220V Single Vessel RIMS Build - Help with wiring PID Controller w-110v GFCI

[brucebeernut]

I'm finally back to brewing and the first thing I’m getting away from my propane burner and going all electric BIAB.

Starting with a Bayou Classic 16g stainless kettle, I'm going 220V so I can use a 6500W element for quick boils and PID for recirculating mash temperature control.

I was inspired by You Tuber “Barley and Hops Brewing” and his builds of simple PID controllers used both in brewing beer and distilling. Unfortunately, he no longer replies to comments on his videos or answers emails. I hope his health is holding up. Search for "BUILDING A 240 VOLT 20 AMP PID CONTROLLER STEP BY STEP PART 1" and... PART 2

I'm adding 110V GCFI to the control box and need an extra set of eyes on my wiring, schematic attached.
I humbly ask for your input! I can provide the parts and pieces for those who may be considering a similar project.
Thanks in advance for your help!

 

[Bobby_M]

Are you not planning to run the whole controller on a GFCI protected breaker?

 

[doug293cz]

Why do you have a neutral wire going to the element? There is nothing to connect it to on the element. Why is your volt/amp meter measuring only across one hot and neutral (where you will only measure ~120V)? You should really have it connected to both hots if you want to monitor element power.

With one hot totally unswitched, your element will be energized whenever the panel is connected to power. This is not a very safe design. You should have a mechanical disconnect in the panel for both hots.

As Bobby mentioned, you should have a GFCi for the power incoming to the panel. With this panel input protection, any 120V outlets from the panel will have GFCI protection.

Brew on

 

[brucebeernut]

220vac input is a dedicated outlet in the main breaker box to a dryer 14-50P receptacle. The breaker is GFCI
@doug293cz, As I understand it, only one hot lead needs to be 'looped' for amperage draw monitoring?
Will the element be energized with 3 of the 4 leads connected? Pin 2 on the SSR won't be energized until told by the PID.
Easy enough to leave out the neutral wire to the element. I'm using a 4wire L14-30P/L14-30R extension cord cut in two for panel-adapter to controller and controller to element.

 

[doug293cz]

As I understand it, only one hot lead needs to be 'looped' for amperage draw monitoring?

Yes, you should only run one of the hots thru the current sensing coil of the volt/amp meter. If you ran both, then the currents in opposite directions would cancel each other out, and you would always read 0 - unless you had a fault that caused unbalanced currents to flow. In fact this is how GFCIs work - all the current carrying wires are passed thru the current sensing coil, and the result should always be 0. If it is not 0, then current is flowing somewhere it shouldn't, so the control circuit in the GFCI trips the breaker. It only takes 5mA of current imbalance to cause a trip.

Will the element be energized with 3 of the 4 leads connected? Pin 2 on the SSR won't be energized until told by the PID.

Yes, each hot wire provides 120V potential referenced to ground/neutral. You only need to switch one to modulate power, since current needs a complete loop to flow from source to load back to source. Break the loop anywhere and current flow stops. Since power equals current times voltage, if current is 0, power is 0, no matter what the voltage is.

But, if you have an unswitched hot line going to your element, then the element will have at least 120V potential on it at all times, even tho no current if flowing (until you touch something you shouldn't and provide a return current path.) This can represent a shock hazard to you if you end up with a compromised connection, wire insulation, etc.

Brew on

 

[brucebeernut]

Thank You!
So include a STDP with 40a rating? 6500 watt / 220vac = ~30amp potential max draw?

 

[doug293cz]

Thank You!
So include a STDP with 40a rating? 6500 watt / 220vac = ~30amp potential max draw?

Yes, you can use a switch like the Leviton 3032, or a contactor controlled by a more aesthetically pleasing switch. Why are you using a 6500W element? Most brewers find 5500W more than adequate. 6500W on a 240V circuit will draw ~27A, which is awfully close to the 30A limit. A 5500W element only draws 23A max, so has more margin.

Also, I wouldn't use one of George's controller design. They are workable, but they don't have safety features I consider critical, nor are they designed to prevent the more common errors that operators may make.

Brew on

 

[brucebeernut]

Again, THANKS! I'll add the STDP switch...
I've already purchased a 6500W element. If it proves too much, I'll change it up!

 

[Bobby_M]

220vac input is a dedicated outlet in the main breaker box to a dryer 14-50P receptacle. The breaker is GFCI
@doug293cz, As I understand it, only one hot lead needs to be 'looped' for amperage draw monitoring?
Will the element be energized with 3 of the 4 leads connected? Pin 2 on the SSR won't be energized until told by the PID.
Easy enough to leave out the neutral wire to the element. I'm using a 4wire L14-30P/L14-30R extension cord cut in two for panel-adapter to controller and controller to element.

If the breaker is GFCI, no need to add the extra GFCI on the 120v outlet but I suppose there's no hard either.

You may want to move the current coil to the black wire where it comes in to the panel because it will show the total current draw, including anything plugged in to the 120v outlet.

A very nice upgrade either now or in the future would be to replace the Inkbird PID with the Auber DSPR-120 module. Probably an extra $30, but vastly improved functionality and user interface.

 

[doug293cz]

You may want to move the current coil to the black wire where it comes in to the panel because it will show the total current draw, including anything plugged in to the 120v outlet.

Where to put the current sensing coil depends on just what information you are interested in. If you want to know the total power draw of everything powered thru the panel, then you need place the coil on a hot that feeds both the 240V and 120V loads, as Bobby notes above. If you only want to know how much current/power is going to the element, then you want the sensing coil where you have it shown already.

Brew on

 

[Bobby_M]

Where to put the current sensing coil depends on just what information you are interested in. If you want to know the total power draw of everything powered thru the panel, then you need place the coil on a hot that feeds both the 240V and 120V loads, as Bobby notes above. If you only want to know how much current/power is going to the element, then you want the sensing coil where you have it shown already.

Brew on

It seems to me that George's idea was to use it as the "element is firing" indicator. Frankly, I prefer a big red 22mm LED for that roll. I need a periphery indication without having to read a number.

 

[doug293cz]

It seems to me that George's idea was to use it as the "element is firing" indicator. Frankly, I prefer a big red 22mm LED for that roll. I need a periphery indication without having to read a number.

I agree. I always put both an "Element Enabled" (usually a lighted switch) and an "Element Firing" (wired in parallel with the element) LEDs in my designs.

Brew on