Controllerless electric boil keggle

[dmfa200]

Is that 18 amps from your element at max, or just in general? Not sure exactly how the infinite switch works, but if it's like a PWM, you could probably stick a cheap 40A SSR in that box with room to spare....and your overcurrent worries are over!

How does it do with being stuck to the side of a 200F keg?

I'd have to refer to my notes but I believe I'm drawing 18.3 amps max

If you'll look the switch itself does not contact the wall of my keggle. It is installed on the opposite side of the project box.
There are washers that space the box off the wall of keggle so there is very little surface area touching the kettle itself.
Like I said, 12+ batches so far and no issues whatsoever.

 

[dmfa200]

The 240v 15A infinite switch seems perfect as a cheap alternative. You can use a 3500W element and should be able maintain a boil on 12 gallons. I think I might actually like this better than a PID and SSR. It seems to give better control of the boil off rate. I might just be a little unsure how a PID is used to control the boil off rate. It seems a PID used for the BK is just trying to maintain 212F. Maybe someone with a better understanding could clear up the use of a PID on a BK.

Thanks for the idea on the infinite switch though!

$15 used infinite switch
$15 4500 watt element
$ 4 project box
$ 2 pilot light
$ 0 cord(free)

 

[dmfa200]

Cool, so yes a 15amp control. Do you have a GFCI on this circuit?

I know some of you are going to scold me, but no, not at the moment.
Just a 30amp circuit breaker.
If it makes any one feel better it's grounded properly.

 

[cyberbackpacker]

I know some of you are going to scold me, but no, not at the moment.
Just a 30amp circuit breaker.
If it makes any one feel better it's grounded properly.

Not to scold, but to inform anyone that may read this and take it out of context-- having it properly grounded does nothing to solve the problem that a GFCI is used for. The GFCI in basic terms reads a difference in current running through the separate legs, i.e. your body becoming a receptacle for current, and shuts off if this is detected. A ground cannot help you if this occurs.

Throw in a gfci breaker to this setup though, and very nice, easy, and safe!

 

[dmfa200]

Not to scold, but to inform anyone that may read this and take it out of context-- having it properly grounded does nothing to solve the problem that a GFCI is used for. The GFCI in basic terms reads a difference in current running through the separate legs, i.e. your body becoming a receptacle for current, and shuts off if this is detected. A ground cannot help you if this occurs.

Throw in a gfci breaker to this setup though, and very nice, easy, and safe!

I hope I didn't mislead anyone by making that statement.
I know I am taking a potential risk by not having a GFCI installed.
Thank you for reminding me. I don't think I should be taking any chances
with my life.
I am going to put in a GFCI before I brew again.

 

[conpewter]

Good to use a GFCI if you can. I have it on my system (inline GFCI in the 30 amp cord). I know you can get buy without it, and if you build everything right it is still pretty safe, but better safe than sorry.

Also I found out that you can use an infinite switch with a relay. Not sure of the mechanics of it but was told that is how most higher amp applications are done if you want to use an infinite switch.

 

[pvtschultz]

I think that you're onto something. I did a bit of digging and came up with this:

http://www.duralite.com/store/scripts/prodView.asp?idproduct=87

It doubles the cost, but ups the current capacity to 30 Amps. You'll have to make sure the coil and load voltage is 240 VAC.

I am assuming the rate that the bimetallic strip oscillates is going to be dependent on load since it is a conductor and makes or breaks the circuit. In that case, you'd probably need a pair of heating elements; the first being controlled by the infinite switch and then the other will be controlled by a relay connected to the contacts for the first heating element. You might have better control just using a pair of infinite switches and a pair of elements to reduce the heat input fluctuation. But, I'm a mechanical engineer and not an electrical one, so you'll have to take my opinion for what it is worth to you.

 

[conpewter]

I think this is why I just went back to a PID, at $40 or something like that it wasn't that much more expensive since I needed the SSR either way.

The infinite switch plus SSR would save a little money. But as mentioned by pvtschultz you'd have to make sure the infinite switch gets a big enough load, and your SSR is rated to take that sort of amperage as a signal. With the smallish difference in cost, the PID gives you a lot more versatility... unless I can find a stand-alone 30 amp infinite switch.

 

[conpewter]

If I could put together a single keg (with plug for optional 2nd keg/kettle) PID controlled electric boil kettle for around $450 shipped, do you think there would be any buyers?

That would be with
15' 30 amp (240V) GFCI protected cord
Stainless keg
installed element
bottom drain (Sanke attachment)
1" - 3 piece valve, reduced to 1/2" camlock (or other QD)
Hop screen (whole hops)
PID Controller in attached project box, with temp probe

So that would be either your BIAB single vessel system. Or buy additional keg with just element and cord to plug in to the controller, so you can have your HLT/BK combination, but only one controller. Would need a 4 prong 30amp outlet (like for newer dryers).

Might have to build mine before I can really explain it, so I could have pictures.