Just Moved - seeking advice on adapting my setup

[IslandLizard]

It looks the trigger current for class A GFCIs is 5mA.
So a resistor with a value of 120V/5mA = 24kΩ from one of the hot poles (~120V nom.) to ground should trigger the GFCI.

However 24 kΩ (5% or 10% tolerance) is not a common value, 22 kΩ and 27 kΩ are.
So a common 22 kΩ (5% or 10% tolerance) resistor should do it with a trigger current of 5.5 mA at 120V.

Power dissipation is V * I = 120V * 5.5mA = 0.66 Watt. Now since it's supposed to be on 'load' for only a fraction of a second, 1/4 watt should suffice. As long as the circuit works as it should and shuts off fast.
Keeping the button down if it doesn't work will fry that 1/4 watt resistor in short time. Use a 1/2 Watt or 1 Watt resistor if you plan to do this.

How GFCIs work.

 

[johnnybrews12]

Ok, great info @doug293cz and @IslandLizard - thank you again. I'll be moving forward with this build asap. Quick question, does anybody know where I can source some 240v 20a switches? The ones from my old control box were rated for 120v and I had them switching a contactor. The only thing I see online are switches like these. I was hoping to be able to find something more like this but with the appropriate rating.

 

[BeardedBrews]

Do they need to be 20a?

Above 10a or so you end up in a heavier duty switch like this:
https://www.amazon.com/dp/B07L7SHLLD/ref=cm_sw_r_cp_apa_i_7gvTCb41EDHWW

Or you use a Leviton light switch

 

[johnnybrews12]

Do they need to be 20a?

Above 10a or so you end up in a heavier duty switch like this:
https://www.amazon.com/dp/B07L7SHLLD/ref=cm_sw_r_cp_apa_i_7gvTCb41EDHWW

Or you use a Leviton light switch

I have a Leviton light switch - that is what served as my main power switch for my old box. I'd like to use components I have on hand and I have two switches that look like they're rated for 10 amps. Can I switch 1 of my 2 hot legs with my switch that's rated for 10a and effectively kill power to the element need be? Does that 1 hot leg see the same current as both legs together when running a 3500w element? Would that not work?

 

[BeardedBrews]

Unfortunately both legs see the same amps, you need a fully rated switch either way.

You could use those switches with a contactor which wouldn't be too expensive...

 

[johnnybrews12]

You could use those switches with a contactor which wouldn't be too expensive...

I have a contactor from my last set up but I was under the impression you need a neutral for that to work, right?

 

[doug293cz]

I have a contactor from my last set up but I was under the impression you need a neutral for that to work, right?

You don't need a neutral for a contactor unless it has a 120V coil, in which case the coil is wired to one of the hots (switched) and neutral. If the coil is 240V then the coil is wired to both hots, with one, or both, hots switched. Best practice is to switch both hots with a double pole switch. Some contactors have replaceable coils, but it may be just as cheap to replace the entire contactor (depending on the pricing you can get for a loose coil, and the risk of getting an incompatible coil.)

Brew on

 

[BeardedBrews]

You could use a 240v coil contactor.
Packard C230C 2 Pole 30 Amp Contactor 208/240 Volt Coil Contactor https://www.amazon.com/dp/B004YW5CWQ/ref=cm_sw_r_cp_apa_i_X8vTCbV8XHJJX


You could also use a 5v version and then use a physical switch or turn it on and off with the rPi
Yeeco 30A High Current Relay Output Relay Control Module Power Switch Normally Open Normally Closed 5V DC Electric Current Amp Transfer for Cooler/heater Cooler Heater Refit Water Heater Control https://www.amazon.com/dp/B00R7TTSMI/ref=cm_sw_r_cp_apa_i_x-vTCb9XWG0EN

 

[johnnybrews12]

Great, wasn't aware of 240v coil contactors. If I use a contactor, does that mean that my switches won't see the ~16 amps of current my element is drawing?

 

[BeardedBrews]

Yup, it only sees enough current to turn on the contactor.

 

[doug293cz]

Great, wasn't aware of 240v coil contactors. If I use a contactor, does that mean that my switches won't see the ~16 amps of current my element is drawing?

Yes, the contactor coils usually take less than 0.1A. It's the contacts in the contactor that carry the high current. This is why they are used (among other reasons.)

Brew on

 

[doug293cz]

I have made an important update to this post in the thread. It affects how the pigtail connection affects the correct operation of the "Test" button on the GFCI. Please go back and read the new information.

Brew on

 

[johnnybrews12]

@doug293cz thank you for the clarification. If you were in my shoes, would you use that 220v outlet in combination with the spa panel gfci and a 3500w element OR would you use 2 1650w elements that get their power from 2 separate 120v 20a circuits located in my kitchen.

I did some measuring and found that if I want to brew in the kitchen area (or even on my deck located next to the kitchen) using that 220v outlet I'd need a ~60ft extension cord. From my understanding, the voltage drop would be relatively negligible using 10g conductor BUT as I've seen online that length and type extension cord is quite pricey...

EDIT: I'm not only looking at this alternative option from a price standpoint but from a safety standpoint as well.

 

[khannon]

maybe spend a few $$ and go buy a fire extinguisher that covers electric, keep it on hand, and use it if you manage to let the smoke out of anything?

[edit] as for reading further, you might save some by building your own "extension" should only be a plug, some 10g romex with an appropriate number of strands, an outlet box and an outlet.. It might be a little stiffer, but will serve you well and probably save you a few pennies.. If you are unsure, you can take the advice I give my kids when they go to the hardware store.. "Walk in, find the guy with the longest greyest beard you can, and ask all your questions.."

 

[BeardedBrews]

I would use the 220 outlet and the kettle you already have built and just put a box fan in the window when you brew.

Way easier to control boil overs with electric, your controller plan is fundamentally safe, the outlet has ample power.

Brew, clean up, done

[emoji482]

 

[doug293cz]

maybe spend a few $$ and go buy a fire extinguisher that covers electric, keep it on hand, and use it if you manage to let the smoke out of anything?

[edit] as for reading further, you might save some by building your own "extension" should only be a plug, some 10g romex with an appropriate number of strands, an outlet box and an outlet.. It might be a little stiffer, but will serve you well and probably save you a few pennies.. If you are unsure, you can take the advice I give my kids when they go to the hardware store.. "Walk in, find the guy with the longest greyest beard you can, and ask all your questions.."

Romex should not be used for an extension cord. It is not designed for conditions that involve regular flexing. It has solid core rather than stranded wire. Also, the insulation isn't rated for wet conditions, and I've never seen a dry brewery.

Brew on

 

[doug293cz]

@doug293cz thank you for the clarification. If you were in my shoes, would you use that 220v outlet in combination with the spa panel gfci and a 3500w element OR would you use 2 1650w elements that get their power from 2 separate 120v 20a circuits located in my kitchen.

I did some measuring and found that if I want to brew in the kitchen area (or even on my deck located next to the kitchen) using that 220v outlet I'd need a ~60ft extension cord. From my understanding, the voltage drop would be relatively negligible using 10g conductor BUT as I've seen online that length and type extension cord is quite pricey...

EDIT: I'm not only looking at this alternative option from a price standpoint but from a safety standpoint as well.

I'd use the spa panel, but that's just my preference.

Brew on

 

[IslandLizard]

I think choosing the right brewing location is very important. Also depends on how many times you brew.

Brewing outside will likely draw attention from your neighbors, thus the landlord and if there is one, the HOA. Keep that in mind.
The more inconspicuously you can brew, the better, IMO.

I like the kitchen for brewing 5 or 10 gallon batches, everything is handy and fairly nearby. I stick a box fan in the upper window, right behind the kettle. Zero-condensation.
I mill outside of course.

 

[pullapint]

Hey all,

I just moved into a new apartment (renting). My last apartment had easy access to a 30a 240v dryer plug. This new apartment, not so much. I have tried moving my washer dryer unit but it is jammed into a closet and is stacked. No way I'm getting it out.

I found a 3 prong outlet in my bedroom that I assume is for an air conditioning unit. After checking it out, I found that it has 2 hot legs going to 2 separate 20a breakers. Measuring across the hots I get 240v.

My system is a 15gal EBIAB with a 3500w (it actually may be 4500w but I cannot remember for sure at the moment, will have to look into it) heating element. At the old apartment, I ran a plug from the dryer outlet to a spa panel/gfi and then to my control box (4 wire configuration H-H-N-G).

What are my options here? Can I do anything with the air conditioning outlet? Am I poopy outta luck? Bite the bullet and start designing a new system that uses 2 elements and 2 outlets on different 120v circuits? That would be the last thing I'd want to do because ...money. I've been racking my brain over this for the past week at this point.

With my stacking washer/dryer, there's a panel going up at an angle, "behind" the washer lid. You should be able to remove that and get access too the outlet.

 

[johnnybrews12]

@pullapint I just got home from work and pulled that panel off. I'm not sure if I did it right, maybe I'm supposed to take the sub panel off too? See the attached picture to get an idea of what I'm working with.

 

[pullapint]

Mine didn't have the 2nd panel that you seem to have. Mine opened to the wall behind the washer/dryer with the outlet, water and vent hose.
I'd take off that panel too or try to peek around it.

 

[johnnybrews12]

Mine didn't have the 2nd panel that you seem to have. Mine opened to the wall behind the washer/dryer with the outlet, water and vent hose.
I'd take off that panel too or try to peek around it.

Took it off and there was no access to the wall behind it. I can see the wall in the original picture I sent but can't see the outlet. Oh well, looks like I'll have to go with the original plan of using the 220v outlet in my bedroom. Thanks for the suggestion though, I appreciate it.

 

[pullapint]

You're welcome. There's gotta be at least a 110v back there for the washer, but maybe you have a gas dryer. Good luck.

 

[johnnybrews12]

You could use a 240v coil contactor.
Packard C230C 2 Pole 30 Amp Contactor 208/240 Volt Coil Contactor https://www.amazon.com/dp/B004YW5CWQ/ref=cm_sw_r_cp_apa_i_X8vTCbV8XHJJX


You could also use a 5v version and then use a physical switch or turn it on and off with the rPi
Yeeco 30A High Current Relay Output Relay Control Module Power Switch Normally Open Normally Closed 5V DC Electric Current Amp Transfer for Cooler/heater Cooler Heater Refit Water Heater Control https://www.amazon.com/dp/B00R7TTSMI/ref=cm_sw_r_cp_apa_i_x-vTCb9XWG0EN

Quick question about your suggestion of using a rPi (I'd use an arduino instead because I have some on hand). I had an arduino in my last setup that I was running from my 120v source (hot & neutral connected to an iPhone block converter then to the arduino). If that converter is rated for 240v, do I just run the 2 hots to the input instead of a hot and neutral?

 

[BeardedBrews]

Quick question about your suggestion of using a rPi (I'd use an arduino instead because I have some on hand). I had an arduino in my last setup that I was running from my 120v source (hot & neutral connected to an iPhone block converter then to the arduino). If that converter is rated for 240v, do I just run the 2 hots to the input instead of a hot and neutral?

Yup, exactly. Hot on each leg.

You can probably find a spade connector that will side right onto the charger block prongs

 

[johnnybrews12]

I put together a rough wiring diagram for the control box - it’s attached. If somebody could give it a once-over I’d appreciate it. Please let me know if you need clarification on anything. FYI, the 2 circles with “S” written in them are 12v DC switches.

 

[BeardedBrews]

I put together a rough wiring diagram for the control box - it’s attached. If somebody could give it a once-over I’d appreciate it. Please let me know if you need clarification on anything. FYI, the 2 circles with “S” written in them are 12v DC switches.

There's a 12v switch not tied to the PID, I'm guessing as an element disconnect? Best practice is to use a 2-pole switch so that there are no hot lines leaving the enclosure when you have the switch turned off.

The way you have it drawn that switch would make the element stop getting hot, but it would not protect you from a shock if one of your connections came loose or your element broke in half.

 

[johnnybrews12]

There's a 12v switch not tied to the PID, I'm guessing as an element disconnect? Best practice is to use a 2-pole switch so that there are no hot lines leaving the enclosure when you have the switch turned off.

The way you have it drawn that switch would make the element stop getting hot, but it would not protect you from a shock if one of your connections came loose or your element broke in half.

The goal of that switch is to be able to make the element "cool" in the event that the SSR fails closed, PID overshoots, etc. Wouldn't the spa panel gfci protect me from electrical shock in the instance of a broken element or current leak somewhere else? I wanted to avoid using another 2 pole switch for the element because they're big. The DC switches I looked at on amazon are much smaller and would save me some space. Less space needed = smaller control box = less cost, right?

 

[doug293cz]

The goal of that switch is to be able to make the element "cool" in the event that the SSR fails closed, PID overshoots, etc. Wouldn't the spa panel gfci protect me from electrical shock in the instance of a broken element or current leak somewhere else? I wanted to avoid using another 2 pole switch for the element because they're big. The DC switches I looked at on amazon are much smaller and would save me some space. Less space needed = smaller control box = less cost, right?

The GFCI will prevent you from getting electrocuted, but it may not prevent a shock. I always design with double pole contactors for the element power enable, so that both hots are air gap disconnected when the contactor is not energized.

Brew on

 

[BeardedBrews]

It is helpful to be able to power on the pid, pump, and other components while safely having the element isolated.

I'm all for a smaller control box, but the two-pole element disconnect is probably the one place in the whole box that I wouldn't skip.

You could drop the incoming power relay in favor of the element one if you wanted (I did).