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View Full Version : Apex float switch best convention?


Wingman6
08/22/2012, 04:57 PM
I'm setting up my Apex and planning to have 5 float switches to start. I was wondering what the best fail safe is for each for the following conditions. I have read they tend to fail open so you want to count on that.

Sump Level - sets the level in my sump. Set such that when float drops, closes and pump goes on. open fail does nothing

Reservoir - tells if fresh water empty. when water too low float drops and switch goes open. fails open ATO wont go on.

Sump high - tells if ATO has put in too much water. Float at bottom normally closed such that open kills ATO. Fail open kills ATO

Sump low - protects pump if water gets too low. If float drops switch goes open and kills return pump. Fail open kills return pump.

Tank High - Tells if overflow is clogged and kills return pump. normally closed such taht float at bottom has switch closed. Open kills return pump. Fail open kills return pump.

Anyone think one of these should be different?

swearint
08/22/2012, 06:39 PM
It's not so much that they tend to fail one way or the other. Rather, the default state of the Apex switch is OPEN. So if a float were to become disconnected or the wires are severed, the switch goes OPEN.

Todd

RussM
08/22/2012, 07:24 PM
It's not so much that they tend to fail one way or the other. Rather, the default state of the Apex switch is OPEN. So if a float were to become disconnected or the wires are severed, the switch goes OPEN.+1

See this thread: http://www.reefcentral.com/forums/showthread.php?t=2178133

It might help in your planning.

Wingman6
08/22/2012, 07:36 PM
It's not so much that they tend to fail one way or the other. Rather, the default state of the Apex switch is OPEN. So if a float were to become disconnected or the wires are severed, the switch goes OPEN.

Todd

That makes sense. So that being said, if you were setting up a float for the tank high or sump dry, you'd likely want it to shut something off so you knew about it instead of going along thinking everything was ok until you needed it.

swearint
08/22/2012, 08:31 PM
Generally, though sometimes it's a choice between the lesser of two bad outcomes. In your original post, I agree with all but the Tank High scenario. For that case, I don't have a recommendation. I'd be concerned about shutting down the pump due to a false signal. I think this falls into that category I just mentioned above. Whatever you decide, be sure to include any important cases in your email/alarm outlets.

Todd