Chiller duty cycle?

[davidncbrown]

This is kind of along the lines of an existing thread, but I didn't want to hijack it so I made my own. I just hooked up my 1/15 current chiller today and I had some questions for you peeps. I got it for a really good deal from a guy, $50, but on the back it said the manufacturing date is 06. He said he bought it new and has had it for a year. How long do these chillers usually last before they need service (new refrigerant, etc.)?

 

Also I installed it today using the stock NC24 pump because I didn't have anything else that would fit. It seems to be cycling on every couple of minutes, it stays on for a minute or so and then turns off. I know this is bad for compressors (and who knows how much it cycled on its previous owners tank...). I have the pump in chamber 2 of the back filter section, and then I placed the return line into chamber 3 where the circulation pump is. I only set the chiller to 81degrees and its having difficulty keeping it where it should be (ie it cools it down beautifully but it heats up really fast)... Is there anything I can do to fix this horrendous duty cycle of 2 mins off and a min on? I don't even have the lights on right now and it's cycling this bad....

 

Edit: I had replaced the stock pump with a MJ1200 a couple months back. The only other pump besides the stock I have lying around is the power head I use for mixing saltwater and that wouldn't fit anyways. So thats why I'm using the stock NC pump.

[HankB]

Where are you measuring temperature? Is this an indicator on the chiller itself or in your tank?

 

It sounds like there is insufficient flow through the chiller. The water inside the chiller cools down causing it to shut off (stop chilling) until warmer water is pumped in.

 

-hank

[davidncbrown]

Where are you measuring temperature? Is this an indicator on the chiller itself or in your tank?

 

It sounds like there is insufficient flow through the chiller. The water inside the chiller cools down causing it to shut off (stop chilling) until warmer water is pumped in.

 

-hank

 

 

Ya I think you're right. I've been messing with it and I think I have it fixed. I have a coralife digital therm in one end of the tank, a glass therm in the other, and now the temp gauge on the chiller. I calibrated the temp probe on the chiller +1, and then I set the differential to 4 instead of 2. I think you're right that water isn't being circulated fast enough. The digital therm and the glass both say about 81.5 and the temp on the chiller says 84. The chiller only stays on for a minute so its not really chilling that much water before it's probe says its down to 81. I think by changing the differential I'm giving more time for the tank to "warm up" (the newly chilled water to mix with the warmer tank water) since it equalizes slower than the water that's in the chiller heats back up. I don't know if that made any sense, but I think this is working... Fingers crossed.

[Hellzbellz]

SPS20 had some great info pulled from Current on their chillers. He'd be a great resource to find out the duty ratings. You shouldn't have to "Replace" teh refrigerant, per se. If you have a leak, you'll need to top off, but otherwise, it should be maintenance free (make sure the coil stays clean, that's the #1 killer of HVAC units).