Aquacontroller Temp Probe Malfunction???

[Rascal]

Running an ACJR - <6 months old.

 

Notice a few minutes ago that the Chiller was on. Thought that was odd for this time of day. Except in summer it usually only comes on when the Halides do. Stuck my finger in the tank just to make sure . . . yikes that's cold!

 

I stuck an old glass thermometer in the tank and it reads 68 degrees.

 

I quickly unplugged the chiller, turned the heater on manually, and turned on 2 of the MH to help get the temp up.

 

Then I started trouble shooting. The display says the temp is 123 degrees. Thus the decision to turn on the chiller to get it down. The temp probe was in exactly the same place it always is -- submerged in about 6 inches of water, right next to the PH probe.

 

Looked at the Data Log and revealed the following: Up until 0200 everything was normal. Temp stays b/n 79-80. At 0300 and every hour since, it reads 123.

 

I tried disconnecting and reconnecting the temp probe cord, disabling and re-enabling the temp probe on the device, and disconnecting and reconnecting the power cord. No change. It still reads 123.

 

Any thoughts?

 

Advice?

 

I will copy this in an email to Neptune, but I can't call them now b/c it's the weekend.

[phisigs79]

temp probe is bad. happened to me once and thats what it was. Order 2 when you do in case this happens again.

[dandy7200]

I had a probe go bad too and it did exactly as you describe. I invested in a expansion module and now run 2 temp probes.

[YBeNormal]

So, would it be a good idea to add a couple of lines of programming to override any obviously out of range temps, say 65 degrees on the low end and 100 on the high end? In other words, turn the heater off if the temp reads less than 65 and turn the chiller off if temps read greater than 100?

[stratos21ss]

..be careful not to lose your failsafe for a broken heater that is not turning off.

[Rascal]

So, would it be a good idea to add a couple of lines of programming to override any obviously out of range temps, say 65 degrees on the low end and 100 on the high end? In other words, turn the heater off if the temp reads less than 65 and turn the chiller off if temps read greater than 100?

 

Apparently so. A quick search on the neptune forum on rc revealed that this is a relatively common problem, although Curt says <1%. http://www.reefcentral.com/forums/showthre...ght=temperature

 

One reefer offered these suggestions for redunancy and backups:

 

Sure...

 

"RT " is used to access the seasonal temperature tables (they vary slightly over the year, warmer in the summer and a slight bit cooler in the winter so simulate changes in ocean temperature).

 

If Temp < RT+-4.0 Then HET OFF // If the temp falls below the value in the (seasonal table - 4.0 F) then turn off HET

 

If Temp > RT+4.0 Then COL OFF // If the temp raises above the value in the (seasonal table + 4.0 F) then turn off COL

 

and

 

If Temp < 73.0 Then HT1 OFF // If the temp reading is lower than 73.0 F then turn off HT1

 

Max Change 005 M Then HT1 OFF // Once the HT1 device is turned off, don't let it turn on for at lease 5 minutes (Max Change holds the device in the indicated state for the specified amount of time even if another program statement would cause it to change)

 

If Temp < 73.0 Then HT2 OFF // If the temp reading is lower than 73.0 F then turn off HT2

 

Max Change 005 M Then HT2 OFF // Once the HT2 device is turned off, don't let it turn on for at lease 5 minutes

 

I also pulled out a Ranco that I had in reserve. I think I will hook this up to the chiller outlet on the DC8 and set it to only turn at at temp >77. For runaway heaters, I still think the best solution is several small ones rather than one big one.

 

Bright side for me -- looks like I caught it in time -- no massive death as far as I can tell.

Edited January 5, 2008 by Rascal

[flowerseller]

Sounds like I'll have a fire, a coctail, and do some recoding this evening.

 

Thanks for the free research.

[YBeNormal]

..be careful not to lose your failsafe for a broken heater that is not turning off.

 

Good point.

 

I had already considered adding some fail-safes to handle situations where probes fail or get unplugged but wanted to do some testing before posting my ideas. What I wanted to try was unplugging probes to see what the ACIII registered, figuring that might simulate a failed probe condition. If so, that value could be established as the absolute trigger to override other settings rather than setting a range value. If a failed or missing temp probe will always register 123 degrees for example, then that setting would be used to turn off the chiller.

[stratos21ss]

Sounds like I'll have a fire, a coctail, and do some recoding this evening.

 

lol..hopefully in that order and not - have a coctail, do some recoding this evening, and have a fire.

[dhoch]

This is why an alarm state is good... Setting the alarm state to turn a bunch of stuff off or let you know (via Text Message) is a great way to go.

 

Dave

[lanman]

While on the topic... what would you all consider 'emergency' temperature, high and low? i.e. - at what temperatures should my AC-III give me a call? I've heard that some xenia's will die at >83 degrees. I've only received one shipment by mail - that was some anthelia. The water was 68 degrees. The anthelia survived. I've never had one of my tanks go below 76, or above 82; so I don't know much about the effects of temperature extremes. (yet)

 

bob

[dhoch]

I have mine set for like 76 and 82.... but I don't like big temp swings... that's overly cautious on my part.

 

Dave

[jamesbuf]

This is why an alarm state is good... Setting the alarm state to turn a bunch of stuff off or let you know (via Text Message) is a great way to go.

 

Dave

 

 

I agree completely. That was the main reason I upgraded to the ACIII. Tagging along to see other possible remedies.

[dhoch]

Now I don't use a chiller so that part is lost on me, but I do use heaters and I have redundant temp gauges (one in main tank and one in the sump).

 

If the temp gets too high in the sump that can shut of the heaters (Also the heaters are set some where so they don't get to high as well)... Did I say I was into redundancy.

 

Dave

[Rascal]

Well, I got an email from Curt at Neptune and unfortunately the warranty on the probe is only 90 days. I am pretty sure I bought mine in Sept. So I just ordered a replacement off of the website for $39 incl shipping. Bummer.

 

It just hasn't been a great day for my reef. Just a few minutes ago I heard a clicking sound coming from one of my MJ mods - kind of like it was just starting up except there was no reason it should have been off. Upon closer inspection I saw that my bi-color blenny had decided to investigate its last little cave. Took a prop to the head and then got jammed in there. RIP little blenny.

 

At least the anemones appreciated the little late night snack though.

[Rascal]

Well, I got an email from Curt at Neptune and unfortunately the warranty on the probe is only 90 days. I am pretty sure I bought mine in Sept. So I just ordered a replacement off of the website for $39 incl shipping. Bummer.

 

Curt was nice enough to offer to cover the replacement anyway even though it was technically out of warranty. That is the sort of far-sighted thinking and fairness that some retailers in this hobby could use more of. As disappointed as I was that the temp probes can fail so quickly, I was even more impressed by this.

 

So impressed that I decided to just do now what I was going to do eventually anyway, and I upgraded to the ACIII - picked it up at BRK last Thursday. Very happy with it so far.