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mmullaly
05/04/2011, 06:23 PM
I want a fail safe for my ATO.
Please check my program, it doesn't seem to work, it just cycles the ATO solenoid on/off several times a second. My program is set to run the ATO for a 5 minute minimum and 10 minute maximum. Please let me know what I'm doing wrong.

Thanks,

ATO Outlet

Set OFF
If Switch1 CLOSED Then ON
Defer 000:30 Then ON
Defer 005:00 Then OFF
If Outlet ATOCheck = ON Then OFF

ATO Check Virtual Outlet

Set OFF
If Outlet ATO = ON Then ON
Defer 010:00 Then ON

swearint
05/04/2011, 07:50 PM
Have you checked the solenoid with the outlet set to Manual ON? The Apex is only accurate to one second, so I am suspicious that it could oscillate as fast as you indicate. If the solenoid is good, I suspect the issue is due to a circular reference. You have ATO dependent on ATOCheck which is dependent on ATO.

You could do the following:

[ATOLimit]
Set OFF
If Switch1 CLOSED Then ON
Defer 010:00 Then ON

[ATO]
Fallback OFF
Set OFF
If Switch1 CLOSED Then ON
If Outlet ATOLimit = ON Then OFF
Defer 00:30 Then ON
Min Time 5:00 Then ON

This should run for a minimum of five minutes and a maximum of ten minutes. However, if [ATOLimit] gets set to ON before Switch1 changes to OPEN, [ATO] will not run again without manual intervention to reset. I am not sure how the highlighted Defer will behave with the Min Time. If needed to prevent false starts, create a virtual outlet for Switch1 and move it there.

Todd

mmullaly
05/04/2011, 08:56 PM
This makes sense. The only problem is that I don't want to have to depend on the float switch. I basically wrote the ATO Check to prevent a float malfuction. This has happened once where my float got stuck and my sump overflowed. So, how can I adapt your code to not depend on the status of the float switch?

Thanks

swearint
05/04/2011, 09:10 PM
This is what I do:

[ATO_Allow]
OSC 000:00/030:00/450:00 Then ON

[ATO]
Fallback OFF
Set OFF
If Switch1 CLOSED Then ON
If Outlet ATO_Allow = OFF Then OFF


[ATO_Allow] creates a 30 minute 'window' every eight hours in which [ATO] can run if the float switch calls for it. This won't absolutely protect against a failed switch, but limits the run time. I also use an independent high level sensor that opens a relay and cuts power to my solenoid.

Todd