Lab liquid chiller unit internal views - Perkin Elmer C6 by Fraser - Page 1
Forum section: electronics / general

author: Fraser
author_rank: Super Contributor
timestamp: July 20, 2016, 02:15:35 pm
content: Something a little different from me today.I saw a Perkin Elmer C6 Chiller unit for sale at one of my regular equipment recyclers and decided it was cheap enough to buy and play with. It cost me just £16 and these sell for over $1000 so not bad really.The unit is basically a dinky compact refrigerator that contains a heat exchanger to cool a fluid circulation system. The C6 contains its own fluid pump to circulate the cooling fluid around the cooling system. This is quite separate from the refrigerator cooling pump and circuit.The IN and OUT connectors are for the cooling circuit hoses that connect the chiller to whatever needs cooling. It is a close circuit with a top up access port on the top of the unit (grey cap). A 1:1 glycol/water mix is used in the cooling circuit.This would make a great fluid chiller for fluid cooling an overclocked PCSpecifications are as follows:Chiller Range - User selectable for -5C to +25CMax Power - 450VACooling Power - 180WCooling agent - R134aHose Connectors - EURO quick connect typeThe refrigerator module is a 1.25HP DANFOSS PL50FX Made in GermanyAll in all a really tidy little chiller unitFraser

author: Fraser
author_rank: Super Contributor
timestamp: July 20, 2016, 02:20:12 pm
content: More pictures

author: Vgkid
author_rank: Super Contributor
timestamp: July 20, 2016, 03:35:43 pm
content: Thanks for the teardown. We had an Eheim aquarium filter.

author: SeanB
author_rank: Super Contributor
timestamp: July 20, 2016, 04:56:25 pm
content: Absolutely standard pond pump there, just with a different inlet moulding. They even left the filter foam in from where it was used in the pond pump application. Will bet you Fraser the shaft of the pump is worn, along with the impellor, but those are a stock Eheim part.I use a similar one at work, but as it generally lasts around 5 years in use I just replace the whole pump with a new one when it gets too noisy. Quicker than ordering the ceramic shaft and impellor, as they are off the shelf at the garden centre.As a bonus I get a 9m extension cord for free, as I only need 50cm of the power cord, they come with a 10m very nice ultra flexible outdoor rated power cable.

author: Fraser
author_rank: Super Contributor
timestamp: July 20, 2016, 05:47:07 pm
content: I think I have struck lucky with this unit.I attached a 2m hose loop to its inlet and outlet ports and then filled its reservoir with water for a test.Applied power and tried to switch it on....well it came on then died....... BUT it was just the front panel rocker switch that had failed. I disassembled it and found that the rocker has cracked making it unreliable.When I repaired my STANLEY air compressor I bought several rocker switches and so had what I needed in stock for the chiller repair. A new rocker switch was fitted and the unit now works perfectly. It runs very quietly and the pump self primed. The air self vented from the cooling circuit so no air bleeding was needed. It was set to 15C with an ambient of around 27C and it is happily holding that 15C temperature of the cooling water.Thank you for the information on the water circulation pump. I was wondering why it had a course green filter in it ! It sounds very quiet at teh moment but I will look into obtaining a spare shaft and impeller, or a new pump in case it is needed. I think these units run with either a special fluid or you can use a alcohol/water mix. I wonder whether the special cooling fluid contains something to reduce wear in the pump shaft ?I do not actually NEED the chiller but fancied owning a miniature chiller unit in case of future need. With our present heat wave in the UK I could make a cooled bed for the cats to rest onI have plenty of 12mm hose for such a project.Fraser

author: Gyro
author_rank: Super Contributor
timestamp: July 20, 2016, 06:19:44 pm
content: Hi Fraser,The Eheim pump impeller uses a carbon bush running on the ceramic shaft, so it just uses the water as a lubricant, nothing special (or available!) in the case of aquarium and pond use. Your mileage may vary considerably, our aquarium pump has done 25 years with no signs of wear. I suspect a bit of engine coolant might provide some additional lubrication (and toxicity), if compatible with the plastics.Chris

author: Fraser
author_rank: Super Contributor
timestamp: July 20, 2016, 06:39:27 pm
content: Hi Gyro,I read on the Perkins Elmer web site that the cooling fluid can be car coolant Glycol and water mix and this is needed for cooling temperatures below 0C for obvious reasons. That is what I will be using if using the unit for any length of time.Fraser

author: AndyC_772
author_rank: Super Contributor
timestamp: July 20, 2016, 07:19:49 pm
content: That sounds like an interesting piece of kit, and I have the perfect application for it.When my wife and I make beer, one of the last stages in the process is to cool it from boiling down to a temperature that won't kill the yeast.The quicker that happens, the less chance there is of airborne bacteria getting in, multiplying, and spoiling the beer, so we use a 'wort chiller' which is a copper coil through which cold water is passed. This doesn't work too well in summer, when the water supply isn't very cold, and it's quite wasteful of water.A small chiller like this would be ideal. If you don't find a use for it yourself, consider me interested. It'll be going to a good home for a very good cause indeed

author: SeanB
author_rank: Super Contributor
timestamp: July 20, 2016, 07:26:23 pm
content: Just remember if you use the glycol that it is very poisonous for cats to drink it, and it will grow a biofilm in a few years in the open tank. I currently run a cooling loop with plain DI water with a low concentration of KI dissolved in it. this keeps the water at least bioneutral, and works a lot better than the glycol, which bacteria use as food.

author: Fraser
author_rank: Super Contributor
timestamp: July 20, 2016, 08:07:08 pm
content: SeanB,Many thanks for the advice. I was not aware that Glycol can lead to bacterial growth. It is only needed for sub zero working so DI water is the way I will goAndyCYes this unit would be superb at beer coolingI ran the unit in the garden with a 2m hose and set it to various temperatures down to and including 2C. It cooled to that temperature with no trouble at all and I am very impressed with how quiet the unit is. Just like a standard fridge.I only just got the unit and honestly have no idea whether I want to keep it or not. If I were made a generous offer in order to benefit my hobby budget I may be persuaded to part with it now.I will add some pictures of my cooling test in a minuteFraser

author: Fraser
author_rank: Super Contributor
timestamp: July 20, 2016, 08:13:31 pm
content: Cooling test picturesAmbient temperature was around 24CMinimum set was 2C to avoid the possibility of ice formation in the tap water.Fraser

author: Fraser
author_rank: Super Contributor
timestamp: July 20, 2016, 08:25:59 pm
content: As already stated, the water pump is helpfully a COTS product that was easy to find on the internet.https://www.eheim.com/en_GB/products/technology/pumps/universal-1200The unit uses the EHEIM 1250 universal pump that provides an inlet and outlet pipe connection as standard. Spares are easily sourced so this was a decent choice by the chiller manufacturer.Manual attachedFraser