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[TerenceF]

Often I have tried to explain to people the sheer power of the Apex community as one of the strongest reasons for purchasing our product. Sometimes they get it, sometimes they do not. Recently an issue came up where I think we could show this power. A user had this issue and needed help. He agreed to let me have his issue posted here anonymously. Let's see what you've got Apex community!

Please give the most complete answers and help you can for this issue:

I have a few questions regarding float switches. Can you email me the code for the following:

I already have one float switch in my sump tied to a plug name ATO_3_4 operating as follows (turns a solenoid valve on and off at the RO unit).

------------------------------------------
Fallback OFF
Set OFF
If Switch1 is open then ON
Defer 002:00 then OFF
------------------------------------------
When the above switch closes, two minutes after closing it shuts the solenoid valve off connected to my RO device. Please let me know if you see any issues with the above code. It\'s been in operation for two months now. Also, would the above switch be considered NO or NC? I would say NO? (water rises in sump to close switch. How do I know what position it will default to if the switch fails? i.e. Closed or Open?

My plan is to add two more switches:

The second Switch (Switch2) is a high sump water alarm. Should this be NO or NC? This would 1) send an email to me 2) prevent Switch1 from turning on the RO Unit (and would also shut off the RO unit if it is already on.) and 3) it would also shut off the protein skimmer.

The third switch (Switch3) is a low sump water alarm. Should this be NO or NC? This siwtch will do three things 1) Send an email and 2) shut down the main pump. It would also make sure the RO unit is in the off position.

I also plan on adding a switch at the top of the tank (Switch4) in future. This switch would prevent over flows. If it trips then it would shut down the main pump. It would be great to tie this switch to switch Switch3 and have some logic to turn on teh RO unit as long as Switch4 has never been tripped.

[swearint]

I always recommend that users program for the safest result in case of a failure. The most likely (or at least the most predictable) failure for a float is that it is disconnected. In that case, the switch will revert to the default state of OPEN. So in his code, this would result in the ATO running uncontrolled.

Therefore, my recommendation is to reverse the configuration/code so that the ATO is activated when the switch is CLOSED/DOWN.

Also, I would add a Defer ... ON as well for his ATO outlet. This would help filter out any false signals from waves, etc.

A high level float would disable the ATO when OPEN/UP and activate the email/alarm.

A low level float would disable the ATO when OPEN/DOWN and activate the email/alarm. The low float indicates a gross error and I do not try to make up for the loss as this would decrease the salinity.

It may be appropriate to disable other equipment as well, such as a skimmer, etc.

Todd

[kurt_n]

Just a quick thing about the code itself...

"If Switch1 is open then ON" should be "If Switch1 open then ON". The "is" shouldn't be there.

[Xcali1985]

Don't know how to answer it all, my head kinda hurts right now... However, if you have a solenoid valve coming from your RO then you want that to be in a closed state when no power is provided to the device. The reason being is that if you have power failure then you will have an open valve pumping RO water.