Cheap temp controllers

[Richard Jack]

Dual channel temp controllers, free shipping going on ebay:

http://cgi.ebay.com/Mini-Digital-Temperature-Controller-Thermostat-...

The seller seems to have a lot of them, going for around 25-30 USD with free worldwide shipping. They look just like the ones from craftbrewer, but a much lower price + free shipping. Think I might grab a few :)

[hayden]

Thanks for the reply

 

I've found the following sensor for 27nzd, will use that for the HLT, and use the supplied one for something else, maybe fermentor, or fridge.

will they handle a 2000 watt element alright, or is it better to run it via a relay?

http://newzealand.rs-online.com/web/0461159.html

[Paul Wicksteed - another1]

I would add a relay for the HLT, the controllers handle 10amps so it would be a good idea to add a relay for that extra protection, or a circuit breaker

[Paul Wicksteed - another1]

Would pull 8.4amps so maybe just a circuit breaker would be okay

[hayden]

Awesome, thanks for that...

 

Was wondering about the longevity of the temp controller. Guess it will come down to the cost, considering the controller only cost 33nzd.

 

 

 

 

 

 

[Paul Wicksteed - another1]

Don't know about that, mine are constructed in a well sealed box, to eliminate the chance of corrosion in a brewing environment. So they should last for a while.

[hayden]

Yeh, was more to do with the amps nearing the upper limits recommended. Thought the contacts might fry. Will go with the relay idea, should get many years that way. Great units for the price

[mattd2]

You shouldn't have to worry about the amps getting up to (as long as not over) the limit. They relays are usually rated for 100,000 operations (mech I think but don't have any specific info on me) at their rated load - 10 Amps / 250 VAC in this case. You'll have to see how quickly the element turns on and off for a given differential value but the minimum compressor delay is 1 minute so, if you are controlling the MLT from heating the strike water to end of the sparge lets assume it will be cycling for 2 hours (I think this is generous for a 1 hour mash given while the water is heating up it will not be cycling). With the comp delay set at 1 minute and it actually cycling this fast you'l have 120 operations per brewday so you should see (100,000/120 =) around 800+ brewdays before it goes. Thats 16 years brewing 1 batch a week.

Also they use pretty standard parts (probably the same relay you would buy for your external one) so if/when it did go you could take the cover off, desolder the old relay, and replace with a brand new (standard) one.

Also this way you might be able to uprate your unit to take more than 2400 W but you'd have to check if the connection to the unit could take the load you want to put on them.

[Richard Jack]

I'm not using them on my HLT (at the moment anyway), just a set of fridges. If I wanted to use one in an HLT I would use a bit of copper pipe and make a poor man's thermowell. I'm looking at cheapy PID controllers for HLT at the moment.

[Sam Anderson]

Thanks for the info on the temp controllers!  What are the probes like? Or, can any one recommend some "probes" to hook up to them, that go into the fermeter / hlt to do the temp measurement?

 

Cheers

 

[Paul Wicksteed - another1]

I just use the default probes that come with the STC-1000, and put them into a thermowell. I have looked at all of the other probes available, but to ensure no contamination they need to go into a thermowell anyway, so might as well go with the default.

 

You can by SS304 probes with 1/2" NPT thread, that can replace the thermowell, and are therefore a fixed feature of the fermentor / HLT, but then you need plugs to contact and disconnect the probe from the controllers when moving it all around etc.

 

Another option is to place the probe in a plastic cup of water, in the "environmentally controlled fermentation chamber" (fridge) along with the fermentor, then you actually get a reading of the water temp, which should be the same as the wort. Without any probing into the wort at all.

 

[Sam Anderson]

Hey cheers Paul!

thats sounds good. you say SS304 probes - i think this sounds the best idea, with the disconnecting contacts. Would you have any idea where i can pick these up from ? ebay?

 

The cup of water sounds a little distorted to my mind, for fermenting?, as the mass of the fermentor would hold longer? than the cup? (all questions as ive not had experience with it)

 

Cheers again

[Paul Wicksteed - another1]

Hi Sam, have a look at this www.craftbrewer.com.au but it is for heating or cooling only, i.e. not like the STC-1000 that has 2 outputs one for heat and one for cooling. You still have to wire it all up etc, but you would be doing that for your setup anyway. Make sure you pick the right Amp though, or run it through another relay. eBay will also have heaps of stuff, as with aliexpress

 

Yeah I was surprised at the water in a glass solution, and tried it for one brew and it seemed to run alright.