Dedicated Herms Guide, Problems And Solution Thread

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Hey folks, I'm looking for some advice about RCDs/RCBOs/MCBs for my HERMS control panel. Currently pre-HERMS, I've been running a 2400W element (urn) and a March 809 pump (168W based on it drawing 0.7A) concurrently on the same 10A circuit. The house's circuit breakers (overload only, I believe) don't trip, so I'm assuming they're rated for 16A, unless there'd be a bit of "overhead" on 10A breakers?

I'll be putting RCDs in the control panel. Looking at suppliers like this, for example, it appears that most RCDs are combined with MCBs, so unless there's a compelling reason not to do so, I'll get the combined device (known I believe as an RCBO). My question is, if I go for a 10A version, is it just going to trip every time I fire up the element and pump at the same time? Or, if I go for a 16A, is that sufficient excess that if the circuit is somehow overloaded, something might burn out or catch fire?

There'll be other low-wattage stuff in the mix too: 2 Sestos PIDs, 1 STC-1000 and a 12V DC power supply.
 
I completely re plumbed my system making sure all my lines were as short as possible and my pump was much lower than anything else.
So you find that the pump has to be at the lowest point? I was looking at having it quite close to the MT, but can make it lower if it helps make things easier.
 
I have a theory Id like some feedback on..

as documented Ive made this little HEX unit.

Capture.JPG
(inlet at the top and outlet at the bottom)

Its going to be a little different to the image pictured in the (hopefully) final build but it dawned on me that I can have another purpose for it... here it is...

At the end of the boil, can anyone see a reason why it couldnt also be used as a chiller? all I would have to do is add some ice to the pot when Im ready to drain off to the fermenter? Hook it up to the kettle and outlet to the FV

I generally run off quite slow and the thought is that surely it would drop a significant amount of temp with a slow run through the coil.

Im a few weeks off both the build and my next brew so plenty of time to tinker with it.

Thoughts?
 
Hi Yob. I think cooling would be far more efficient if you added the wort to the pot and pumped water through the coil.

I thought about that but dont want to waste the water as I dont have tanks (yet) and the pot is too small for a full wort...

was thinking that if the run off was slow enough it might do the job... I might just have to do a 10lt wet water run and see what it does and what temp I can get it down to.

:icon_cheers:
 
Your problem will be with the volume of water in the HEX compared to the volume of wort. If you had equal volumes, and 100% perfect exchange, you'd end up with water and wort at the mid point between the temperature of the two.

So if you had 0deg water, and 90deg wort (assuming some natural cooling during the whirlpool), you'd only get down to 45deg. And that's assuming 100% efficency, which you won't get. And assuming equal volumes, but I assume your HEX pot is smaller than your boiler?
 
Your problem will be with the volume of water in the HEX compared to the volume of wort. If you had equal volumes, and 100% perfect exchange, you'd end up with water and wort at the mid point between the temperature of the two.

So if you had 0deg water, and 90deg wort (assuming some natural cooling during the whirlpool), you'd only get down to 45deg. And that's assuming 100% efficency, which you won't get. And assuming equal volumes, but I assume your HEX pot is smaller than your boiler?


... well.. will be 23lt of wort in the kettle V's 20 lt pot.... but I see your point... if I only get to 40ish deg then not really worth it.

:icon_cheers:
 
Did my first batch on the new system today. Everything went very smooth and as planned except for a loss in efficiency of about 10%. Last two batches were 87% and 85% mash eff but this first herms batch was only 76.5% (all mash efficiency)

My old process:
Mash in at 2.8L/kg single infusion, then add boiling water for a mash out followed by a single batch sparge of with the remaining water.

New process:
Mash in at with 2.6L/kg and set herms to recirc for 60 min, then ramp to 76 for mashout for 10min follow by a 20L batch sparge.

Not really sure what could have caused the loss in the process.

Here is some pics of the setup to help give a better idea. I can attach larger ones if need be.

IMG_1494__Medium_.JPG IMG_1495__Medium_.JPG
 
is that your probe in the second photo? you have alot of line to get to before it gets to the temp probe...You want it on the outlet of the HEX.. (many thanks to those that suggested it to me) and also you could do with insulating those lines to aid in temp stability.. you could probably get away with shortening the lines a bit from the look of it.??

How is the temp measured at the HEX?

Im tipping temps were the issue here and recently Ive just got my system screwed down and eff. has boomed.

I made a little home made t piece a while ago here earlier in the thread... sure its cheap and nasty but it comes together in the end :)

hope that helps man.

Capture.JPG

:icon_cheers:
 
Yeah I saw that, great bit of ghetto handy work!

I was reading and notice people tend to measure at the exit from herms or at wort return to the MT, so where it is places in the tube I believe it should be getting a good temp reading as it enters back into the tun. I'm trying to figure out if this monitoring position could really cause the temp diff. If anything, the wort would be slightly warmer then at the exit then at the return so not sure how the issue would effect the mashing. I didn't read the grain bed temp at all during the mash.
Not sure which thread or who posted it but I remember reading the that wort returning is the temp to hold, as all the enzymes are working in the liquid not the grain bed.

I had it initially set up to your suggestion but reading truman's issue with the pump placement I follow the advice there and have how it is now, I'm having no issues with it so I'll leave it as is for now.

Btw, how awesome is paint? haha


Edit to add:
All thats really changing is the way I'm measuring the wort and the addition of a recirc so other then you're suggestion I'm stuggling to come up with other causes.

How cool does the mash have to be to not convert properly anyway? At a guess the worst the bed could have been was 62-66 during the sacc rest.
 
I had it initially set up to your suggestion but reading truman's issue with the pump placement I follow the advice there and have how it is now, I'm having no issues with it so I'll leave it as is for now.

I ended up turning my pump around so the body is at the highest point. See this post here

Pump placement

After having it fail twice due to crud getting into the bushes I cleaned it out and now run it with the body of the pump higher than the inlet so there's less chance of wort getting into the body. So far so good the pumps been running fine without and issue.
 
I was reading and notice people tend to measure at the exit from herms or at wort return to the MT, so where it is places in the tube I believe it should be getting a good temp reading as it enters back into the tun.

as I understand it , the enzymatic reactions are taking place in the hottest parts, ie the HEX and it may well be much hotter there than the end of the line, especially if the line's not insulated, this can have possibly resulted in a bit of a false reading on where you expected it to be meaning your mash temps could be out not producing the profile of wort you were expecting and resulting in efficiency loss..

least that's the way I understand it.. and it seems to make sense that you control the hottest bit :)

:icon_cheers:
 
It is more like you want to be able to control the hottest point of your mash so that you are not denaturing enzymes. At least from my perspective.

If you had a large lag, e.g. 5 degrees C, and you had your heat exchange set for 69C, though the main portion of the mash was catching up at 65C, you should have beta and alpha amylase activity in the mash, but only alpha in the heat exchange. So you should have one constantly active enzyme (alpha) and another which is active, though deanaturing as the whole mash warms up.

If you controlled at the wort return to the tun, there should be very little loss, obviously depending on the length of tubing from heat exchange, but theoretically you might be able to come up with some kind of mash schedule where you were denaturing an enzyme which you wanted to be active, especially in the beta/alpha crossover temperature area of saccharification.

ED: this is all more pertinant if you wanted to control your mash temp from, say, the entry to the heat exchange (basically coolest point), and there was a large lag. If this were the case, you could fry all of your enzymes because it might tell the PID to crank the element full stick until it sees a change in temp, though in this time, you may have brought a significant portion of your mash past mash-out temperatures.
 
I think I'll re-plumb my lines and shorten them then try to work out some insulation from the HX to the MT. During the next brew I will also take readings at the grain bed and see what type of difference I'm getting.

I am trying to avoid measuring from the HX out as I don't have to buy a whole heap of fittings and **** to get it there. At the moment all I have is a hose clamp which is real easy haha.

Is it worth insulating the MT as well? Its SS so I'm not really sure.
 
Yes, insulate your MT, this will reduce work for your HX element and should reduce lag.
 
insulate as much as you can to aid in temp stability is my goal, Im still using the esky mt so I dont really have to worry about that bit... yet...

That T-Piece I made up is just a bit of silicone hose with a copper T piece, the only drawback is once the probe is siliconed into place it's sort of there for good, but as my HEX is CIP I dont really worry about it :)

Cheap but effective and I didnt have to buy all sorts of bits and pieces (bling factor only for me) first runnings was 1093ish last brew.

I find that my MT lags about 1-2'c behind the HEX when ramping so pretty happy with that sort of performance.. Ive actually calibrated my HEX controller to the mashmaster in the MT.. if it's out, at least I will be consistently out ;)

Yob
 
Just a quick update:
Went to mess around a bit after advice given and rig now looks like this, shorter (sort of) lines, pump inlet down and probe inline after HX. I just put it under the silicone hose and tightened the **** out of it and no leaks so far.
IMG_1497__Medium_.JPG IMG_1498__Medium_.JPG

What materials and from where are people using to insulate their hose lines?

Another thought that crossed my mind is possible channelling during the recirc? Depending on how that steamer thing (wort return) was performing I may have had an issue there. Can anyone see any problems there? (photo above). Can channelling cause an issue with recirc or batch sparging?
 
Just a quick update:
Went to mess around a bit after advice given and rig now looks like this, shorter (sort of) lines, pump inlet down and probe inline after HX. I just put it under the silicone hose and tightened the **** out of it and no leaks so far.
View attachment 56284 View attachment 56285

What materials and from where are people using to insulate their hose lines?

Another thought that crossed my mind is possible channelling during the recirc? Depending on how that steamer thing (wort return) was performing I may have had an issue there. Can anyone see any problems there? (photo above). Can channelling cause an issue with recirc or batch sparging?


Hmm, agree with most above re placement of the probe nearest to the hottest point of the closed system. A few things I would try. Use a rounded volume of around 2.75 - 2.8 L/kg. Add water to the tun and begin recirculation, when the recirculating water temp is stable at your mash temp add the grist and stir only a few turns. After 30 seconds to allow for grits and flour to clear the pump head throttle back the pump output to prevent compaction of the grainbed (I use about 1/4 throttle). Temp will drop back slightly after adding the grist, once the recirculating wort is back up to temp start your mash timer. My best eff 92%+ comes at 75 min rest length, 90 min gives no further improvement, 60 min results in lower eff. After the timer goes off at 75 min lift controller set temp to 77C for the mash out rest. After 10 min or so check recirculating wort temp, if up to mash out temp (77) give the mash a few gentle turns with the mash paddle then set the timer for a 10 min mash out rest. I continuous sparge with water at 77 pumped via the HEX to maintain temp while gravity draining at .5L/min to the kettle. If batch sparging add sparge water as normal.

Watch mash times, there is a sweet spot with all systems, lengthen out the sacch rest time by 15 min, if you note a gain in eff lengthen again by another 15 min, repeat until there is no further increase in eff. Be sure your recirculating wort is at temp before starting the mash timer. Recirculating slowly reduces channeling and allows for a more open grainbed. As you will now not have high combined temps you should notice a marked improvement in attenuation.

Cheers,

Screwy
 
What pump are you running Screwey?

I wouldnt think those little brown pumps need much dialling back, least it doesnt seem to on my system anyway... first to admit that Im fairly new to pumps and am still fine tuning small areas :)

If you are worried about channeling, at the end of recirc JZ often talks about taking a bread knife to the bed (only 3/4 deep of course) and 'slicing' the bed criss cross to help with this... too much effort for me though ;)

Yob
 
What pump are you running Screwey?

I wouldnt think those little brown pumps need much dialling back, least it doesnt seem to on my system anyway... first to admit that Im fairly new to pumps and am still fine tuning small areas :)

If you are worried about channeling, at the end of recirc JZ often talks about taking a bread knife to the bed (only 3/4 deep of course) and 'slicing' the bed criss cross to help with this... too much effort for me though ;)

Yob


Ordinary old garden variety March, 9L/Min but you don't need em going flat out. And stirring raises flour into suspension which then returns to cover the grainbed in a grey impervious layer, this will cause channeling, you will see a grey muddy layer with a gap around the outside of the grainbed where the wort has been channeling down the sides not through the grainbed.

Screwy
 

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