Aluminum E-HLT

Hey all,
I am still trying to design an E-HLT that can run off 120v service and requires no more DIY skills than i possess. Please tell me if you see any potential problems with this setup.

I would use a 2000 w element if you are on a 20 amp breaker. I just built one with a 2000w element with fiberglass insulation and it takes almost an hour to heat up 8 gallons to around 165.

thanks sapperxl,

I thought i heard somewhere that the 2000w elements draw too many amps for the temp controller... is that true or just something i made up in my head?

no, that is most likely true in your case too. I burned out a ranco ETC several years back with my first eHeat exchanger build trying to use it to power a 2000w 120VAC element. your safest bet would be to incorporate a relay that the temperature controller controls, and the relay will supply the power to the element.

something like this
http://www.frys.com/product/1667853?site=sr:SEARCH:MAIN_RSLT_PG

thanks bsquared,

I wanted to try to avoid as much wiring as possible for safety reasons. I know the johnson is nema 4x rated and i figured i could get another nema rated enclosure for the rear end of the element. Is it really impossible to use the 1500w element? i don't mind waiting a while to hit mash temps (it will give me time to clean and sanitize all post boil equipment). I think thePol uses 1500w but he might have 2 of them.

Sorry I didnt know the temp controller wasn't rated for it. I used a aquarium controller and ssr on my ehlt. You can get around long warm up times by throwing in some boiling water from your brew kettle. I do that when I do 10 gallon batches, a little dangerous though.

I wanted to try to avoid as much wiring as possible for safety reasons.

Click to expand...

i understand people erring on the side of caution vs overestimating their abilities when safety is concerned; but if you can read a diagram and are careful in your work theres no substantial difference in wiring that johnson controller vs wiring a whole control panel.

and if you are truely not skilled enough to work with mains power to begin with, you shouldnt even be playing around "a little bit" with that johnson controller. it can kill you just as easily as anything else 120v. to me, its like someone justifying using heroin by saying "well, ill only do a little bit". that doesnt make it any safer and doesnt make you any better at doing it, its just an arbitrary limit. and we all know a johnson controller is a gateway drug to RIMS tubes and full automation, so you might as well learn now before you get into the hard stuff...

anyhow, moving along-
2000w will put you at around 16.6 amps @120v. your controller is only rated at 16amps, max. if you dont want to have to plan far ahead for hot water on 1500w, you will need an external relay. since you want to keep it simple, you can pick up an AC-to-AC SSR or mechanical relay (eventhough its arguably more dangerous using high voltage AC as the switch signal, as opposed to using low voltage DC; its just simpler wiring). if that johnson controller has a DC output signal, then you can get a DC-to-AC relay, and not need more 120v lines running around the place. (not sure if it does, i didnt look at the manual)

sapperxl said:

You can get around long warm up times by throwing in some boiling water from your brew kettle. I do that when I do 10 gallon batches, a little dangerous though.

Click to expand...

kind of defeats the purpose, no?

Bsquared said:

no, that is most likely true in your case too. I burned out a ranco ETC several years back with my first eHeat exchanger build trying to use it to power a 2000w 120VAC element. your safest bet would be to incorporate a relay that the temperature controller controls, and the relay will supply the power to the element.

something like this
http://www.frys.com/product/1667853?site=sr:SEARCH:MAIN_RSLT_PG

Click to expand...

A bit off-topic, but I have a question that pertains quite a bit to this very post.

I've been reading up on relays and the material makes it seem like it's necessary to have some sort of overvoltage protection on the relays in a circuit, so that components don't get damaged when it switches.

In a DC circuit, it seems like a very simple diode is all that's necessary, but in an AC circuit, it gets a bit more complicated, and I'm having a hard time figuring out exactly what I'd need for my particular project.

The only "delicate" thing in the circuit is the temp controller though. So I'm wondering... will it damage my temp controller if I just skip overvoltage suppression stuff altogether? Or is it REALLY that necessary?

I get better temperature control with my ehlt then I did when it when it was direct fired, plus I fly sparge so it keeps my water exactly where I need it without having to mess with it, so preheating in a kettle does negate some of the benefits of an ehlt but not all.

alright audger,

you have inspired me to just build a control panel with a pid, ssr and e-stop. i will probably get a larger enclosure than i need, for when i decide i want a herms and need to have a pump wired in. Im sure i will have a few more questions as time goes on but for now i have a good start. i will post a wiring diagram when i have some time.

P.s. what part of Connecticut are you from, i lived there for 22 years?