Apex heater programming

[Mjrenz]

I have 2 heaters for my tank and I want to set them up in a lead/lag configuration. One heater by itself is plenty to heat my tank and I do not want them running at the same time because it will overload the ups I have my eb832s plugged into. I'd also like the newer of the two heaters to turn on if the older heater fails and the tank gets too cool. Every heater failure I've experienced has resulted in the heater failing open and not heating but I did add a line for both to turn off if the temperature gets too high because one gets stuck on. I came up with programming for both of them and I think I have it right but I'd appreciate any suggestions if I missed something. I've attached a screenshot for both of them. Also, I will be taking some advice I already got here to manage power outages with a relay and breakout box instead of the power to the apex controller, I'm just waiting for everything I ordered to arrive

 

[Servos]

What is the purpose of the "If Dow S---TFS then" statements (line 3) of the program? It looks like it would cause Heater_7 to potentially cycle more than the temperature range you specified, while 2_Heater2_8 wouldn't turn on Thurs - Saturday.

If the DOW statements were removed:
outlet 2_Heater2_8 would be the primary, forcibly turning the outlet off if the tank hits 80*c and turning back on when 7.9 and at least 5 minutes have gone by. Perhaps add a "If Temp < 78.0 then ON" would help after "Set ON" to reduce cycling every 5 minutes if the heater gets stuck on.

outlet Heat_7 would look fine with DOW removed.

 

[Mjrenz]

So far it seems to be working. The code on line 3 causes one heater to be on Thursday through Sunday and the other heater to be on Monday through Wednesday to accomplish the lead/lag configuration I'm looking for. I did it that way to reduce the relays on my apex from cycling too often and only switch the lead twice per week. The built in controllers on my heaters do a pretty good job keeping the temp between 77 and 78 and I have my probe alarms set at 76 and 80 so I'll be notified if one gets stuck on and I can take care of it. It should take longer than 5 minutes to cycle also because the 5 minute delay wouldn't start until the temp dropped back below 80

 

[BryanM]

I no longer have an apex so I can't look up my programming. But basically:

Apex temp was the failsafe to cut power at 80 degrees
I ran two helios controllers set to turn on at 77, off at 78

And I had apex programming where one controller was active from midnight to 11:59am, the other was 12pm to 11:59pm.

I highly recommend a controller for each heater for more fault tolerance.

 

[Mjrenz]

I no longer have an apex so I can't look up my programming. But basically:

Apex temp was the failsafe to cut power at 80 degrees
I ran two helios controllers set to turn on at 77, off at 78

And I had apex programming where one controller was active from midnight to 11:59am, the other was 12pm to 11:59pm.

I highly recommend a controller for each heater for more fault tolerance.

I'm using Aquatop heaters, they have a built in temperature controller with a remote temperature sensor and do good job of keeping the temperature swing to less than 1 degree, I am only using the apex as a failsafe. I'm definitely trying to limit the cycles on the apex's relays