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01-10-2003, 04:10 PM #1
Temperature controller which operates down to -100C/-150F
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?
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01-10-2003, 09:50 PM #2
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.
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02-10-2003, 08:51 AM #3
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.
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26-10-2003, 08:42 AM #4
Temperature controller
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.
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27-10-2003, 10:43 AM #5
Re: Temperature controller
Originally posted by Daliti
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.
U kunt zelfs een type krijgen waarbij u een bepaalde 'afkoelcurve' kunt ingeven met zekere 'HOLD ' niveaus (tijd en temperatuur)
Ik ben wel geïnteresseerd in hoe u dit verder koeltechnisch zult oplossen. Hermetische machines, semi- hermetische, gebruikte koelgassen, toepassing...
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 on my personal website: http://www.icecoldcomputing.com
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