Please keep me from electrocuting myself(heatstick question).

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benko

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I'm thinking about constructing an electric dedicated heat exchanger for a HERMS system, similar to the one that The Pol was going to make for his. I'm looking at a 1500W, 120V heating element in a small (1-2 gallon) container. I'm incredibly paranoid about burning the house down (And I have this picture in my head of SWMBO standing over me with a baseball bat ready to hit me out of the way every time I plug this thing in).

Here are my questions for the electricians out there:

1. Will a Johnson A419 temperature controller be able to handle a 1500W, 120V heating element safely? It would be plugged directly into the controller, which would plug directly into a 20 Amp socket in my garage.

2. Is it even safe to use the temperature controller as my on/off switch for the heating element?

3. What type of insulation/waterproofing are you using near the bottom of the heating element to keep water from entering the wiring?

4. Does it need to be grounded, or can it simply be the heating element attached directly to a heavy-duty cord (with the connection being waterproofed) and then that plugged right into the Johnson controller?

Thanks. I know that similar topics have been covered, but I'm so paranoid about this that I was looking for answers specific to what I had in mind.
 
My A19 sheet says a max of 10A on a resistive switched load. 1500W / 120V = 12.5A. Too much.
 
i think pol is using an a-419 with no problem with the same heating element you are wanting to use. on the mcmaster website it advertises the a-419 at 15 amps max. part number 1760K77
 
I'm thinking about constructing an electric dedicated heat exchanger for a HERMS system, similar to the one that The Pol was going to make for his. I'm looking at a 1500W, 120V heating element in a small (1-2 gallon) container.
I'm planning that exact thing. I have one question though. Are you planning on building a heat stick, or mounting your element permanently in your heat exchanger? I have a 2 gallon water cooler that I plan on using. I will mount the element in the bottom of the cooler.
Here's an example of how someone mounted, sealed, and grounded an element in a cooler.


1. Will a Johnson A419 temperature controller be able to handle a 1500W, 120V heating element safely? It would be plugged directly into the controller, which would plug directly into a 20 Amp socket in my garage.
It looks like the spec sheet says it's good to 15 amps, so you should be ok.

2. Is it even safe to use the temperature controller as my on/off switch for the heating element?
As long as I read the spec sheet right, you should be ok. I'd make sure that you plug your controller into a GFCI outlet, though.

3. What type of insulation/waterproofing are you using near the bottom of the heating element to keep water from entering the wiring?
This depends on if you're building a heat stick or permanently mounting the element.

4. Does it need to be grounded, or can it simply be the heating element attached directly to a heavy-duty cord (with the connection being waterproofed) and then that plugged right into the Johnson controller?
Yes, it should definitely be grounded. The site I linked to above shows how to do it in a cooler. For a heat stick, I deviated from the cedar creek grounding instructions and drilled and tapped a hole in the element and attached my ground wire that way.

Here's a picture of building my heat stick. You can see the hot and neutral connections completely covered in JB Weld, as well as (kind of) see how my ground wire attaches.
heatstickJB.jpg
 
Huh. I got my JC from Northern Brewer. I'm looking at the spec sheet right now and it says 10A max for resistive loads.
 
Thanks for the great responses. Lustreking, it looks like we're building almost the same thing. I've also looked at smaller, ~2 gallon coolers. Here's another device that I found, that might work:

Bucket Heater

The advantage, for me, is that the heating element is already built, by professionals, and is designed to be submerged. I know it costs more (around $40) than making it myself, but I just don't feel comfortable messing around with this. Do you think the 1000W, 120V element would be powerful enough in ~2 gallons of water. It says that it will heat past 150 degrees, but doesn't give a volume. How long do you think it would take to get 2 gallons up to 170?

I'm also thinking about mounting it from the lid of the cooler downward, as opposed to the bottom up. I think that would mitigate some potential leakage issues. The actual cooler would remain completely intact, with only the lid having modifications. I'm thinking a hole in the middle to insert the heating element, a cutout on the side for the inlet/outlet of the copper wort coil, and possibly another hole for a small agitation motor, to keep the water moving inside the cooler to assist in heat transfer. I know that there'll be alot of stuff on top, but it doesn't need to be water tight, only somewhat insulated, since the water won't flow up and out. What do you think?
 
That's the exact cooler that I have, except mine is blue (and thus better :cross:).

The bucket heater should work, but it will just take longer to get up to temperature. If your controller is, in fact, rated for only 10 amps, you should be fine with 1000 watts.

What I'm planning on using for a stirrer, is something that I saw that someone else do. He just got an aquarium pump, and routed the line to the bottom of the exchanger and bubbled air up, thus creating constant movement of the water

Edit: I believe that he, too, used a bucket heater.
 
You took note of the GFCI suggestion, right? GOTTA have one of those.

I wonder because you said 20A outlet and 20A GFCI plugs aren't too common. Current code requires garages be protected by GFCIs (except dedicated outlets but they're usually a single socket).

Lowe's sells a portable GFCI for $12. You plug it into the wall and your cord into it. A GFCI outlet is $10 and if wired right will protect all the outlets downstream of it. Cheap insurance and it beats the heck out of the spousal baseball bat system!
 
Nice. I like it. I see you're not even using a lid. Does it hold the temp decently? Also, how long is that bucket heater taking to bring your heat exchanger water up to ~170?
 
Nice. I like it. I see you're not even using a lid. Does it hold the temp decently? Also, how long is that bucket heater taking to bring your heat exchanger water up to ~170?
My design is a little different than most HERMS. I use an external HERMS chamber (ie. I don't use my HLT). The small blue cooler's only purpose is to heat water for the HERMS coill (I call it the HERMS chamber). Before I mash-in I fill the HERMS chamber w/ water around 150-155F. After mashing-in, I set the PID to my desired mash temp, start the pump, and let it go. If for some reason my mash temp is too low, the HERMS can raise the temp about 1 degree every 3 min. Living in CO and brewing in a garage, I often brew in 50F weather and it never has a problem. My primary design goal w/ the version HERMS I have was to hold temps and to do small adjustments. It was never intended to do step mashes or even mash-out. I don't think the bucket heater is powerful enough for either.
 
I'm looking at doing the same thing. I only want to use a small cooler as a dedicated heat exchanger, not as a HLT. Do you use yours to bring your wort from mash temp up to mash out?
 
I'm looking at doing the same thing. I only want to use a small cooler as a dedicated heat exchanger, not as a HLT. Do you use yours to bring your wort from mash temp up to mash out?
I don't. I usually just start sparging w/ 169-170F water. My efficiency is in the high 70's so I haven't really needed to worry about mashing-out.
 
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