Heater redundancy planning and questions

Discussion in 'Equipment' started by JVU, Feb 4, 2018.

  1. JVU

    JVU Supporting Member

    I’ve been looking to add redundancy and safety to my heater system. I haven’t had any serious problems in many years, but I know lots of people have and I’m looking to be pro-active.

    - 500W Won Bros titanium heater without a thermostat plugged into Apex. Apex controls the on/off. No second control system. No second heater.
    - My tank is a RSR750 (200g total), rimless, with lots of surface flow.
    - The heater actually draws 650W according to the Apex. Not sure about the significance of this. During the winter when the house is as cold as I let it get, it is on half the time at most, so it is a little more than I need. When I look at the average power consumption in the winter from the heater it is about 250W, 300W at night.

    What I’ve read for safety:
    - Better to have 2 heaters half the power each so if there is a failure (on or off) of 1 heater you are still ok.
    - Better to have 2 different control mechanisms, one that controls the daily cycles and another set to kill power if it gets stuck on and overheats by a couple degrees.
    - The heaters with bimetal contacts are the most likely to fail on. Digital controller is more reliable.
    - I much prefer titanium to glass. They seem more reliable and much less likely to break, leak, or otherwise have a catastrophic failure.
    - People say replace your heaters every year, but I get the impression that is for the classic glass bimetal contact ones. I’d rather get good heaters and controllers and not have to change them every year.

    My plan:
    - Switch to 2 smaller titanium heaters, maybe 250W or 300W each.
    - Have my Apex be 1 of the 2 controller mechanisms, and either an integrated or separate controller be the 2nd.

    My questions:
    - The integrated controller mechanism on all the titanium heaters I’ve seen get ok to bad reviews. I don’t want something unreliable or inaccurate. Also would like to avoid one that is constantly shutting itself off before the tank reaches temp just because the sensor is on the tube. Do you guys know of any integrated heater/controllers that are accurate and reliable?
    - For external controllers, there are several on the market. I’d probably get 2, 1 for each heater. Considering the ink-bird since it gets good reviews. Ranco gets glowing reviews but I’m not interested in starting with parts and doing electrical work. The Finnex separate controllers get so-so reviews. If it is designed for saltwater use and I don’t have to do any DIY that is worth a lot to me. Any suggestions?
    - For titanium heaters, I’ve been happy with my Won, but they don’t seem to be popular. Finnex is the most popular but there are some complaints about voltage leak and failure. Are there some you guys like?
    - Do the digital controllers like the integrated ones or the external (like Ink-Bird, Ranco, or Finnex) deal well with lots of power cycling like would happen with using the Apex as the primary controller and the other controller as backup? I can’t find any info on this online, despite being a pretty important question in my mind.
    - Or would you suggest have the separate controller be the primary with the Apex as the failsafe backup? The 2 downsides to this are that the control probably isn’t as precise, and you can’t set Apex alarms for when current draw doesn’t match expected.
    - I was also thinking one of the 2 heaters would be the primary, set to the temps I want, and the second would only kick on if the primary can’t keep up, like 1 degree colder. The idea being there would be fewer cycles and the secondary heater and controller would see a lot less wear and be ready when needed. Any thoughts?

  2. iCon

    iCon Supporting Member

    FYI - Ranco wiring is super easy and you can buy them pre-wired. 2 adequate heaters on the same line into the Ranco. I’ve had Apex/RKE/etc, and would recommend saving the Apex outlets for lights/pumps.
    JVU likes this.
  3. JVU

    JVU Supporting Member

    Thanks iCon. I’ll check out the pre-wired Ranco, do you know where I could find it? One of my goals is to have redundant controllers so I would still use my Apex, either as backup or primary. Any idea if the Ranco would handle being power cycled 10 times a day ok?

    Now that the SB is over, anyone else have thoughts on this? What are other people doing?

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  4. Flagg37

    Flagg37 Officer at large

    I have two Finnex heaters on mine. I have the apex control them and just set the thermostats on the heaters to a couple degrees above what I set the temp to on the apex. That way if some how the apex tells them to stay on they can shut themselves off. I’ve found the apex temp probe to be only about 0.1 degree different from my two other thermometers, where as the Finnex thermostat was over a degree higher.

    I think the guy saying his Finnex was introducing stray voltage was in error. The heater works as a grounding probe and is actually advertised as such. Ive checked my stray voltage and it’s only 0.002.
    JVU likes this.
  5. JVU

    JVU Supporting Member

    Do you remember which of the Finnex heaters with controller you have, sounds like their thermostats handle power cycling fine? BRS tested some a couple months ago and found they shut themselves off frequently, taking several times longer to get to temp. I guess if you have their on-board thermostat set higher as backup it wouldn’t be as much an issue.

    Good to know they also work as a grounding probe, I didn’t know that.

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  6. Flagg37

    Flagg37 Officer at large

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  7. JVU

    JVU Supporting Member

    Regarding easy heater failsafes, I just saw this new product pre-order:


    It’s just a plug and magnetic temp probe that shuts off power when the temp is either too high or too low as a backup to your primary temperature controller. Simple with no other devices to setup or mount in your cabinet. The company is coming out with other easy smart plugs with optical sensors for example. Will be interesting to see if they work well.

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  8. scuzy

    scuzy Supporting Member

    I trust a ranco more that that one.

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  9. rygh

    rygh Supporting Member

    My suggestion:

    Heater 1: On Apex, and has its own temp control.
    Apex really controls normally, so temp control on heater set to 81, just as safety.
    So BOTH have to get stuck on to cook tank.

    Heater 2: In tank, and bit smaller. Temp set to 73 or so.
    This really never goes on unless one above fails.
    Since it never goes on, odds of getting stuck on are extremely low.

    So you get "enough" redundancy on both hot + cold side, with no fancy extra equipment.
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  10. Flagg37

    Flagg37 Officer at large

    Both of my heaters are setup like your first example but I’ve thought about doing what you said with the second one. My thought was that since the first one gets turned on/off so often that it should wear out much sooner. When it does I’d swap the second heater and put it in the first heaters place and get a new one that would go where heater two was. It would be a continuous rotation until they come out with one that never fails.
    JVU likes this.
  11. rygh

    rygh Supporting Member

    Two smaller heaters is also a good idea, lower loads = less heat, less spark, less likely to fail.

    And make sure to plug them into the high current relay plugs in the Apex.
    (Not that 10A is what I would call a big relay)
  12. JVU

    JVU Supporting Member

    I believe only the older Apex had that limitation, right? The new Apex EB832 uses the same for all outlets I think.

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  13. Ranjib Dey

    Ranjib Dey Webmaster

    Use apex to control both heaters. Go with glass heaters from any reputed vendors over titanium ones. Use a second controller to monitor tenperature only, if things go wrong you can use apex to turn things off , even if apex’s probe fails. This is the simplest but fairly redundant setup
  14. Flagg37

    Flagg37 Officer at large

    I’m curious, why do you prefer the glass heaters over the titanium ones. I’ve only had failures from glass heaters in my experience.
  15. Ranjib Dey

    Ranjib Dey Webmaster

    Titanium ones have higher fluctuations compared to glass ones. I dont know why, but if I have to guess, I'll blame it on cheaper thermister choice or probably some inteference by the metal body. Glass ones are more accurate. They fail sooner, but with proper monitoring thats manageable risk (known devil).
  16. Gablami

    Gablami Supporting Member

    I do this too. First heater with set temp controlled internally with safety being apex control. Second smaller heater on as backup if temp drops lower also on apex (but not as low as 73. Too low for me). Another benefit of two smaller heaters is fewer on/off cycles.

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  17. JVU

    JVU Supporting Member

    Titanium heaters are excellent if you use a separate controller/probe. The ones with integrated temp probe get poor reviews since they turn themselves off too quickly.

    So what I decided to try and installed tonight:
    - Primary 300W Finnex titanium heater (no integrated controller), controlled by Apex for 78.5-79.0F, with overheat shut-off backup by Ink-Bird set a couple degrees higher. This will wind up being on most of the time during the winter.
    - Secondary 300W Finnex titanium heater (no integrated controller) controlled by Apex for 78.0-79.0F. No backup at the moment, since it won’t turn on very often. But if the Ink-Bird works well I’ll probably buy one for this heater too (inexpensive and on R2R sale at BRS this weekend).

    The Ranco looked good but since I want to use the Apex as a high quality and reliability primary control, I thought the Ranco was overkill as a rarely used backup. If I was going to not use the Apex as primary control I would have bought the Ranco.
  18. Flagg37

    Flagg37 Officer at large

    Hmm, iirc that’s not what BRS found. I remember for sure that the neotherm ones (not glass or titanium) had the least fluctuation in temp. It was only like .1 degrees. But I thought that the titanium ones that I got were only about .5 degrees where as some of the glass ones were around 2 degrees. It’s been a while since I watched that video so I could be wrong though. I’ll have to look this up now. The fail point I had with my glass heaters was with the glass cracking. I had two where the glass cracked but thankfully I caught it before water got in to short them out.

    Just a quick note on this; Gabe I don’t know if you noticed but he uses the apex to control the on/off with the heater’s internal thermostat being set higher to act as the fail safe where you said you do the reverse. I don’t know how much of a difference doing it one way vs the other would make.
  19. rygh

    rygh Supporting Member

    A little fluctuation in temp is supposedly a good thing.
    It keeps the corals used to a bit, so in case of a heat wave or such, they do better.
  20. Gablami

    Gablami Supporting Member

    Ah, missed that. Don’t think there is a huge difference. From the BRS testing, neotherms temperature maintenance was so stable that I felt it a waste to have my apex cycle the device on and off repeatedly throughout the day. If the heater itself is really good at it, then let it do what it’s designed to do. Wear out the heater instead of the apex switch, since I try to replace my primary heater yearly (haven’t had that many years under my belt yet).

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