Simple SSVR-controlled e-BIAB rig

[truckmann]

If you want to save money the Still Dragon kit is about the cheapest way to get most of what you need. http://stilldragon.com/index.php/diy-controller-kit.html

As for the contactor if you find a switch that can handle the amps you intend to run at you don't necessarily need it. It's usually cheaper to buy a contactor and a cheap switch than to just a switch that can handle the current though. This contactor is only $12. http://www.amazon.com/dp/B004Z0RLR6/?tag=skimlinks_replacement-20

You could get by with a 30 amp switch safely enough which are easier to find reasonably priced than a 40 amp, but it doesn't cost much extra to use a contactor and cheaper switch to step up to 40 amp just for some extra safety factor.

You could also run the Still Dragon box with no switch at all where you'd just have to unplug it to remove power. Not how I prefer to do things but I'm sure many people do that.

Here's the controller I built to work with an external temp controller I have.

 

[tennesseean_87]

If you want to save money the Still Dragon kit is about the cheapest way to get most of what you need. http://stilldragon.com/index.php/diy-controller-kit.html

As for the contactor if you find a switch that can handle the amps you intend to run at you don't necessarily need it. It's usually cheaper to buy a contactor and a cheap switch than to just a switch that can handle the current though. This contactor is only $12. http://www.amazon.com/dp/B004Z0RLR6/?tag=skimlinks_replacement-20

You could get by with a 30 amp switch safely enough which are easier to find reasonably priced than a 40 amp, but it doesn't cost much extra to use a contactor and cheaper switch to step up to 40 amp just for some extra safety factor.

You could also run the Still Dragon box with no switch at all where you'd just have to unplug it to remove power. Not how I prefer to do things but I'm sure many people do that.

Here's the controller I built to work with an external temp controller I have.

Thanks for the reply! I'm hoping this is somewhat temporary until I can get a pump and PID, but I don't think that's in the budget right now (although I need to get the brewhouse out of the kitchen). That's why I'll probably skip the switch or use a $10 240v 30A lightswitch for $10, skip the meter display, etc. I'll check the specs on that stilldragon and compare to the parts I'm shopping on Amazon (with 10% cash back on my Chase card!).

Edit: I think I can still do it cheaper on Amazon, but I need to know the pot value or if that makes a big difference, since stilldragon doesn't list that.

 

[truckmann]

The 470K pot you linked should work fine.

 

[doug293cz]

The value of the potentiometer does matter. You should pick closest one you can find to what the SSVR calls for.

The potentiometer sets the time before firing via an RC timing circuit. At low R settings, the triac will get triggered early in the AC cycle, meaning more on time and higher power delivery. At high R settings, the triac will get triggered late in the cycle, meaning short on time and lower power delivery. If the pot has too low a value, you will be limited in how low you can turn down the power. A pot rated at half the specified ohms, will only let you turn the power down to about 50% of max power. If the pot has too high a value, the power will go to zero without turning the pot all the way, you will only be able to use a fraction of the pot's travel range. Anything rated within about 20% of the specified value should have reasonable usability.

Make sure the pot is rated for use at 240 volts, as it does see full line voltage during use. The wattage rating should also be at least 120,000 / R, where R is the resistance of the pot.

Brew on

 

[truckmann]

I didn't mean to imply that the size the Pot doesn't matter just that the one he linked will work fine unless he has picked an odd SSVR. Most all of them on Amazon are 470K 2w or 470K-560K 2w and the Pot he linked to is a 470K 2W.