Low water level pump shutdown

[yraveh]

I decided to invest in low water level pump shutdown/auto top off systems
.
See http://www.reefkeeping.com/issues/2002-03/jg/index.php

I found that 2 t items can replace the whole system:

The float switch ~ $11
The relay ~$ 24
(see http://www.madisonco.com/accessories/R1-relays.htm)

This price would be valid for a total purchase of $300 or more.

If anyone else is interested please let me know.

Thanks

 

[Rogger Castells]

home depot sells one that works great, all you have to do is invert the float

 

[yraveh]

Do you use it without a relay?

 

[Rogger Castells]

yes

 

[yraveh]

what amperage can this switch run? (I could not find it on the home depot web page)

 

[jdieck]

I would not apply 115V to the float as in the designs above.
12V systems are a lot safer.

 

[yraveh]

I am not so concerned about it as Madison is the manufacturer of both the relay and the float.

JDieck, maybe U can help me with another issue.

Jon Garner DIY article above includes a digram for ` Constructing a Low-water Pump Shutdown System`.

He explains that "The reason this design is more complex than the top-off is because we don't want the pump to be restarted from water that siphons back from the tank, as this would cause the pump to turn on and off. It could do this repeatedly for quite some time, causing damage to the pump. The reset circuit will prevent this from happening. To restart the pump, simply press the reset switch. "

The problem with his solution is that a power outage would shut off the system. The pump would not restart upon resumption of power unless the push button is pressed. That is a big risk. say U R away for a couple of days.

What do you think?

 

[jdieck]

To prevent that you will need to use a second float signaling the pump when it is OK to turn on again.