Using RIMS to boil

[DaveSeattle]

I have only 120v service, but a 20A circuit and 2 15A circuits, and I am converting my 5G system to all electric. HLT and RIMS work fine, but I'm not sure about the kettle (a keggle).

Currently I have a 2000 watt element in the kettle, which doesn't seem capable of reaching or holding a boil on its own. I would like to just run my RIMS during the boil, but I'm concerned that the liquid will boil when it hits the element and that will cause vapor lock in the (silicone) tubes and potentially dry fire the RIMS or scorch the wort. The loop goes kettle->pump->RIMS->kettle. Do I need to worry about this or will it work just fine?

I could add a second element to my kettle but I'd also need new SSR, outlet, wiring, box, etc., and it'd wind up costing like $80 and adding yet another set of wires.

I could also merge two circuits into a 240v if they are properly phased (not sure how to tell), but from what I can tell, there's no way to do this and stay in code.

 

[BrunDog]

You could use the RIMS to heat up toward the boil faster but not use it at or during the boil. It won't vapor lock but it will spit steam if the liquid books in the tube. Not desirable.

 

[DaveSeattle]

Why would it be undesirable to spit steam? The outlet is deep in the boiling wort. Or would it cause flow problems?

 

[schematix]

You're going to have a very difficult time pumping the boiling wort with most common home brew pumps. The vapor pressure of water is so high at boiling that you likely won't have much, if any, NPSH. Thus your pump will cavitate. You could definitely use it to heat the wort faster though.

 

[DaveSeattle]

I was able to pump boiling wort with this setup before with the RIMS out of the loop, when I had the kettle on a propane burner. The pump is before the RIMS and about 2-3 feet from the kettle so the wort has cooled slightly by the time it gets to the pump.

 

[BrunDog]

I think it will pump just fine but trust that steam is not something you want happening.

However, if you want, go ahead and test this with water. See what happens and report back.

-BD

 

[smcinco]

I doubt the venturi/cavitation will do wonders for your equipment.

 

[DaveSeattle]

I still don't get why steam after the pump would be a problem? It's going to pass through stainless steel, silicone, and copper, all of which will easily tolerate the temperature. FWIW I think cavitation shouldn't hurt a magnetic drive pump either, but it's not an issue here. Again I have run this pump for hours with boiling wort with no issues.

I found another solution, one of the outlets I'm using is the only one on the circuit so I can upgrade it to 240 volts and just use one big element.

 

[BrunDog]

Whoa... You can't just "upgrade" the outlet. It has wires and a circuit breaker that feed it. They need to be appropriately sized, AND *should* met NEC.

 

[baulz]

Why not add the 2nd element in the kettle, unplug the RIMS and use that outlet to run it?

I'm similar to you with a 20A circuit to power a 2000W HLT, and 15A circuit to power a 1375W RIMS. When I convert the boil kettle to electric I will use 2 elements and use the existing circuits. I will never need to power all 3 vessels at the same time.

EDIT: Forgot to add I currently use the RIMS to heat the wort in the BK to almost boiling temps. Always me to walk away and spend time with the family, with 2 young kids I always have to split the brew day up.

 

[DaveSeattle]

@BrunDog: I know the code and will be upgrading the breaker and getting an inspection. You have to change the breaker to get 240 anyway. The required wire gauge is the same for 120 and 240 volts so no concerns there.

@baulz: My system is mostly automated so changing plugs is no good. And I'd rather not drill another hole in the kettle. But this is my backup plan I would have to add another SSR and external outlet from the controller to avoid changing plugs.

 

[nacho2100]

As blasphemous as this is there are reports of systems that use heaters and pumps that don't boil (picobrew zymatic) instead it brings it up to 207. Try this and see if that works for you.

 

[DaveSeattle]

I found a way to get 240 volts put in cheaply, so I converted the HLT and kettle to that. Still waiting on some parts to finalize it but it will make brew day much faster.

 

[alphaomega]

I know ppl who brew like this and it works, however pump cavitation most certainly is an issue. Pumping wort that is boiling hot and wort that is actually boiling is not the same thing.
I second @nacho2100, there is no need to actually boil the wort if you are pumping it. Just go near boiling. There is nothing magical with boiling temperature, you can still brew beer if you live at an elevation. It is the movement of the wort that is important, not the last few degrees.

 

[FuzzeWuzze]

@BrunDog: I know the code and will be upgrading the breaker and getting an inspection. You have to change the breaker to get 240 anyway. The required wire gauge is the same for 120 and 240 volts so no concerns there.

Yes and no, its the amperage you care about...but you wont usually see people pulling wire for 30A 120V Service in construction..most houses are only wired for 20A 120V service and thats generally only in the kitchen for fridges and the like.

On top of that I cant think of ANY reason why someone would pull TWO seperate hot lines to a single outlet.

So yes on the off chance that you have 4 wires(2 seperate 120V, Ground, and Neutral) going there then yes you can do what your stating ...but I'd be surprised if its wired like that.

I hope your not under the impression you can just swap a 120V breaker with a 240V breaker and call it a day. If so your probably in for a rude(and expensive) awakening when that Electrician comes to fix your failed inspection

 

[DaveSeattle]

There is no wiring difference between a 3 wire 120 volt and 240 volt circuit except the color of the wires and the breaker and its connections in the breaker box. You have to convert all outlets on the circuit, but this circuit only has one. You disconnect the neutral from the existing circuit in the breaker box and connect it to the other hot pole of the 240 volt double pole breaker. You have to label both ends of the white line that is now hot and use the correct 3 wire 240 volt outlet type. And obviously the ratings of the breaker, wire and outlet must remain consistent with the amperage, which I'm not changing.

 

[DaveSeattle]

Just to add further detail, it's a 20A circuit on 12/2 originally intended for a vacuum system. The circuit won't support 120 volt operation, which is what the neural is for in a 4 wire 240 volt installation, but my use doesn't require that and neither does code.

 

[FuzzeWuzze]

Alright just make sure you stay under 20 amps...you shouldnt be running a full 5500W element for example on 12 gauge wire. 30 Amps should use 10 gauge.

 

[DaveSeattle]

Yep, I'm running 4400 watts, which is about 500 more than the continuous load rating for 12 gauge but this load won't be on for 3 hours straight which is the NEC definition of continuous.

 

[augiedoggy]

Yep, I'm running 4400 watts, which is about 500 more than the continuous load rating for 12 gauge but this load won't be on for 3 hours straight which is the NEC definition of continuous.

I've got 4 "4500w" elements and the most any of them put out 4,4xx and it draws 18.6 amps... They are all less powerful than their max rating. The 4500w element I just bought from Kals site only puts out 4230 watts of power and draws less than 18 amps.

 

[DaveSeattle]

I've got 4 "4500w" elements and the most any of them put out 4,4xx and it draws 18.6 amps... They are all less powerful than their max rating. The 4500w element I just bought from Kals site only puts out 4230 watts of power and draws less than 18 amps.

This is expected and isn't the fault of the element - a little bit of voltage gets "used up" by the wires and switches/SSRs. Also as I understand it the voltage from the grid can vary a bit too

 

[augiedoggy]

This is expected and isn't the fault of the element - a little bit of voltage gets "used up" by the wires and switches/SSRs. Also as I understand it the voltage from the grid can vary a bit too

It is the element when I have 4 of them and they all consistent ly draw different respective max amounts of power... For example my HLT element puts out 4462 watts as long as my volt meter is showing a full 240v available unlike my boil kettle element which puts about just over 4200 watts on my meter with the same 240v of working power. Wiring and switches can eat up a few watts maybe but not hundreds in this case. When the manufacture the elements they have tolerances and as long as they are close to say 4500w without drawing over that amount they are sold as that size. I have a 1000w element that puts out under 800w at the full 240v. They are rounded up to the next standard size when sold in some cases.

 

[DaveSeattle]

If you're actually measuring 240 volts at the element then yeah, that coupd be variance in the elements. You would expect different voltage and wattage at the elements if the wire lengths were different, especially if the outlets were chained, but I think not of the magnitude you describe, and obviously measurement wins.