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View Full Version : Temperature controller which operates down to -100C/-150F







DaBit
01-10-2003, 04:10 PM
For my cascade I am looking for a temperature controller which allows sensor temperatures down to -100C / -150F.

Ideally it would have the following features:
- Temperature range -100C .. +50C (-150F .. +120F) or better.
- Single 220V / 15W capable relay output or better
- Setup for compressor cut-in and hysteresis
- Supply 12 VAC/VDC, 24 VAC/VDC or 220 VAC
- Short-cycle protection would be a nice feature.
- Pt100 sensor inputs are preferred.

I am quite fond of the Eliwell controllers (I'm using the EWPC-901 in the high stage), but I haven't found any which goes below -80C.

Of course, I can design/build one myself, but it wouldn't be better than off-the-shelf stuff. It only takes a lot of time.

Which controller would you recommend?

Andy
01-10-2003, 09:50 PM
Hi Dabit:)
control temperature is very low, most off the shelf controllers are designed for much higher ranges.
What about a PLC such as the Mitsibushi Alpha with an analogue input card, using a 4-wire PT 100 probe (4-20ma). All the parameters you can program yourself.
Regards. Andy.

DaBit
02-10-2003, 08:51 AM
Now that would be a totally different price (and size) class than a simple Eliwell-like temperature controller with extended temperature range. I am afraid that PLC + active sensor + analog input card costs more than the entire cascade system.

Peter_1
26-10-2003, 09:42 AM
Try at www.jumo.de

The rest of the explantion is in Dutch because the sender was from the Netherlands and it is mutch easier for me to explain the rest in Dutch.

Zij hebben een compleet gamma (D- tron en volgende) , ideaal geschikt voor uw toepassing.
U kunt zelfs een type krijgen waarbij u een bepaalde 'afkoelcurve' kunt ingeven met zekere 'HOLD ' niveaus (tijd en temperatuur) (bijvoorbeeld voor verouderingskasten)
Wij hebben reeds een aantal keer deze toestellen gebruikt.
Ze zijn wel niet zo goedkoop, vooral als je het dan vergelijkt met Eliwell en Dixell. (eliwell +/- 50 €, Jumo +/- 600 €)

Ik ben wel geïnteresseerd in hoe u dit verder koeltechnisch zult oplossen. Hermetische machines, semi- hermetische, gebruikte koelgassen, toepassing...
Ik heb in het verleden ook een aantal toepassingen gehad en het blijven toepassingen waar niet velen zich durven aan wagen.

DaBit
27-10-2003, 11:43 AM
Originally posted by Daliti
Try at www.jumo.de

Nice controllers, but indeed expensive. They are a good alternative for the Simpson controllers.


The rest of the explantion is in Dutch because the sender was from the Netherlands and it is mutch easier for me to explain the rest in Dutch.

I will reply in English so the rest of us can continue following the thread.


U kunt zelfs een type krijgen waarbij u een bepaalde 'afkoelcurve' kunt ingeven met zekere 'HOLD ' niveaus (tijd en temperatuur)

The ability to enter a 'cooling curve' is not strictly necessary, but it might be a nice feature to cope with mechanical stress induced due to rapid cooldown. Currently only the copper mass reduces cooldown speed.



Ik ben wel geïnteresseerd in hoe u dit verder koeltechnisch zult oplossen. Hermetische machines, semi- hermetische, gebruikte koelgassen, toepassing...

The application is to cool a PC's microprocessor. And since I am a hobbyist and not a professional, I have to work with what I can get. In reality this means scavenged hermetic compressors, homebuilt oil separator, refrigerant which is available at the ACR engineers who help me with handing the actual refrigerant (I don't have the required STEK license), etc.
The only thing I don't want to save a few cents on are safety related.

Currently I am using an R22 A/C compressor in the high stage, which is running with R507 (of course I changed the oil to POE), and a LBP R134a compressor in the low stage. The low stage is currently running R410A since this is safer to experiment with. Later on I will use ethane as the low stage refrigerant. R23 won't cut it due to skyrocketing discharge temperatures. R508b would have been the preferred refrigerant, but it is very expensive (about $100/kg)

The progress of the cascade is described here (http://www.icecoldcomputing.com/text/show_page.php?id=68) on my personal website: http://www.icecoldcomputing.com