Titanium Heaters

[iCon]

Started using a Finnex 500w which comes with a built in temp control. I have to turn it up to about 82 on the dial in order to achieve 78 in the tank, but it appears stable. They claim to have some brains in these heaters, so I’m wondering if adding in my standard-protocol Ranco will conflict or potentially damage the Finnex?

Thoughts? Open to suggestions as well re: titanium heater brands etc. as this was inherited.

 

[thanh510]

From what I've been reading on reef2reef,is that it's best to use the Finnex to control and mediate the temperature and then use Apex or Ranco for emergency shut off. This preserves the relay on the Apex and Ranco too.

 

[iCon]

From what I've been reading on reef2reef,is that it's best to use the Finnex to control and mediate the temperature and then use Apex or Ranco for emergency shut off. This preserves the relay on the Apex and Ranco too.

Thanks what I was seeing to, so perhaps it’s just expanding the range a bit on the Ranco. Seems to make sense.

 

[sfsuphysics]

See I would think just the opposite. The Ranco is not something you should worry about, it's the heater's controller that is usually the worst problem, so that's likely to fail first, so once that does then you really are down to a single control element in the Ranco, so as long as you don't actually need to use the heaters controller it won't wear. As long as you don't have an incredibly small hysteresis on the Ranco it should outlast the heater, that was something the BRS guys did with their first foray into with the Apex where I think they set it to 0.01 degrees so that thing was going on and off crazy fast.

Full disclosure I'm really basing this off the incredibly old idea of a bimetallic element, something that physically moves/reacts to the change in temperature, I"m not sure how the electronic dohickies work, if having current flow through them wears them out even if they don't do anything.

 

[Flagg37]

I really don’t think one way is better than the other. I have my apex control the temp within 0.5 degree and the thermostat of the heater set 1 degree above that. The biggest thing is just to have at least two layers of redundancy.

I also use the Finnex heaters and saw the same difference in temperature.The thermostat reported 80 degrees when the apex reported it was only 78. Finding out the actual temperature would make good use of that new club thermometer.

 

[rygh]

FYI on failure points:

High inrush current.
Initially, when the heating element coil metal is cold, it conducts a lot of current until it heats up.
So turning it on a lot damages it.

Relay turning off
When the relay opens, the coil acts a bit like an inductor, so you end up with high voltage across the relay.
There are usually, but not always, protection circuits.

Relay contact corrosion
Corrosion builds over time on the contacts.
That poor contact starts to add resistance, causing heat at that location, and sometimes a spark gap.

The above relay problems can cause relays to weld themselves on.

Relay spring breaks
It is a carbon steel spring. It can rust.

Hot electronics
Heat is the enemy of electronics. Causes many problems.
Nothing like putting electronics IN a heater....

Leaks in temp sensor
Most temp sensors use a difference in electrical resistance to measure temperature. (Thermistor)
That resistance can change if it is not VERY well sealed.

Moisture in electronics
Interestingly, pure water is used to clean electronics, and is not damaging.
But with dust, a bit so salt, and everything else, moisture can be bad news.

 

[iCon]

FYI on failure points:

High inrush current.
Initially, when the heating element coil metal is cold, it conducts a lot of current until it heats up.
So turning it on a lot damages it.

Relay turning off
When the relay opens, the coil acts a bit like an inductor, so you end up with high voltage across the relay.
There are usually, but not always, protection circuits

Thanks @rygh - I’ve generally kept a heater’s internal thermostat such that it got the water to about 79-80, then controlled it with the Ranco from there to get to 77-78.

Usually set the Ranco’s to +/- 1*, and it sounds like maybe even a bit wider would be a good idea. I know we all like control, but keeping water temp nearly constant is probably overkill.

 

[JVU]

I discussed my approach to heaters in some detail in my tank journal:

JVU’s RSR750

I like the zoa Alcatraz, I guess the inverted cone shape keeps them on the rock? You just have to deal with the ones that free-float once in a while? So are your heater elements plugged into your Inkbirds, which are plugged into the Apex? This is how I set mine up, using Apex as the kill switch...

www.bareefers.org

I want the more accurate sensor and better quality switch/relay controlling the system, with the less accurate and reliable one as the backup. Plus the better controllers also have better alarm features. So I have my Apex controlling, and my in-line InkBirds as backup controllers.

 

[RandyC]

I discussed my approach to heaters in some detail in my tank journal:

JVU’s RSR750

I like the zoa Alcatraz, I guess the inverted cone shape keeps them on the rock? You just have to deal with the ones that free-float once in a while? So are your heater elements plugged into your Inkbirds, which are plugged into the Apex? This is how I set mine up, using Apex as the kill switch...

www.bareefers.org

I want the more accurate sensor and better quality switch/relay controlling the system, with the less accurate and reliable one as the backup. Plus the better controllers also have better alarm features. So I have my Apex controlling, and my in-line InkBirds as backup controllers.

I actually take the opposite approach for a few reasons.

- I don't consider a tight temperature range to be beneficial or necessary. A range of 2F is fine by me. Ranco usually keeps it in about a 0.7-1.0F range anyway.
- I prefer the supposedly more reliable controller to be the failsafe, last ditch resort. I would hate that the cheap backup failed and I didn't know because it was actually never being tested/used. And if you're using the actual heater's thermostat for the fail-safe, just know that some heaters break just sitting there, in the garage, not even plugged in.
- Heaters switch on/off a lot. I'd rather not tax the relay on the part that's more expensive & can affect other equipment if the unit fails. One plug failing shouldn't affect the others, but who knows.
- Have you ever switched out an EB832? It's awful. As far as I know, there's no way to copy a whole EB832 configuration to a newly replaced one, so it's a lot of manual work. There's room for human error. So I'd rather be more likely to swap out the easy to configure part (in my case Ranco or Heater) than the more costly, more of a headache part.