Control Panel help. Dual voltage RIMS panel with PWM.

[CoalCracker]

Looking to build a small panel for a future RIMS build. I have a few requirements.

1. Be able to use either a 120v or 240v power source.
- Brew indoors during winter, garage on 240 during summer.
2. Use a 5500w element for the RIMS, switchable between wattage. 240 to heat sparge / strike water, 120v for recirculation.
3. That same circuit should also allow for either PID or PWM with a selectable switch to run either or. PID for RIMS, PWM for BK.
4. This circuit should only have one output, I will switch kettles manually.
5. Disconnect on the RIMS heat source. Prevent dry firing of element. (Nice to have but not neccessary.

I have seen some diagrams that get very close to what I want, but nothing exact. Mainly the switchabilty between voltages. This will be one or the other, I don't plan on running 120v and 240 at the same time, other than powering a pump.

I'm open to all ideas!

 

[doug293cz]

The solution for PID and PWM is the Auber Instruments DSPR120 (or DSPR300.) This unit uses a control algorithm that actually performs better than a PID for mash temp control (and is easier to adjust if needed), and also provides a dial controlled PWM for controlling boil power. It also has mash and boil timers, as well as a rapid heat to boil then automatically drop power to sustain boil function. Pretty much everyone who uses one of the DSPR units recommends them over a regular PID.

Multiple input voltages is different, but I think I can figure out a way to do it. Stand by.

Interlocking the RIMS element so it won't turn on without the pump running (to prevent dry fire) is simple, but then the interlock needs to be bypassed to run the element in a BK. And, adding the bypass to the interlock, pretty much makes the circuit just as error prone as a circuit without a bypass.

Brew on

 

[CoalCracker]

The interlock was just a plus, I've been brewing long enough that I don't fore see myself running the element without the pump.

Voltage flexibility is the biggy. If there is a way to throw a disconnect to take one leguy from the 240 wouldn't that work as well?

 

[doug293cz]

The interlock was just a plus, I've been brewing long enough that I don't fore see myself running the element without the pump.

Voltage flexibility is the biggy. If there is a way to throw a disconnect to take one leguy from the 240 wouldn't that work as well?

To go from 240V operation to 120V operation, one hot leg needs to be connected to neutral. This would be dangerous to do with a switch, because if it was plugged into 240V with the switch in the 120V position, you would short a hot to neutral. You need two different wall plugs anyway for the different voltages, so the safest way to do the switching is to hard wire the hot to neutral connection in a short jumper cable that has a 120V plug on one end and a 4 wire 240V receptacle on the other end. I can't see a way to get an accidental hot to neutral connection this way.

And, most of us never foresee making the simple mistakes that we do make.

Brew on

 

[doug293cz]

Ok, here's my interpretation of what you asked for. Actuating the SW4 switch energizes the R30A mini power relay to enable 240V output, but only when plugged into a 240V outlet. When plugged into a 120V outlet, you get 120V output for either position of the SW4. The 5-15 to L14-30 adapter cord allows you to plug the panel into a 120V outlet by turning one of the hot lines in the L14-30 into a neutral. The L14-30 plug and receptacle must be wired exactly as shown, or things won't work so well (if at all) when trying to run from a 120V source. For 240V input you need a 30A GFCI protected outlet. For 120V input you need a 15A GFCI protected outlet. Let me know if you have questions or comments.



Brew on

 

[stamandster]

Ok, here's my interpretation of what you asked for. Actuating the SW4 switch energizes the R30A mini power relay to enable 240V output, but only when plugged into a 240V outlet. When plugged into a 120V outlet, you get 120V output for either position of the SW4. The 5-15 to L14-30 adapter cord allows you to plug the panel into a 120V outlet by turning one of the hot lines in the L14-30 into a neutral. The L14-30 plug and receptacle must be wired exactly as shown, or things won't work so well (if at all) when trying to run from a 120V source. For 240V input you need a 30A GFCI protected outlet. For 120V input you need a 15A GFCI protected outlet.

Brew on

Similar to how i would do it, except when making the converter pigtail I wouldn't tie the L2 to neutral just in case that pigtail got plugged accidentally into a different system.

 

[doug293cz]

Similar to how i would do it, except when making the converter pigtail I wouldn't tie the L2 to neutral just in case that pigtail got plugged accidentally into a different system.

Yeah, the design would still work that way, except that when plugged into a 120V outlet, there would be no power to the element if switched to 240V mode (with the SW4.) Not sure why anyone would ever want to plug any other 240V, 4 wire device into the pigtail though. Even if they did, isn't the worst that happens is the 240V device only gets 120V? I've tried to think of failure modes for that scenario, but haven't come up with any yet.

Brew on

 

[Bobby_M]

The real issue is that you won't be happy at all brewing on 120v. Maybe I missed something but will you be augmenting the heat input with a stove on 120v?

One thing to realize is if you use the EZboil unit, you really don't need to switch it down to 120v for the RIMS recirc since the power regulation is extremely granular.

 

[Beernip]

The real issue is that you won't be happy at all brewing on 120v. Maybe I missed something but will you be augmenting the heat input with a stove on 120v?

One thing to realize is if you use the EZboil unit, you really don't need to switch it down to 120v for the RIMS recirc since the power regulation is extremely granular.

Looks like SW4 turns on/off the second leg to the element converting it from 240 to 120v.

Looking at the DSPR you can control power or set it to hold at a temp. I don't see where you can do both though. He will want the RIMS element to run at 50% power while maintaining mash temp.

 

[CoalCracker]

Looks great thanks!! I wasn't notified of the replies.

While on 120 I will be supplementing with gas on a stove top. I currently do that and get a hard boil.

I'll take a better look at this tonight when I'm in front of a pc.

 

[doug293cz]

Looks like SW4 turns on/off the second leg to the element converting it from 240 to 120v.

Looking at the DSPR you can control power or set it to hold at a temp. I don't see where you can do both though. He will want the RIMS element to run at 50% power while maintaining mash temp.

If you turn one leg to the element off, then the element is off, period. Current flows in a loop, so needs both an in and an out leg (in vs. out is a little ambiguous with AC.) SW4 actually causes one leg of the heater supply to switch between a hot leg and neutral, so switches the voltage across the element from 240V to 120V.

Cutting the voltage to the element in half, cuts the power by 4X. Power is equal to V^2 / R. So at 120V the max power to the element is 5500W / 4 = 1375W

Brew on

 

[Bobby_M]

Looks like SW4 turns on/off the second leg to the element converting it from 240 to 120v.

Looking at the DSPR you can control power or set it to hold at a temp. I don't see where you can do both though. He will want the RIMS element to run at 50% power while maintaining mash temp.

I understand the intent. I use a 240/120v switch for eBIAB but only because it's a traditional PID. The EZBOIL is much less likely to let the rims overheat when running 240v as long as the probe is properly located on the rims exit end.

 

[Bobby_M]

Dbl post. Crappy app.

 

[CoalCracker]

So what is the consensus? The ezboil or the device in the schematic? They are fairly price competitive.

Also, I think i'd like a switch added to it so that it's not live as soon as I plug the panel in. I'd like the ability to turn it on and off.

Other than that, it looks great to me. Probably start ordering the parts this week.

 

[augiedoggy]

So what is the consensus? The ezboil or the device in the schematic? They are fairly price competitive.

Also, I think i'd like a switch added to it so that it's not live as soon as I plug the panel in. I'd like the ability to turn it on and off.

Other than that, it looks great to me. Probably start ordering the parts this week.

I cant believe im saying this but the Auber ezboil is the better choice... I just bought one myself for my BK

another option that I took was to go with a long 240v cartridge heater (2000w) so the liquid has a longer and more even contact time in one pass to allow the liquid to be consistently (and more gently with lower watt density which is why many put 120v/240v switches in to obtain) heated by the time it exits the how end... similiar to the way a herms coil works.

I used a 36" long cartridge heater with 1" stainless pipe and camlock fittings for easy teardown and cleaning if needed. they come in many different wattages and lengths. built the whole tube with heater for under $100.

 

[CoalCracker]

Disregard my last post. I misread it as saying DSPR1, which is the manual controlled PWM. The DSPR120 is the EZboil..

 

[CoalCracker]

Also, looking at parts, Auber has a Volt Meter. DV-100. That would be nice to be able to visually see what voltage is flowing. In my limited design knowledge, I'd add that to the Neutral and the hot leg coming out of the r30a reay at the COM connection?

Also, instead of using a 30a switch, can you use a contactor and then use a 3 position 2 NO switch?

240 off 120

 

[doug293cz]

So what is the consensus? The ezboil or the device in the schematic? They are fairly price competitive.

Also, I think i'd like a switch added to it so that it's not live as soon as I plug the panel in. I'd like the ability to turn it on and off.

Other than that, it looks great to me. Probably start ordering the parts this week.

Disregard my last post. I misread it as saying DSPR1, which is the manual controlled PWM. The DSPR120 is the EZboil..

You had me scratching my head there for a couple of minutes.

Brew on

 

[CoalCracker]

I have a case of the Mondays... lol

 

[JimboVorlaufski]

Remember at half the voltage youre at 1/4 the power. You might not be happy with your 5500W Camco putting out 1375W. Id try it first before putting time and money into the build.

 

[CoalCracker]

When I am running on 120v, I'll be supplementing with the power burner on my gas stove. I currently run a 2000w 120v on a BIAB build with the stove and I get a very strong boil, I have to turn the stove down a bit. I think I'll be fine with the 1375.

The majority of the time, I'll be running on 240v. However, I'd like the option to be able to use this inside the house as well.

 

[doug293cz]

Also, looking at parts, Auber has a Volt Meter. DV-100. That would be nice to be able to visually see what voltage is flowing. In my limited design knowledge, I'd add that to the Neutral and the hot leg coming out of the r30a reay at the COM connection?

Also, instead of using a 30a switch, can you use a contactor and then use a 3 position 2 NO switch?

240 off 120

Ok, here's how to wire in the DV-100 volt meter:



Here's an older design (before the DSPR120 became available) that shows how to do 120V/240V switching using a three position switch (on-off-on) and two contactors. There is a potential nasty failure mode if you switch very quickly between the two on positions of the three position switch. The contactor being turned on could engage before the contactor being turned off releases, thus shorting one of the hot lines to neutral. Not good I would definitely recommend the method in the first design, as it is doesn't have this potential failure mode.



It's also possible to do the switching with a three position (on-off-on) 3-phase transfer switch. I don't have a design for that put together, but could do so if you are interested.

Brew on

 

[doug293cz]

...

Also, I think i'd like a switch added to it so that it's not live as soon as I plug the panel in. I'd like the ability to turn it on and off.

Other than that, it looks great to me. Probably start ordering the parts this week.

The only thing live when plugged in is the DSPR120 (as long as all the switches are off.) You can certainly add a switch for the DSPR120, but really, why is it necessary? If you are interested in a "master" power switch, that can be added, as either a Leviton 3032 toggle, or a contactor with a control switch. If you really want to prevent some possible "oopses", you could add a safe start circuit which won't let the panel power on unless all of the switches are off.

Brew on

 

[CoalCracker]

Thanks, No need for a transfer switch.. haha. I was just looking for an option so I don't have a large household light switch on the panel. Everything else looks good. Thanks for all of the help with this.

 

[doug293cz]

Thanks, No need for a transfer switch.. haha. I was just looking for an option so I don't have a large household light switch on the panel.

Understand the sentiment. Some brewers want cheap/simple more than anything else, others prefer aesthetics/elegance. Neither choice is wrong, as long as what you do is safe.

Everything else looks good. Thanks for all of the help with this.

You are welcome. I enjoy doing it, and as a retired engineer, need something technical to keep my mind sharp.

Brew on

 

[CoalCracker]

First order made! All indicators and switches. Purchased the enclosure as well. Next payday, I'll order the rest for the panel.

Then the expensive stuff, pump, RIMS tube, and elements.