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Thread: Is controlling temp this tightly hard on the Apex?

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    Frequent Visitor rkpetersen's Avatar
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    Is controlling temp this tightly hard on the Apex?

    I've been using the Apex to control my system temperature as tightly as possible. I shoot for a maximum total temp excursion of less than 0.5 degrees F throughout the day and night. I currently have two 200W NeoTherm heaters on one EB832 outlet. The NeoTherms' internal thermostats are set to 80 degrees, which none of my programming ever exceeds. As you can see from the graph below, with lower home air temperatures, the Apex is activating the outlet/heaters as many as 70 times in a 24 hour period. (The slight drop in average temp on Oct 1 represents the season table effect. Also, I let it drift a bit higher on warmer days.)

    Clipboard01.jpg



    My question is this: Obviously this is stressful, to some degree, on the Energy Bar and heaters. My question is how much. I'm not worried about the heaters particularly, those are not so expensive and easily replaced if they fail, but I wonder what kind of wear this represents for the energy bar. I think I read something months ago, maybe from this forum, that indicated that the relays in the EB832 should be good for a million or more activations (which, at 100/day, would give me 27+ years.) So is this use reasonable, or excessive/risky?

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    Apex User zombie's Avatar
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    On the old EB8s, the electromechanical were good for about 100,000 operations (where ON, Then next OFF counts as an operation). I dont see documentation on the MTBF for the new ones so it could vary from the EB8. 100 times a day is good for about 3 years before they are likely to stick assuming they are exactly the same MTBF as the old energy bar.

    You might be an engineer if...You have no life and can prove it mathematically.

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    Frequent Visitor LobsterOfJustice's Avatar
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    Try just using one of the heaters. The constant swing is resulting from your heaters quickly raising tank temp, and then it falling again. If you use half that wattage, it should take twice as long to heat, and result in half the on/off cycles. Also, make sure your temp probe is seeing water that has been heated and circulated throughout the system. I generally place my temp probe in the first section of the sump and the heaters in the next section, so the temp probe is reading the system temp "farthest" from the heaters.


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    Frequent Visitor rkpetersen's Avatar
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    Thanks, those are both great suggestions, and easy to try out. I was actually already thinking about disconnecting one of the heaters and seeing how that works; 400W is a bit overpowered for the size of my system anyway. One issue though is that having too heaters in tandem adds a safety factor should one of them fail in the off position, which I'd lose with just one heater connected. I'll also try switching my controlling temp probe from the one in the sump to the one in the overflow, and see if that makes a difference.

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    Frequent Visitor LobsterOfJustice's Avatar
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    Quote Originally Posted by rkpetersen View Post
    Thanks, those are both great suggestions, and easy to try out. I was actually already thinking about disconnecting one of the heaters and seeing how that works; 400W is a bit overpowered for the size of my system anyway. One issue though is that having too heaters in tandem adds a safety factor should one of them fail in the off position, which I'd lose with just one heater connected. I'll also try switching my controlling temp probe from the one in the sump to the one in the overflow, and see if that makes a difference.
    To solve the failsafe issue, I have a second heater outlet which only kicks in if the first is not able to keep up. Programming is set 0.2 degrees lower than the main heater outlet. This also lets you run the main outlet in fallback ON but the backup in fallback OFF, so in the event of a failure you get some heating, but not too much to cook your tank if the heaters internal thermostat had failed.

    I also switch out my heaters based on the season as necessary - I run 2x 200w heaters on each outlet in the winter but cut them back to 100w heaters in the spring/fall and 50w heaters in the summer. To minimize swings, the goal should be to run the minimum amount of wattage necessary.


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    Quote Originally Posted by rkpetersen View Post
    Thanks, those are both great suggestions, and easy to try out. I was actually already thinking about disconnecting one of the heaters and seeing how that works; 400W is a bit overpowered for the size of my system anyway. One issue though is that having too heaters in tandem adds a safety factor should one of them fail in the off position, which I'd lose with just one heater connected. I'll also try switching my controlling temp probe from the one in the sump to the one in the overflow, and see if that makes a difference.
    Do a search on my posts about duel heater programming. I've set my two heaters up so each runs as primary for 12 hours a day and the other only kicks in if the primary isn't keeping up. That way you are running both heaters each day and know your backup heater is good. I also have an alarm set for if both heaters run longer than 10 minutes. That would tell me one has failed or is failing.

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    Frequent Visitor rkpetersen's Avatar
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    Found the thread and bookmarked it. That looks very interesting, I might do it. THANKS!

    First thing, though, I need to buy some different heaters. I didn't know it until just yesterday, but these NeoTherm 200W heaters have caused some complete tank disasters with the plastic case cracking opening, spilling some sort of hot molten epoxy into your tank water, killing everything and making your house smell like burnt plastic. Has also occurred with the 150W version. Most of the problems happened around 2014, the company supposedly redesigned them, the complaints seemed to decrease, but I just read about someone who had this happen with one manufactured just a year ago. It's too bad, I really like the concept of these heaters and the internal thermostat is top notch, but a potential disaster of this magnitude is not acceptable. I can handle a heater failing, either on or off, but not this. Sorry, rant over.

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