It's the wrong switch but it fits perfectly in the housing of the pump so there must be another one that is simply momentary. It's about 4 clicks down this page:



 

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I tested it out and it draws 15 amps in shallow water. It had two leaks, one where one of the wires went in which I was able to tighten up and fix with a larger wrench. The other is the pivot point for the float. I'm not sure how that seals but I was worried about it because I can push it in and out a little. I assumed it's some kind of press fit. I took some pics.
 

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Jeff Handy

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Any external piggy back type switch will control your pump.
Just leave it rigged as it was.

A 120 volt pump float switch should still control 12 volts.

Post some pics of everything.
 

Jeff Handy

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Don’t get electrocuted!

Plug into a gfci outlet, or get a gfci adaptor or gfci extension cord.

A pump might run just fine with a deadly current leak.

Caulk any leaks with aquarium sealant pure silicone, after cleaning and drying the area.
Put on a second coat after a few days of curing.

FYI I have seen pedestal style sump pumps running during a big rain event, with the motor completely submerged in a basement flood.
 

gnuorder

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Don’t get electrocuted!

Plug into a gfci outlet, or get a gfci adaptor or gfci extension cord.

A pump might run just fine with a deadly current leak.

Caulk any leaks with aquarium sealant pure silicone, after cleaning and drying the area.
Put on a second coat after a few days of curing.

FYI I have seen pedestal style sump pumps running during a big rain event, with the motor completely submerged in a basement flood.
Well I pulled the pivot point and it had an o-ring. I found a new one around the same size and greased it with silicon grease and it still leaked. I'm going to try a little thicker o-ring. This kit I got has only two with the same inner diameter. One is thin like the old one, the other is too thick. I'll have to find a new kit with one in between. Or just seal it up with some sort of plug since I can't use the old switch. BTW, it's 12 volts so I'm not too worried about electrocution.
 

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gnuorder

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Any external piggy back type switch will control your pump.
Just leave it rigged as it was.

A 120 volt pump float switch should still control 12 volts.

Post some pics of everything.
That's what I'm thinking. Most that I saw interrupted the 120 volts but whether using my battery charger or the transformer for the pool light, which I'm hoping I can use, I can plug those into the piggyback switch.
 

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Update on the pump. Have a setback. I got the housing sealed with silicon but when I tested, the motor wouldn't turn and drew too many amps even running dry. I thought the shaft seal was somehow too tight as the impeller tightened up but long story short, even out of the housing the motor draws too many amps and sounds noisy. I took it apart and the top bearing seems ok. Didn't take a look at the bottom bearing because it seemed to turn ok and is a ***** to get out. I checked the brushes and they are fine. Put it back together and it still draws like 10 amps and has a noticeable whine it didn't have before. That is out of the housing so it's not anything with the housing.

As far as a piggyback float switch, none I've seen so far are going to work as the cords are only 8ft and my pool is 8.5 ft deep. I need like 20 ft to reach the outlet. I prefer one that has just a switch and the float so I can hook it up to the 12v coil of a relay. I also prefer a verticle float as I plan on placing the pump in a 5 gal bucket.
 

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Update, I got the whole pump set up and working without a float shut off. I think the leaks somehow messed up the top bearing as I ended up replacing it with the old top bearing with a little better results. I ordered a new top bearing but for now I figured this will have to work. I bought 2 35 amp bridge rectifiers, wanted to buy a 50 amp but these would be delivered quicker. Got it running and only drawing 21.5 amps under water so I thought this would do. Well after 30 minutes, the bridge rectifier blew. Luckily I had two so I could confirm that was the only problem other than the bearing. Used the down time to set up a second box to house everything because the space inside the transformer was limited.

I have a float switch on the way which I will have to modify to shut off the transformer but that isn't needed till I get the pool mostly empty. Also have a cheap sump pump on the way as a backup with a 26ft cord and built in float switch. I hooked the current pump to a pulley system so I can keep it out of the leaves and debris and when it gets low enough, I can use either pump in a 5 gallon bucket. I have a 50 amp rectifier on the way though I don't think the 35 amp rectifier should have blow so I have my doubts about the 50 amp one too. I'm running out of time before the raining season starts so I hope these parts come sooner than later and actually work. Here are some photos of the brief time it was working and the mock up of the second box that will house everything making it easier to hook up and fix.
 

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gnuorder

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I skipped a lot of photos because it was tedious to upload them one at a time and it looked like they would have the wrong rotation. Let me include one more of it running before it blew out.
 

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gnuorder

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I got my cheap Chinese pump early today which is surprising because I didn't expect it till mid next month. It came before my float valve and other parts I ordered a week before it. It works better than I expected which kills the joy of my project but is getting the job done which is more important. Wish I took a photo of it before I put it to use. I put the float outside a five gallon bucket so that the bucket doesn't float when the water gets low. The pump is that light. Still working on setting up the old pump.
 
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