Cutting off the return pump

[Guppies Onli]

I intend to add a sump below my stand to my 2ft tank. But as the main tank does not have any internal hole drilled for the overflow, I'll be using those overflow durso pipe and a return pump.

My main concern is when the overflow pipe break siphon due to trapped air bubbles in the long run, the return pump will keep pumping water in the last chamber until dry. This may overheat the pump.

So is the onli way is to monitor the water level in the last chamber of the sump where the return pump is, with a float switch.

May I know how to connect this float switch to cut off the return pump? Is a level controller needed in this case (which is very expensive $200+ right)? Or is juz a float switch connect to a relay; but how to?

Thanks for helping out.

Take a look at Mode A Example 1 stallation which suits your application.

here is the link: http://www.jbjlighting.com/sys_ato.html

Fyi, I am using this.

[Guppies Onli]

Thanks bro. I'm wondering if the JBJ ATO (max. pump current of 2amp) can be used for return pump like Ehiem 1250 or 1260 which is 28W and 65W respectively. Not so sure what is the current rating of both pumps as the spec. not shown and wonder if can use Power/Voltage formula hehe?

BTW, are you using this ATO for topping up or for the return pump to main tank?

Thanks once again.

Originally Posted by nim75sg

Take a look at Mode A Example 1 stallation which suits your application.

here is the link: http://www.jbjlighting.com/sys_ato.html

Fyi, I am using this.

I am using for topping up and it will stop my pump if the reservoir is below the setpoint determined by how low the floating sensor in the reservoir tank.

For your case, you will place this sensor in your main tank so that when it falls below this switch the pump will not be activated.

The other sensor switch, you place it in your return pump compartment in the sump.

I didn't use the ATO as what you're intending to use as I have a check valve to prevent back siphon in the even of a power failure.

My application is identical to Mode A Example 1 and I had done a simulation to verify whether the top-up pump still runs if there isn't any water in the reservoir tank.

[Guppies Onli]

Thanks Nim.

I'm not to worry about the application but the pump rating (current) that the ATO can handle. What pump are you using? Brand and rating (power).

As the spec. mention onli handle up to 2A, so this is my main worry for a return pump that I mentioned earlier.

Thanks.

Not to worry as the max current the Eheim 1260 can draw is 0.2955A and this is derived from the formula P = IV

where P = Power (Watt), I = Current (Amps) and V = Voltage

So with 65W, the current or I is 0.2955A if the mains voltage is 220V AC.

Fyi, multiplying the amps by the volts, tells us how much power or watts the appliance needs to work.

Hope this helps.