Programming Heater Outlet??

[miyzfrider]

I'm still not clear on how best to program a heater outlet. The heater on my 90G is down in the 25G sump. It's a Fluval E-300 (300W). I have set the temp on the heater to 81degrees. My Apex program for the heater outlet looks like this...

Fallback ON
If Temp < 77.9 Then ON
If Temp > 78.1 Then OFF

Here is a one day graph of the temp fluctuations with this program and setup.

https://lh5.googleusercontent.com/-kbTPA1oH7ZY/Ty6xdXKhucI/AAAAAAAAAXc/z2adSqa8UPk/s800/temp_graph.jpg

Is this normal?? I'd sure like to get the temp to maintain within a .1 or .2 range rather than .4. Could this be a heater issue (undersized), or how can I modify my program to make that possible, without the heater turning on off too frequently.

[dlp211]

Your code has a built in .5 swing. It turns on at 77.8, then it climbs until it hits 78.2. This means your tank will be 77.8, 77.9, 78.0, 78.1, and 78.2 degrees.

To tighten your temp you can use one of the following:

Fallback ON
Set OFF
if temp < 78.0 Then ON

or

Fallback ON
if temp < 78.0 then ON
if temp > 78.0 then OFF

The first will only have temps 78.0, and 77.9. The second will have 77.9,78.0 and 78.1. Now you will see some dips and spikes outside of these ranges just due to the rate of heat loss vs heat in at any given point which really isn't that big of a deal.

HTH

Also, your are only polling the temp every 10 minutes or so, so these graphs aren't a perfect representation, but they are pretty darn close. The graph around FEB4/0800, is the most accurate representation of what your temp is actually doing. If you poll more often, your graph will look more and more like that.

[miyzfrider]

I really appreciate the insight!

One question, if I program either of those, will my heater outlet turn on and off too often due to it not having a range? Should a defer or min statement be used to make sure X number of minutes pass before it cycles? In a 90 gallon aquarium, where the temp probe is at, I don't think the temp shift will be sudden. Just don't want to "stress" apex outlet or heater.

[dlp211]

Your heater will cycle on and off more often with either of those. That is the price of having a tighter temperature.

I personally don't use a defer, but if you really want to, I would set it to no more then a minute. Also, if your heaters are plugged into the TRIAC outlets, 1,2,3,5,6, or 7, then it won't stress the Apex any.

Heaters are simple devices, I don't believe constant on/off cycling is going to damage them either.

One thing I would watch is relying on your heater thermostat in case you go to fallback mode.

[miyzfrider]

Thanks. The only way the heater thermostat would take over is if the Apex somehow left the outlet on and didn't shut down at 78.1. In that case, the thermostat of the heater is set to 81, just to ensure I don't cook the tank. Could it fail?? Sure, but I don't know what another option would be and it would require the Apex to fail first.

Again, I appreciate your insight!!

[dlp211]

If the Apex goes to fallback mode your heater will rely on its internal thermostat which you have set to 81. Ideally, your heater will then turn itself on and off at 81.

I personally don't trust heaters as I have never had one that has worked appropriately. I put a Ranco controller in between my EB8 and my heater, this way if my Apex goes to fallback mode, the Ranco takes over.

I also have a 180 gallon tank that is slowly approaching 1000's of dollars of livestock, so the extra 100 bucks or so for the redundancy was a no brainer.

YMMV depending on the size of your tank and amount of livestock in it.

[miyzfrider]

A question comes to mind then, how often will the Apex go into fallback mode? I have only had mine for about 2 weeks and haven't had any trouble thus far. What really will cause that to happen? I know it's a loss of communication with the controller, but that would only happen if the cable becomes disconnected or a power failure, in which case everything goes down all together till I get the generator going. :-) Is a fallback going to happen normally on occasion?

[RussM]

Regarding the use of Defer to reduce heater cycling... think about it this way: tens of thousands of people use heaters with built-in thermostats without any other form of heater control. Those heaters bounce on and off around the set point of the thermostat.. it does not cause undue wear and tear; heaters are made to be operated that way.

[RussM]

miyzfrider, Fallback is an emergency mode - it's not something that happens regularly. The assigned Fallback setting kicks in only if the EB8 loses communications with the controller.

[karsseboom]

Why do you want your temp so stable?

http://www.reefcentral.com/forums/showthread.php?t=2127749

[miyzfrider]

Maybe I don't. :). Interesting reads. Thanks for the enlightenment. Maybe what I should do is allow the temp to drop to 76 or so at night and come up to 78 or so during the day.

What would that program look like?

[miyzfrider]

Let me officially ask that question then, how would you program your heater to work at one temp during a certain period of the day, and at another temp for a different time period? I assume some virtual outlet programming may be needed and I'm new to this so I'm not sure.

[dlp211]

Set up virtual outlets like this

[8to10]
set OFF //set outlet to be off
if time 08:00 to 10:00 then ON //if the time is right turn the outlet on
if temp > 76 then OFF //if the temp is wrong turn it off

[10to12]
set OFF
if time 10:00 to 12:00 then ON
if temp > 78 then OFF

[12to16]
set OFF
if time 12:00 to 16:00 then ON
if temp > 80 then OFF

etc to cover the whole 24 hour period in the time intervals you prefer.

Then your heater code will just look like:

[heater]
Fallback ON //this is so your internal thermo can take over in case Apex loses commo
Set OFF //set the heater to off
if outlet 8to10 = ON then ON //check to see if the time is right and temp is right to be on
if outlet 10to12 = ON then ON //same
if outlet 12to16 = ON then ON //same
etc

[swearint]

It is a bit cumbersome, but yes virtual outlets are necessary.

[Night_Low]
Set OFF
If Temp < 76.0 Then ON
If Time 07:00 to 19:00 Then OFF

[Night_High]
Set OFF
If Temp > 78.0 Then ON
If Time 07:00 to 19:00 Then OFF

[Day_Low]
Set OFF
If Temp < 78.0 Then ON
If Time 19:00 to 07:00 Then OFF

[Day_High]
Set OFF
If Temp > 80.0 Then ON
If Time 19:00 to 07:00 Then OFF

[Heater]
If Outlet Night_Low = ON Then ON
If Outlet Day_Low = ON Then ON
If Outlet Night_High = ON Then OFF
If Outlet Day_High = ON Then OFF

I think this will do the trick, but I have not tested it. Basically, the four virtual outlets define the time periods and temp ranges. During the day, both night outlets will be OFF and have no effect. Vice versa during the night. Assuming it is during the day and the temp drops below 78, Day_Low is TRUE/ON and Heater will turn ON. It will stay ON until the temp rises above 80 and Day_High becomes TRUE/ON, thus turning Heater OFF. Again, vice versa for the night.

Todd

[dlp211]

swearint, your code would work but there is no need to program a Day_High or Night_High, just change [heater] to:

[Heater]
Set OFF
if outlet Night_Low = ON then ON
if outlet Day_Low = ON then ON

[swearint]

Depends on how you want to operate the heater. I use a range rather than a single setpoint.

Todd

[miyzfrider]

That's awesome guys. Do you see the benefit in doing this to allow the temp to fluctuate within a 24 hour period? Reading some of the threads related to temp swings being ok made me reconsider the whole idea of wanting the temp to hold constant. Makes sense that in an ocean environment the temps would swing throughout the day with daylight heating and night time cool downs.

Would you concur with that approach for heater function?

[swearint]

I actually just use a single range: 79.0 +/-.3 or 79.3 to 78.7. But, the heater operates over the low portion (78.7 to 79.0) and the fans over the high portion (79.3 to 79.0). So, due to the heat from the lights, my tank fluctuates naturally.

Todd

[miyzfrider]

I only have 4 T5's on my 90G so the lights don't really heat it up that much. So the only way I'm going to get the temps to go up during the day is to use the heater.

Thanks for the programming ideas!

[Tetra84]

not to hijack.. but how should I program 2 heaters? do I want to keep one off until the event that the first one dies or set them both on the exact same program?

[miyzfrider]

That's a good question too as I've considered a second heater, both as backup, but also to help the temp stick a bit closer and easier to the temps I desire.

[dlp211]

not to hijack.. but how should I program 2 heaters? do I want to keep one off until the event that the first one dies or set them both on the exact same program?

I have 3 heaters for my 180. I turn them all on at the same time and off at the same time. If one of your heaters dies then it is no big deal. In order to see if one of your heaters died pay attention to your amp graph.

I had two of my heaters die on me overnight one time, I noticed the minute that my heaters turned on in the AM and I was looking at the display, normally my Amp would be around 8 and it was around 3. I stuck my hand in and two of them were dead. Bought some eheim jagers to replace them and all is well now.

If you wanted to, you could use the defer statement to keep them all from coming on at the same time, but it doesn't make any sense not to run them at all because if they never run unless there is a failure, then you never know if they backup has also failed.

[Fishypapa]

Old thread I know but I thought since I just bought an Apex and probably a bunch of others did to over the Black Friday weekend, that it might be nice to bring it up again.
I have 2 heaters and this really helps.

[Krazie4Acans]

I actually just use a single range: 79.0 +/-.3 or 79.3 to 78.7. But, the heater operates over the low portion (78.7 to 79.0) and the fans over the high portion (79.3 to 79.0). So, due to the heat from the lights, my tank fluctuates naturally.

Todd

Todd could you possibly post your code for this setup? I to need to run fans at high temp and heater at low and just wanted to see how you did this. Did you use virtual outlets and just change the code for the heater and fans to use those virtuals?

I have 3 heaters for my 180. I turn them all on at the same time and off at the same time. If one of your heaters dies then it is no big deal. In order to see if one of your heaters died pay attention to your amp graph.

I had two of my heaters die on me overnight one time, I noticed the minute that my heaters turned on in the AM and I was looking at the display, normally my Amp would be around 8 and it was around 3. I stuck my hand in and two of them were dead. Bought some eheim jagers to replace them and all is well now.

If you wanted to, you could use the defer statement to keep them all from coming on at the same time, but it doesn't make any sense not to run them at all because if they never run unless there is a failure, then you never know if they backup has also failed.

Do you run all 3 heaters off of one outlet and a splitter or off of individual outlets?

Krazie:jester: