I’m looking to add a 240V 4500W heating element to a kettle.
I had previously expected to operate it with a switch, but was informed by a friend that this is a very bad idea & will likely fry the switch in short order.
I’ve looked at the control boxes on highgravitybrew.com & am not entirely impressed.
I think my $ would be better spent on something a little more accurate.
Does anyone have the ability to instruct me on how I would go about using a SSR & PID, to control my element?
Can anyone provide wiring diagrams, for a very basic build?
I supposed I should also mention that I’m planning to use the element in my boil kettle to maintain mash temperatures, via HERMS coil.
So…The element will not be strictly a boil element…I will need to be able to control any step mash temperatures, as well.
Kit B - are you a member of the Northern Brewer forum? There is a very knowledgeable electrician over there who likes this type of stuff and would probably be a big help to you.
Ok, 4500 watts @ 240V is about 20 amps so I recommend a 50amp SSR. You would put the temperature probe in the mash tun and then when you are ready to boil, switch the PID to ON/OFF mode and dial it up to 100%. When the kettle gets going, dial the PID back to whatever % will maintain a rolling boil.
if you use a 25 or 30 amp SSR with a 20AMP load then you HAVE to put a heat sink on it, then what do you do when you decide to put a 5500watt element in the kettle?
You can get a 50A SSR with heat sink for $23 on Ebay with free shipping. Less from China. I don’t care for the SSRs that Auberins offers.
I also recommend one of the 4500 or 5500 watt ‘Sandhog’ super low watt density elements to help prevent scorching the wort.($35)
Paul,
The 80% metric is for circuit breakers and electrical wiring. Those SSRs generate a LOT of heat when they are on 100% and we all know heat is bad for electronics. The cost difference between a 25 and 50 amp SSR is negligible compared to what a PIA a failed SSR on brewday is going to be.
I would always double, if possible, the SSR rating per the current requirements. Also, that heatsink needs ventilation, so don’t plan on putting it in an enclosure.
Also, you can get PID controllers form Ebay for around $20, also from China and they work well.
I just looked and the panel I am buying has 2 5500W and 2 40amp SSRs with a giant heat sink, so its probably in the middle of what you’re recommending.
The GIANT heatsink is the key. 5500w@240V is 23amps so you’re pretty close to double WITH a heatsink. I am using 120V with my system(2X11.5 amps with one 40 and one 25A SSR it’s great for the RIMS buy it takes 2.5-3hrs to heat up my HLT. I just use aluminum supports to mount my SSRs and that seems to be enough heatsink. Mounting the SSRs on a metal box makes the box a heatsink too.
The Aubers are LDG. They WORK very well, they just have a cover that does not want to stay on once the wires are connected so I have to hold the cover on with a zip tie.
One last comment. In my considerable experience with this type of hardware. There ain’t nothin’ simple about it.
On the flip side, once you have the system dialed in, the repeatability is fantastic.
This is what I’m looking to do as well, but bigger. With my setup, it’s 4 heat sticks, 2 for the hlt and 2 for the boil kettle, 4.5kw each, so at 230v that figures to 25 amps per stick, right? In terms of buying SSRs, does that mean I need four 25 amp SSRs, or can I get by with two 50 amp SSRs? For the total load, if I’m running the boil kettle and the HLT at the same time, does that mean the whole system will draw 100 amps? (calculations include 80% safety thinger mentioned above) Should I just never ever have both turned on?
Each of your sticks will require 20 amps, if they are truly rated for 4500 watts at that 230VAC. I say that because you might be inclined to use elements designed for the US which is 240 VAC. Not a big deal, but the current/wattage would drop a little if you did.
If it was me, I’d use a 50A SSR for each of them. That does 2 things. It gives you a safety margin and it spreads out the heat on the heatsink(s). Plus the price difference between a 25A SSR and a 50A SSR isn’t that much.
Phil,
The price difference between a 25A and 40A SSR is only about $4 so I would go with 4 X 40 (one for each stick) and wire the SSR trigger wires in parallel so you will control both SSRs simultaneously. If you try to use one 80A SSR for two sticks (doable) then you have to deal with 50 amp wiring (pia). And yes you will need a 100A service to the shed if you want to run HLT and kettle at the same time. Depending on your situation, you could probably run 4 25A breakers from a panel in the shed cheaper than 2 50s.
Thanks, Bryan.
I really should have asked you directly, before.
Sometimes I guess I feel like I lean on you, too much.
I found exactly what I needed, here:
The only thing the diagram seems to be missing is the thermocouple connection.
I’m also struggling a bit with placement of the thermocouple.
If I buy a 4", it gets far enough into the mash to be more accurate than a 2", but it goes in far enough that I think I might be constantly smacking it with the paddle.
Not sure how to ensure proper placement…Battling with myself, over this.
If it was me, I’d move that switch to the input legs, so you shut down everything when it’s off. In that schematic, the controller comes on as soon as you plug it in.
