# Lift Station



## knowledge29 (Nov 6, 2010)

Hi guys, I have a problem and seeking some advice. I have a lift station with two grinder pumps with float switches. 1. for high alarm 2.to prevent nuisance starts 3./4 to each grinder pump. It all goes back to a controller with a breaker two H.O.A. switches to each motor. Problem im encountering is..when both motors are on auto for some reason its tripping out the breaker. When I leave one motor on off and the other on auto it works fine. The feed to this controller is a ten gauge wire 120v distance is about 400ft thats a ball park estimate. Im thinking the problem lies in which when the float switch makes on one motor and the other the motor cycles off, during this transition it is pulling more current then there is available and trips out the breaker..What you guys think?...thanks for your help..Oh and its all controlled from a cube relay


----------



## backstay (Feb 3, 2011)

You should have a relay that alternates which pump will start first. Then the second pump won't start until a hi level float is tripped. You might have a stuck/or bad start float and the station is cycling on the hi level. But you would get an alarm every time the pumps ran.


----------



## BBQ (Nov 16, 2010)

Not much to go on but with most of these it works like this 

From the lowest float working up.

Bottom float, pumps off

Second float up one pump run

Third float up both pumps run

Forth float up alarm for high level

Usally there is an alternating relay to swap which pump runs first to keep the time in both pumps equal

My best guess is you have ground fault with enough resistance that it will only trip with both pumps on..

But you need to know the pump current ratings and take some readings.


----------



## user4818 (Jan 15, 2009)

The problem is with the poo. :jester:


----------



## backstay (Feb 3, 2011)

What /\ said.


----------



## BBQ (Nov 16, 2010)

Peter D said:


> The problem is with the poo. :jester:


As it always has been and will always be until the earth is sucked into a black hole.


----------



## Jlarson (Jun 28, 2009)

Did you check amp draw? Pull the pumps to see if they are ragged up?


----------



## BBQ (Nov 16, 2010)

Jlarson said:


> Pull the pumps to see if they are ragged up?


Hell no, they are dirty.


----------



## Jlarson (Jun 28, 2009)

That's why I have fire hydrant adapters and a penta wrench :laughing:


----------



## user4818 (Jan 15, 2009)

Jlarson said:


> That's why I have fire hydrant adapters and a penta wrench :laughing:



Yeah well we know what you're about: roofing, going into the sump pit, cleaning up a burned up buss bar...no surprises here. :no:


----------



## Jlarson (Jun 28, 2009)

Peter D said:


> Yeah well we know what you're about: roofing, going into the sump pit, cleaning up a burned up buss bar...no surprises here. :no:


I have too many tools and too much random knowledge to stick to one trade. :laughing:


----------



## BBQ (Nov 16, 2010)

Jlarson said:


> I have too many tools and too much random knowledge to stick to one trade. :laughing:


But can you change a bumper car clutch or know the correct max RPM of a Scrambler? :laughing:


----------



## Jlarson (Jun 28, 2009)

BBQ said:


> But can you change a bumper car clutch


If you could I can :laughing:



BBQ said:


> or know the correct max RPM of a Scrambler?


No faster or slower then necessary. :laughing:


----------



## BBQ (Nov 16, 2010)

Jlarson said:


> If you could I can :laughing:


I said can, not could. :laughing:


Bu yeah I am sure you could.





> No faster or slower then necessary. :laughing:


Sorry incomplete answer.

No faster or slower then necessary .. to cause a wardrobe malfunction.


----------



## Jlarson (Jun 28, 2009)

:laughing:


----------



## brian john (Mar 11, 2007)

Use a amp clamp with min/max and a DMM with min/max and capture inrush and voltage drop with one pump, try with two pumps.

Verify instantaneous trip of CB (maximum current per the curve)
Megger every thing.
Change to different CB if necessary.


----------

