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Finished BCS control panel

Posted: Mon Apr 05, 2010 7:17 am
by Budzu
I just finished this yesterday. Just a few more parts outside the panel left for full system functionality! Yes there's a couple holes left that I must seal up with some silicone.
Power routes through a 63a disconnect. Power for elements goes through 2 30a breakers, then 2 40a contactors, and 2 40a SSR's. Power for the contactor coils, 2 pumps, and BCS comes from the 10a breaker. All this is fed from my 100a subpanel right next to this box that I recently installed in this 10'x20' outbuilding. It houses a 60a gfci and 2 20a breakers for my fridges and lighting etc. It is fed from my main panel in my house from a normal 100a breaker, from which I buried 70 feet of 2 gauge 4 wire aluminum.

The BCS runs great! Thank you ECC for a stellar product. I now have to calibrate temp probes... using thermistors from Derrin at brewershardware.com and they read 224 at the boil and about 10F over in mash range. I gathered some temp samples and resistances and tried the calculator listed on this site, and the B value that the calc gives me will not take. Any suggestions?

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Re: Finished BCS control panel

Posted: Mon Apr 05, 2010 7:50 am
by ECC
Nice panel! Great work, I'm a big fan of wiring duct. What are the dimensions of your enclosure?

What are the exact ABC values that you are trying to program? The BCS only recognizes a certain precision (10 decimal places I think), so it might be truncating your values. I believe Derrin has a set of coefficients that he makes available for his probes.

Re: Finished BCS control panel

Posted: Mon Apr 05, 2010 8:27 am
by gbrewer
Very cool. Nice work!

Re: Finished BCS control panel

Posted: Mon Apr 05, 2010 11:52 am
by Budzu
ECC wrote:Nice panel! Great work, I'm a big fan of wiring duct. What are the dimensions of your enclosure?

What are the exact ABC values that you are trying to program? The BCS only recognizes a certain precision (10 decimal places I think), so it might be truncating your values. I believe Derrin has a set of coefficients that he makes available for his probes.
The enclosure is Hoffman 16"x14", I think its 6" deep.

As for the calibration, here are the resistances I recorded and their coinciding temps read with a calibrated therm:

37.2F (calibrated therm) - 26837.5 (bcs resistance at this value) (BCS registered 35.6F for this resistance)
112F - 4928.5 (110.2F)
180F - 1156.3 (190F)

In the low temps its reading low, at high temps its quite high.
With the calculator and default model number, I got:
A=0.0017479867
B=1.2114947e-4
C=6.02851e-7

The BCS didn't like the B value and scooted my decimal place to the left by like 4 digits and chopped of the last digits so I ended up with 0.001211494.

Re: Finished BCS control panel

Posted: Mon Apr 05, 2010 11:58 am
by Budzu
ok.. I found this on derrin's site:
You will need to enter the following coefficients into the BCS-460 setup panel to get them to read properly:

A= 0.001137155
B= 2.3259496e-4
C= 9.540003e-8
I'll try these out this afternoon or evening. Thanks guys for the nice comments :)

Re: Finished BCS control panel

Posted: Mon Apr 05, 2010 12:05 pm
by ECC
Yeah, that's normal. Its the same number, just a different representation. The BCS isn't able to store the whole number, so you lost the 7 on the end. This is well within the accuracy of the device.