picked one of these up on ebay*:http://tinyurl.com/36jrm5*similar to Watlow series 360 temp controller from what i can tell. anyone used one of these? i'm thinking of using it for roaster temp control w/ a probe in the bean mass, but can't figure out which terminals to hook the SSR to (only one shown, as you can see in the 2nd pic in the listing). would the one designated as "Solid State Fusac" be SSR control + or -? AC or DC? would the other SSR control voltage terminal connect to the "N.O. Contact" terminal? i can't find any manuals online as this is apparently a much older model than Watlow currently offers.
We had lots of Love, Omega and Watlow controllers at CSMRI, and from 1977 I was their instrument tech. The Research Institute always got stuff from CSM, and there weren't always manuals and schematics [Usually none] with which to set up the projects. I could always get manuals by calling the manufacturer or a distributor On 6/11/07, stereoplegic wrote: <Snip> -- "When the theme hits the bass, I dance the Jig!" - -Virgil Fox at the Mighty Wichita (ex- NYC Paramount) WurliTzer- 1976
Oh, Hell! It's calibrated for a type J thermocouple. The couple is Iron/ Constantan. The Iron wire will corrode in a hurry, and the corrosion is Gauronteed to give an early false junction. "...similar to Watlow series 360 temp controller from what i can tell." Of course, there is never any BS from eBay sellers- the caveat is: "...we have no knowledge..." I do. If it's a decent controller, you can calibrate the zero and span. Watlows could. You'd just need a milivolt potentiometer with a good standar= d cell in it, or an ice water bath and a boiling water bath. But that would only cover half the range of interest unless you built a thermopile with tw= o or more junctions series-connected. Then you have to read the chart. If you have 5 junctions in series at 212= °F, you just have 5X the 212°F emf, not the 1060°F emf. It's non-linear- fo= llow the emf/ temperature chart. Also, the type J thermocouple is near its limit at the 1000°F range- mayb= e due to the nonlinearity of the Iron wire. A bare J thermocouple won't last long around 450°, but it would be much more rugged in a 1/8in stainless steel or Inconel sheath with a grounded junction. Whatever you do, don't kid yourself- you can put the probe anywhere you want. Even "a probe in the bean mass" is going to tell you the temperature of the measuring junction- nothing more. Any probe well anchored in the bean mass will just give you false readings. If the probe moves at all, you will get variable false readings, statements to the contrary by junior Science Fiction writers notwithstanding. The controller is only a part of the temperature control system. A type J thermocouple is almost the worst case sensor. Cheers -RayO, aka Opa! Got Grinder?
the type J thermocouple i'll be using has a stainless steel sheath. i would have gone for a type T model i saw listed around the same time, but sheathed T thermocouples seem to be much harder to find. the "series 360" reference was my own, not the seller's. "Watlow j-trol" and "Watlow 32-06-11 (the model #)" turned up nada on google. their website only seems to have manuals, etc. for current models. raymanowen wrote: <Snip>
I love your phrase: the junior Science Fiction writers on this list Type J thermocouples corrode in water so don't use them to measure your brew temps. But by all means, they are suitable and accurate for measuring bean temps. That is what I use for the bean temps in my CCR. See www.computercontrolledroaster.com I have inspected my probes many many times and I assure you that the high temperatures and the oil deposits are more than adequate to protect the open junction. I have precision calibration equipment and I can confirm repeatable accuracy of 0.3 deg F of my bean temperature measurements. Some of my probes have had nearly 1000 roasts without any degredation. I again stress (very important) that I use double kapton covered thermocouple wire. This does not shed, melt, outgas, or produce any toxic materials in food at up to 500 deg F continuously. Jeffrey Pawlan
Try Tech Support Talk to an engineer at 800-884-4967. (M-F 8:30-5:30 ET) The link was on the Watlow site. Cheers -RayO, aka Opa! On 6/12/07, stereoplegic wrote: <Snip> -- "When the theme hits the bass, I dance the Jig!" - -Virgil Fox at the Might= y Wichita (ex- NYC Paramount) WurliTzer- 1976
I found this: *360A-3603-3000* Watlow Series 360 Temperature Controller - 1/4 DIN, On/Off control, Type K input 0 to 2500F, integral setpot dial control, 10 amp relay output, 120/240VAC line voltage. One new unit available. $300.00 *$99.00*at: On 6/12/07, raymanowen wrote: <Snip> s <Snip> w <Snip> - <Snip> s <Snip> -- "When the theme hits the bass, I dance the Jig!" - -Virgil Fox at the Might= y Wichita (ex- NYC Paramount) WurliTzer- 1976
thanks RayO! raymanowen wrote: <Snip>
yeah, i saw that, that's one of the sites that made me think it's similar to the Series 360. thanks again for all your help researching this. raymanowen wrote: <Snip>
Bottom line: "Some of my probes have had nearly 1000 roasts without any degredation." I would never argue with success- If it ain't Busted, Don't Touch! ! ! But= , I ask, would you know that the performance of the junction had degraded, an= d would you be satisfied with a sensor that was only reliable for several hundred or a few thousand cycles? Most common temperature sensors are more reliable than a few thousand cycles- like the thermostat for your furnace, automobile engine, etc. As for burning up thermocouple junctions, I'm sensitive to that because we often operated 14ga type K junctions in alumina wells above 2000°F. Or a 3000°F glass furnace with Platinum- Rhodium thermocouples in tungsten coa= ted alumina wells. Some people think the sheathed thermocouples are rare- Not so. Anything is available for a price. For coffee roasting, oxidation and reduction are possible, maybe not so rapid at the temperatures involved. What would stop the use of a s/s sheathed type K grounded junction? Cheers -RayO, aka Opa! "I'm not a failure. I've just found 10,000 ways that won't work-" - -Thomas A. Edison
finally got my type J thermocouple (w/ stainless probe sheath) yesterday. after wiring the power and thermocouple, tried adjusting the knob to above room temp. the red LED in the middle of the knob lit up, so i tried the "SSR" and "N.O. contact" terminals w/ my multimeter w/ the knob at 200F. no voltage shown, despite the lit LED. so i tried the "ISO-drive +" and "ISO-drive -" terminals, and again moved the knob up to 200F. 15.4V. Voila. turned the knob below room temp, 0V. turned it back up, 15.4V. hooked up the SSR (3-32VDC control) to the "ISO-Drive" terminals, and turned the knob back above room temp. both the J-trol's and the SSR's LEDs lit up. turned below room temp, both went out. above, both lit up again. long story short, it works, just not on the terminals i thought it would use. now, lets see if i can get the rest of my rig hooked up in time for the homeroasters.org contest. stereoplegic wrote: <Snip>