Q: Chiller control options?

[Ziggy_Zeigler]

Hi -

I am working on setting up a larger tank than I have ever attempted (150G). My current tank (75G) has utilized fan/evaporation for temperature control during the warmer seasons. This time around I would like to use a real chiller (e.g. 1/4 HP JBJ Arctica). I currently have a controller (Ranco) that has served me very well over the years. So the question becomes, can I continue to use my Ranco with a chiller like the JBJ? If so, do I actually set this up so that the power the JBJ is interrupted during the heat cycle or do I just cut off the chiller supply pump?

Thanks in advance for any advice/guidance.

 

[washingtond]

@Ziggy_Zeigler wrote:

I also use a JBJ Arctica Chiller and have been for the past four years without any problems. I use the control built into the chiller which is set to come on at 80 degrees and goes off at 79. The tanks heaters are controlled by the Apex controller and comes on at 78 degrees or lower and off at 78.5 degrees. There is a one degree temperature gap between the two controllers for safety.

I would never cut the water flow to the chiller since the temperature sensor is built in. If you Ranco is a two stage it can control both the chiller an heaters by turning the power on and off to each of them according to the temperature. I would suggest that you calibrate the temp on the chiller to read the same as the Ranco in this case. This will also prevent the heater and chiller from being on at the same time.

 

[Ziggy_Zeigler]

Hi -

Yes, the Ranco is a dual stage controller. Does it harm the chiller to have the power cycled at that kind of duty cycle? Is there a reason that you keep such a warm tank given that you have capability to keep a tank at something more like 76?

Thanks - Ziggy

 

[washingtond]

@Ziggy_Zeigler wrote:

It should not harm the chiller to keep the power off for a short period of time, long term (several days) I do not know since I don't know what type of memory is being used to store the settings when the power is off. What temp were you planning on regulating your tank too? I chose 78 to 80 when we first started our tanks and just left it there. You could, and many do, run at a lower range such as 76 to 78 if you like.

What I would do is lets say you wanted to keep your tank between 76 and 78. I would set the Ranco heater to come on at temps <75 and the chiller on at 77. I would set the Chiller itself to 78 which means that it will shut off at 77 under its own control. I would try this out and make sure there are no conflicts. In other words I would make sure that the chiller has power most of the time even when it is not running. The Ranco should make sure that the heater and chiller are not on at the same time. The most important thing about this setup is the temp calibration of the chiller and Ranco must be the same and track each other up and down.

The objective is to keep power on the chiller most of the time and let it determine when it needs to chill and have the Ranco completely control the heater. Hope this helps.

 

[Ziggy_Zeigler]

Hi -

Yes, that definitely helps. I will try your suggestions once I get this system setup. I was thinking a target temp of 76 was desirable (but I have never been able to achieve that using fans...so I am stuck with an 80 set point currently without a chiller).

Thanks again for the help.