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jengel
Joined: 20 Dec 2011 Posts: 14
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Link Posted: Fri Dec 23, 2011 9:07 pm Post subject: Alternate relays and PIDs |
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I'm in the process of building an electric brewery based on this website. I've been making a variety of substitutions to some of the parts in order to simplify and save some money. It remains to be seen if these alternate parts perform as well as the fine parts suggested by the build instructions but I thought I would share some of what I have found in case it is of use to other cheapskates out there. Compared to the $2k in stainless fittings and pots, saving $200 on relays and PIDs seems a little silly but I can't help myself.
I've found the relay below from Magnecraft (Schneider) to be a cheaper ($8) replacement:
Part no: W92S7A22D-120
http://www.serelays.com/products.php?t=92
http://www.zorotools.com/g/Enclosed%20Power%20Relays%20Magnecraft/00062830/
Regarding the PIDs, if you are OK with a larger housing (which may not fit in the specified cabinet), comfortable modifying a PID to convert from relay to SSR output by bypassing an internal relay, and you are OK with C rather than F temp readings, then you can get the PID below for about $16 when you buy 3. Despite some of the discussion regarding this unit I have verified that it will accept RTD input and generates a 12VDC output signal when the relay is bypassed. I have not been able to get it to switch from C to F however. Time to embrace the metric system!
http://www.dealextreme.com/p/digital-temperature-controller-900166334
Good luck to everyone! Thanks Kal and the rest for sharing such a wonderful resource.
-Jon
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kal Forum Administrator
Joined: 12 Dec 2010 Posts: 11123 Location: Ottawa, Canada
Drinking: Pub Ale, Electric Creamsicle, Mild, Pliny the Younger, Belgian Dark Strong, Weizen, Russian Imperial Stout, Black Butte Porter
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Link Posted: Fri Dec 23, 2011 10:05 pm Post subject: Re: Alternate relays and PIDs |
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jengel wrote: | Regarding the PIDs, if you are OK with a larger housing (which may not fit in the specified cabinet), comfortable modifying a PID to convert from relay to SSR output by bypassing an internal relay, and you are OK with C rather than F temp readings, then you can get the PID below for about $16 when you buy 3. Despite some of the discussion regarding this unit I have verified that it will accept RTD input and generates a 12VDC output signal when the relay is bypassed. I have not been able to get it to switch from C to F however. Time to embrace the metric system! |
Even though you may be able to hack the PID to have it control an SSR instead of a relay, won't the cycle times be way too long? Most PIDs that are meant for relays have cycle times of 20-40 seconds. For example, with a cycle time of 20 seconds, if you set the boil PID to manual mode at 50% the element will be on for 10 seconds then off for 10 seconds. That's way too long and result in a boil that's overly vigorous and then completely dead (no rolling at all) followed again by an overly vigorous boil, then deal, etc.
PIDs meant for SSRs typically have a cycle time of 2 seconds.
Long story short: You can't use a PID meant for relay control in a boil kettle. It just wouldn't get you the boil you need.
Have you used this PID yourself yet? You emailed me about it around 2 days ago when you said you were still sourcing components.
Kal
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My basement/bar/brewery build 2.0
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jengel
Joined: 20 Dec 2011 Posts: 14
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Link Posted: Fri Dec 23, 2011 10:26 pm Post subject: |
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I have tested everything I said I tested above although I have not boiled any water with this controller yet. Your concerns may be validated once the system is assembled. However, the proportional cycle time while set to a default of 20 seconds for the relay version I linked to is adjustable from 1 to 100 seconds. Based on playing with the menus and listening to the relays click, I am confident that the cycle time can be reduced to a value more suited for an SSR. I will update once I have boiled some water, I'm waiting on a few more parts and the nerve to punch a heater hole in my kettle.
Thanks for your help.
-Jon
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kal Forum Administrator
Joined: 12 Dec 2010 Posts: 11123 Location: Ottawa, Canada
Drinking: Pub Ale, Electric Creamsicle, Mild, Pliny the Younger, Belgian Dark Strong, Weizen, Russian Imperial Stout, Black Butte Porter
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Link Posted: Fri Dec 23, 2011 10:45 pm Post subject: |
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If you can get the cycle time down to 2 seconds then that would be good.
Does it have auto tuning available?
Kal
_________________ Our new shop with over 150 new products: shop.TheElectricBrewery.com
We ship worldwide and support our products and customers for life.
Purchasing through our affiliate links helps support our site at no extra cost to you. We thank you!
My basement/bar/brewery build 2.0
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crush
Joined: 28 Dec 2010 Posts: 706 Location: Telemark, Norway
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Link Posted: Sun Dec 25, 2011 3:25 pm Post subject: |
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I think the relays are a good find - $8 compared to $45 is a good saving - 45-8 = 37 x 3 = $111 saved and I prefer the sealed units. My relays have been a bit finicky and had to bend one of the sides of the armature to get it to make full contact, and the screws do come loose after a while, so the push on connectors would be a welcome replacement.
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jengel
Joined: 20 Dec 2011 Posts: 14
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Link Posted: Thu Dec 29, 2011 3:34 pm Post subject: |
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@Crush - I haven't tested the relays yet on the 5500W heating element, although the numbers on paper look like a good match. The type of terminals (spade) are a little tougher to work with when sending multiple wires in/out though.
@Kal - The PIDs do have an auto tune mode according to the manual although I have yet to try it on a pot of water. Just got back from a trip and hope to get the boil pot wired up to test sometime soon.
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crush
Joined: 28 Dec 2010 Posts: 706 Location: Telemark, Norway
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Link Posted: Fri Dec 30, 2011 9:05 am Post subject: |
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I wouldn't try squeezing multiple wires into a push on terminal, especially the larger gauges. You can get "piggy back" terminals which allow multiple connections to be stacked. (They have both a male and female connection.)
_________________ ...just one more.
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jengel
Joined: 20 Dec 2011 Posts: 14
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Link Posted: Fri Dec 30, 2011 2:03 pm Post subject: |
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@crush : I agree. I am planning on drilling out the hole in the spade to accept a 6-32 screw and make my own "binding post" for multiple ring terminals.
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jengel
Joined: 20 Dec 2011 Posts: 14
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Link Posted: Tue Feb 14, 2012 6:56 pm Post subject: |
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So after building everything and the first brew session, I can say that the PIDs work fine but do not have a manual mode. The PIDs do not display in degrees F, regardless of what the manual says. Converting the PIDs from relay to SSR output took about 5 minutes apiece.
For boiling, I was able to set the PID target temp to around 98.7 C and maintain a steady rolling boil, with the SSR output kicking on at about 50% duty cycle. So, manual mode wasn't needed in my case.
For the relays, they worked great. The spade terminals required me to do one 10 gauge wire splice and to thread in a smaller wire for the key switch into one connection but otherwise worked fine. I decided not to drill out the spades to make binding posts because I felt the spades would become too flimsy and would bend under all the 10 gauge wire manipulation.
Total control panel cost was around $225 + $98 for a 30A 240V GFCI breaker (http://livewiresupply.com/)
3x relays = $24 (http://www.zorotools.com/)
1x keyswitch = $2 (Axman surplus)
3x XLR socket = $10 (eBay)
2x locking 240VAC socket = $40 (home depot)
1x dryer cord = $22 (home depot)
1x 3/4" cable clamp = $1 (home depot)
4x box of spade lugs = $10 (home depot)
3x PIDs = $50 (www.dealextreme.com)
3x toggle switches = $6 (Axman surplus)
2x 240V lamps = $2 (Axman surplus)
2x SSR heatsink = $19 (www.lightobject.com)
2x SSR = $37 (www.lightobject.com)
Misc wire, outlets, and wood = free
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kal Forum Administrator
Joined: 12 Dec 2010 Posts: 11123 Location: Ottawa, Canada
Drinking: Pub Ale, Electric Creamsicle, Mild, Pliny the Younger, Belgian Dark Strong, Weizen, Russian Imperial Stout, Black Butte Porter
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jengel
Joined: 20 Dec 2011 Posts: 14
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kal Forum Administrator
Joined: 12 Dec 2010 Posts: 11123 Location: Ottawa, Canada
Drinking: Pub Ale, Electric Creamsicle, Mild, Pliny the Younger, Belgian Dark Strong, Weizen, Russian Imperial Stout, Black Butte Porter
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Link Posted: Tue Feb 14, 2012 9:35 pm Post subject: |
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Oops! You're right. So many builds... I got confused that that was yours.
Kal
_________________ Our new shop with over 150 new products: shop.TheElectricBrewery.com
We ship worldwide and support our products and customers for life.
Purchasing through our affiliate links helps support our site at no extra cost to you. We thank you!
My basement/bar/brewery build 2.0
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tcw126
Joined: 25 Oct 2011 Posts: 4
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Link Posted: Fri Mar 02, 2012 9:23 pm Post subject: PID in "Automatic" mode |
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Jengel,
Like you, I too purchased PID's that don't have Manual Mode. I purchased the Chinese Mypin TA4-SNR which have PID fuzzy & on/off control. There in my panel and I'm close to powering it up and boiling some water. I was concerned to and delighted to hear that you're able to get a rolling boil without boilover. My PID does show degrees F so I see that you set yours at 209-210F with 50% duty cycle. I'm going to try mine at that and hopefully I get similar results.
I'm guessing you have a few batches under your belt by now. How are the PID's working with the boil kettle? Are your temp & duty cycle settings still producing a nice boil?
Thanks,
Tom
jengel wrote: | So after building everything and the first brew session, I can say that the PIDs work fine but do not have a manual mode. The PIDs do not display in degrees F, regardless of what the manual says. Converting the PIDs from relay to SSR output took about 5 minutes apiece.
For boiling, I was able to set the PID target temp to around 98.7 C and maintain a steady rolling boil, with the SSR output kicking on at about 50% duty cycle. So, manual mode wasn't needed in my case.
For the relays, they worked great. The spade terminals required me to do one 10 gauge wire splice and to thread in a smaller wire for the key switch into one connection but otherwise worked fine. I decided not to drill out the spades to make binding posts because I felt the spades would become too flimsy and would bend under all the 10 gauge wire manipulation.
Total control panel cost was around $225 + $98 for a 30A 240V GFCI breaker (http://livewiresupply.com/)
3x relays = $24 (http://www.zorotools.com/)
1x keyswitch = $2 (Axman surplus)
3x XLR socket = $10 (eBay)
2x locking 240VAC socket = $40 (home depot)
1x dryer cord = $22 (home depot)
1x 3/4" cable clamp = $1 (home depot)
4x box of spade lugs = $10 (home depot)
3x PIDs = $50 (www.dealextreme.com)
3x toggle switches = $6 (Axman surplus)
2x 240V lamps = $2 (Axman surplus)
2x SSR heatsink = $19 (www.lightobject.com)
2x SSR = $37 (www.lightobject.com)
Misc wire, outlets, and wood = free |
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jengel
Joined: 20 Dec 2011 Posts: 14
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Link Posted: Thu Jul 19, 2012 1:26 am Post subject: |
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@TCW126-
I've got a bunch of batches under my belt with the system. Works great. I was able to get a good rolling but not too rolling boil with the PID by setting the cycle time to minimum which was 2 seconds and by tweaking the setpoint so that it was essentially firing the SSR at 50-60% duty cycle.
That was then, the situation now is that we had a little mishap with the PID and RTD on the boil kettle (BK) that essentially nullified all the above. Not sure what happened as I was not present, but a less than trained individual was operating the system and as near as I can tell was running the BK without the BK heater element plugged in. Something caused the RTD to get fried, as in open circuited by what I can only surmise was some kind of over current. Perhaps a flyback situation? The result was that the only way to finish the batch was to run the BK wide open at 100% duty cycle. Wow, talk about a steam room. Long story short, I ended up ditching the PID and RTD all together and just built a simple microcontroller with potentiometer to tune duty cycle manually for the BK SSR. So the new procedure is to fire up the BK with the duty cycle at 100% and dial it back to 50% when boiling. Not as fool proof but it has worked well for a few batches. If inattention is anticipated, I just run the BK at 60% at the get-go to prevent a boil over at the cost of increased time to boil.
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