Ss Brewing Technologies Giveaway!

Home Brew Forums > Home Brewing Beer > DIY Projects > 5500W Element Control: To PID, or not to PID?
Reply
 
LinkBack Thread Tools
Old 07-06-2010, 08:44 PM   #1
lustrum
Feedback Score: 0 reviews
Recipes 
 
Join Date: May 2010
Location: Atlanta, Georgia
Posts: 45
Default 5500W Element Control: To PID, or not to PID?

Hey guys,

It seems like I've read a copious amount on the topic of controlling an electric kettle and HLT with a PID/SSR combination, yet I still have some questions. My goal is to control the kettles in a very simple way--meaning I would prefer to not use a thermowell or RTD to control the SSR-element, and I would only be controlling one element at a time.

I've read posts that state using a PID/SSR for "manual" mode is a waste of engineering, which makes sense to me, in some ways. For my purposes, anyway, it would seem to be overkill.

Here's my goal: control one 240v element at a time so that I can manually adjust the temperature of the wort or water in the kettle. Am I locked in with the PID/SSR combo?

Thanks

__________________
lustrum is offline
 
Reply With Quote Quick reply to this message
Old 07-06-2010, 08:50 PM   #2
Walker
I use secondaries. :p
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
Walker's Avatar
Recipes 
 
Join Date: Sep 2005
Location: Cary, NC
Posts: 11,236
Liked 86 Times on 77 Posts
Likes Given: 11

Default

If you really want temp control, then the PID is really the way to go. You could *probably* do it with a pulse width modulator, but it'll be a royal PITA.

Also, if you just want to boil, you can probably skip all control and just plug it in. I have a 5500W element in my BK and a pulse modulator to control it, but I brewed the last three batches with the PWM cranked up to 100% on the boil. I could have just plugged it in and let it roll.

__________________
Ground Fault Brewing Co.
Walker is offline
 
Reply With Quote Quick reply to this message
Old 07-06-2010, 09:07 PM   #3
passedpawn
Waste Allocation Load Lifter - Earth Class
HBT_MODERATOR.png
Feedback Score: 0 reviews
 
passedpawn's Avatar
Recipes 
 
Join Date: Apr 2009
Location: ☼ Clearwater, FL ☼
Posts: 18,896
Liked 3336 Times on 2065 Posts
Likes Given: 2835

Default

If you want to control temperature (as you say), then AUTO mode (not manual mode) is what you want. Yes, you should get a PID and a temp sensor of some kind.

__________________
Hey goomba I love how you dance the rumba
But take some advice paisano learn-a how to mambo
If you're gonna be a square you ain't-a gonna go anywhere.
passedpawn is offline
 
Reply With Quote Quick reply to this message
Old 07-06-2010, 09:15 PM   #4
brrman
Feedback Score: 0 reviews
Recipes 
 
Join Date: Oct 2006
Location: Indianapolis, IN, Indiana
Posts: 1,432
Liked 30 Times on 25 Posts
Likes Given: 18

Default

Use a PID with a K-type thermocouple on Auto mode for any temp control. It's easy and consistent every time once you have it dialed in.

But like Walker says - not really needed for a simple boil... Though I use a 2nd PID in manual mode in my system for the boil. I maintain a good rolling boil at 55-60% power with a 5500w element.

__________________
* My Bar Build
8-Paws Brewing Co.
On tap:
. SN Tumbler Clone
. Nierra Sevada
Secondary:
Primary:
. SN Tumbler Clone 10g
. Sycamore Oatmeal Porter 10g
. Nierra Sevada 10g
On Deck:
.
Kegged:
.

Being a perfectionist does not make one perfect.

Last edited by brrman; 07-06-2010 at 09:17 PM.
brrman is offline
 
Reply With Quote Quick reply to this message
Old 07-06-2010, 09:34 PM   #5
Brewmoor
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
Brewmoor's Avatar
Recipes 
 
Join Date: Aug 2009
Location: Colorado
Posts: 1,094
Liked 13 Times on 13 Posts
Likes Given: 13

Default

I would have to say the PWM is the way to go. As for ease of use there is no easier way. Just turn the dial.

Walker: What type of PWM are you using. With mine I can not put it past half way during boil or it will boil over. I am using a 5500w element. Most of the time it is set just between and 1/4 and 1/2 for maintaining a rigorous boil.

__________________

"What the mind can conceive and believe, the mind can achieve."

My build thread. Compact Single Tier!

Brewmoor is offline
 
Reply With Quote Quick reply to this message
Old 07-07-2010, 12:22 AM   #6
Walker
I use secondaries. :p
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
Walker's Avatar
Recipes 
 
Join Date: Sep 2005
Location: Cary, NC
Posts: 11,236
Liked 86 Times on 77 Posts
Likes Given: 11

Default

Quote:
Originally Posted by Brewmoor View Post
Walker: What type of PWM are you using. With mine I can not put it past half way during boil or it will boil over. I am using a 5500w element. Most of the time it is set just between and 1/4 and 1/2 for maintaining a rigorous boil.
Mine is a DIY PWM. One 555 timer IC, one potentiometer, and a couple of capacitors.

My kettle is not well insulated, so I think that's why I can run it at full blast and not boil over during the main part of the boil (a boil over is EASY at the start before the hot break).

At 100% on with the 5500W element, the boil is pretty violent..... makes the whole brew-stand wobble back and forth.
__________________
Ground Fault Brewing Co.
Walker is offline
 
Reply With Quote Quick reply to this message
Old 07-07-2010, 01:53 PM   #7
lustrum
Feedback Score: 0 reviews
Recipes 
 
Join Date: May 2010
Location: Atlanta, Georgia
Posts: 45
Default

I hadn't thought of using a PWM. I guess if I was going to build one, though, I may as well build a PID/SSR controller and just drop the thermocouple over the the side of the kettle to measure temps, so I can keep it portable.

Any recommendations for a basic PID/SSR combo to control one 5500W element?

Not to hijack my own thread, but I was wondering about the virtues of putting a GFCI breaker in the control box vs at the breaker box. Anyone done this?

__________________
lustrum is offline
 
Reply With Quote Quick reply to this message
Old 07-07-2010, 02:17 PM   #8
Brewmoor
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
Brewmoor's Avatar
Recipes 
 
Join Date: Aug 2009
Location: Colorado
Posts: 1,094
Liked 13 Times on 13 Posts
Likes Given: 13

Default

I used this page to build my PWM. It is a very simple circuit. It too requires an SSR. http://home.highertech.net/~cdp/boilnew/boilnew.htm

I am not sure I would attempt to build a PID. It would be better to just buy one. I have been happy with the one I got from Auber Instruments. http://www.auberins.com/index.php?main_page=index&cPath=1&zenid=9fbff14ed9 10c984a29f2231ebd9a7b7
Though I dont really use it as a PID. I end up just putting up to 200 and waiting for it to get to the temp I need. I have found I don't really need the "Hold" temp feature since I am mostly batch sparging.

If you can still find them. There is a GFI cord that I got on Ebay. It seemed to be the best option for me. Since I rent it was nice to buy a cheap breaker for the panel and have my GFI universal. It is built into the cord and has a standard 240v plug on the end.

__________________

"What the mind can conceive and believe, the mind can achieve."

My build thread. Compact Single Tier!

Brewmoor is offline
 
Reply With Quote Quick reply to this message
Old 07-07-2010, 02:39 PM   #9
RandomSF
Feedback Score: 0 reviews
Recipes 
 
Join Date: Nov 2009
Location: Wisconsin, USA
Posts: 77
Default

Just curious, how would a temperature controller work to control the vigor of the boil. E.g., say your wort boils at 50% On in Manual, and boils vigorously at 70% On. For either percentage, the temperature is the same, only how hard it's boiling changes. How would a temperature controller help here?

__________________
RandomSF is offline
 
Reply With Quote Quick reply to this message
Old 07-07-2010, 02:45 PM   #10
Walker
I use secondaries. :p
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
Walker's Avatar
Recipes 
 
Join Date: Sep 2005
Location: Cary, NC
Posts: 11,236
Liked 86 Times on 77 Posts
Likes Given: 11

Default

Quote:
Originally Posted by RandomSF View Post
Just curious, how would a temperature controller work to control the vigor of the boil. E.g., say your wort boils at 50% On in Manual, and boils vigorously at 70% On. For either percentage, the temperature is the same, only how hard it's boiling changes. How would a temperature controller help here?
It's all about pulse width modulation.

What you are doing is telling the controller that you want the element to be on for <whatever>% of the time. The PID will turn the element on and off based on your programming.... and it does not use the input from the temp probe when doing so.

When the element is on, it is 100% on. When it is off, it is 100% off.

But, by programming it to do something like "turn on for 1 second, then turn off for a half second", you are effectively getting 66% power from your element.

A PID is kind of overkill for this because all of the smarts of the PID and the temp input are not used. You can use a simple pulse width modulator circuit to get this behavior for a fraction of the price of a PID.

BUT... If you need a PID part of the time (mash) and then a PWM the other part of the time (boil), and you don't need to do these things at the same time, a single Auber PID with "manual mode" support is perfect for the job. You just switch the mode of operation when you need the PWM behavior.

EDIT: even in manual mode, the PID needs a temp probe connected to it, but it doesn't actually USE the input from the probe. You can leave the probe dangling in the air if you want.
__________________
Ground Fault Brewing Co.
Walker is offline
 
Reply With Quote Quick reply to this message
Reply



Quick Reply
Message:
Options
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
5500W RIPP ultra-low density element in Canada? kal DIY Projects 7 03-12-2012 12:16 PM
5500W Heating Element, how do I install it? The Pol DIY Projects 15 06-18-2010 03:33 AM
Using 2 simmerstats to control 4500W/5500W element gregdech DIY Projects 10 04-15-2010 03:46 PM
Will this do what I need for a heating element control? RedIrocZ-28 DIY Projects 9 12-28-2009 04:33 PM
Sold - NEW 5500w RIPP ULWD element & SS lock nut cyberbackpacker For Sale 2 12-11-2009 09:42 PM