switcing from 4 conductor supply to 3 conductor supply

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BrewinBigD

BrewinBigD

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now i should know this, but wanna make sure im corect in my thinking.

I built my E brewery to match my garages wiring and the circut im on is wired for 2 hot 1 N and 1 g, so inside the controller it is wired as such.

i am moving to a new home and will be building the brewery in my basement and using my clothes dryer circut, wired 3 prong with 2 hot, 1 G.
i know that in all household panels the G and neutral meet andare wired back to the pole ofer the same conductor, so shoulndt i be able to eliminate my N wire inside the controller and jump it to the internal ground and then just wire a 3 prong connector to my cord, or should i run a dedicated neutral from the dryer outlet back to the panel and replace said outlet with a 4 prong?
 
If you're drawing 120V for pumps or whatever, switch to a neutral and ground. If you're only running 240V elements, you're fine with two hots and a ground.
 
BrewinBigD said:
now i should know this, but wanna make sure im corect in my thinking.

I built my E brewery to match my garages wiring and the circut im on is wired for 2 hot 1 N and 1 g, so inside the controller it is wired as such.

i am moving to a new home and will be building the brewery in my basement and using my clothes dryer circut, wired 3 prong with 2 hot, 1 G.
i know that in all household panels the G and neutral meet andare wired back to the pole ofer the same conductor, so shoulndt i be able to eliminate my N wire inside the controller and jump it to the internal ground and then just wire a 3 prong connector to my cord, or should i run a dedicated neutral from the dryer outlet back to the panel and replace said outlet with a 4 prong?
Click to expand...


These days it is a Code violation to use common ground/neutral if you're doing a 120/240V circuit.

iBrewR has it right. If you need 120/240V then replace the 2 wire w/ground cable with 3 wire w/ground and put in the four terminal receptacle. If the system is 240V only then what you have is fine.
 
It's not a code violation if it's an existing circuit, which is why you are not required to rewire a 3 wire dryer outlet when buying & installing a new dryer. Instead you just buy a 3 wire pig tail and tie the ground & neutral together inside the dryer.

And the same would be true for your brewery controller - tie the neutral & ground together and you will be fine for all 240V or a mix of 120V & 240V because you are plugging into an EXISTING dryer outlet. The down side is you can't use GFI with 3 wire and a mix of 120V & 240V components.

But installing a new dryer outlet circuit has to be wired to code to be legal, which means it is supposed to be 4 wire even in older houses.
 
Yeah, existing circuit is still legal. But, unless the basement is finished and it's a real hassle I'd still change it to a four wire system.
 
I see no issue with just tying the N and G together inside the controller. No code violation there as it is considered an appliance. Rewiring the whole circuit in the basement would be a PITA due to the location of my setup in regards to the panel. I would just add a sub panel for the brewery but it would take some rearranging of load in the main panel to keep both sides balanced.
The only thing I worry about with using the 3 wire setup is causing a ' hot' ground while using my pumps. Never known this to be an issue before but it can happen.
I have some time before ill be able to rebuild the brewery anyway so it'll be a matter of running the options through my mind before I nail it down.
Thanks for the input guys...
 
thargrav said:
It's not a code violation if it's an existing circuit, which is why you are not required to rewire a 3 wire dryer outlet when buying & installing a new dryer. Instead you just buy a 3 wire pig tail and tie the ground & neutral together inside the dryer.

And the same would be true for your brewery controller - tie the neutral & ground together and you will be fine for all 240V or a mix of 120V & 240V because you are plugging into an EXISTING dryer outlet. The down side is you can't use GFI with 3 wire and a mix of 120V & 240V components.

But installing a new dryer outlet circuit has to be wired to code to be legal, which means it is supposed to be 4 wire even in older houses.
Click to expand...
/\ - This is absolutely correct with one exception. The brewery can be GFCI protected. This can be acomplished by using a homedepot.com - Spa Panel and setting it up as a plug in device using the 3 wire dryer outlet.

The dryer outlet is already protected with a 30A breaker. The Spa Panel provides the GFCI protection. This is how it can be done:

power-panel-6.jpg



Hope this helps.

P-J
 
P-J said:
/\ - This is absolutely correct with one exception. The brewery can be GFCI protected. This can be acomplished by using a homedepot.com - Spa Panel and setting it up as a plug in device using the 3 wire dryer outlet.

The dryer outlet is already protected with a 30A breaker. The Spa Panel provides the GFCI protection. This is how it can be done:

power-panel-6.jpg



Hope this helps.

P-J
Click to expand...

This spa panel can be misleading - the GFI protection inside the panel will protect everything past the device (the spa or your home brewery), but the panel itself & incoming power connections are unprotected.

And because of this, mount them side by side and I don't see much gain. But knowing this I can see how this spa panel would make a great brew controller housing with the GFI protection serving as the main incoming disconnect. You would still be protecting your brew pot and any hot wiring past the disconnect.

But my opinion of all of this is still the same. Make sure you have good solid grounds and you follow sound wiring practices and you disconnect the main power before working on anything and you don't need GFI.
 
Right, but for that same precaution is why those circuits are now 4-wire.
 
P-J said:
/\ - This is absolutely correct with one exception. The brewery can be GFCI protected. This can be acomplished by using a homedepot.com - Spa Panel and setting it up as a plug in device using the 3 wire dryer outlet.

The dryer outlet is already protected with a 30A breaker. The Spa Panel provides the GFCI protection. This is how it can be done:

power-panel-6.jpg



Hope this helps.

P-J
Click to expand...

PJ,
I never thought of this my current setup isn't GFI protected, but for
he new setup I think its a wise idea. And it will also give me an opportunity to wire a normally open EStop. I plan on doing this by going from 1 power line through a pair of 1Mohm resistors ( I have to look @ your easy 1 PID controller schematic to verify that value) and then to the switch which will close to ground when activated. Genius!!!
 
BrewinBigD said:
PJ,
I never thought of this my current setup isn't GFI protected, but for
the new setup I think its a wise idea. And it will also give me an opportunity to wire a normally open EStop. I plan on doing this by going from 1 power line through a pair of 1Mohm resistors ( I have to look @ your easy 1 PID controller schematic to verify that value) and then to the switch which will close to ground when activated. Genius!!!
Click to expand...
Thanks. If I can help you with any different ideas, diagram changes or parts source info, please let me know.

Oh: The resistors are 1K ohm resistors - 2 wired in series. This gives 0.06A leakage current to ground. That is all it takes to trip the GFCI.

Wishing you the best.

P-J
 
So I'm going to wire this right next to my controller eliminating my internal power on/off switch, and just using the "test" button as an Estop. It works. the same as wiring in a remote switch so ill save time and money!
 
What prevents someone from flipping the GFI breaker back on while you are working on something? You still need a mechanical disconnect switch on the panel to be safe.
 
thargrav said:
What prevents someone from flipping the GFI breaker back on while you are working on something? You still need a mechanical disconnect switch on the panel to be safe.
Click to expand...

Another possibility...

Latching circuit for master arming/ON with a form of E-stop included. Prevents inadvertent energization on power loss and the type of situation thargrav mentions.

I think would be better if it was done with low voltage control but it still serves the purpose.

latching_estop.jpg
 
I understand your logic but every industry has "lock-out, tag-out" procedures in place because electrical safety devices that do not have a mechanical disconnect have proven unsafe & killed people.

Install a mechanical disconnect like a incoming breaker or power switch so that you know the power is disconnected when you are working on your equipment!
 
thargrav said:
What prevents someone from flipping the GFI breaker back on while you are working on something? You still need a mechanical disconnect switch on the panel to be safe.
Click to expand...

What prevents this is having the GFI breaker wires as part of the brewery control panel, and since im the only one who brews im not too worried about it.
 
thargrav said:
I understand your logic but every industry has "lock-out, tag-out" procedures in place because electrical safety devices that do not have a mechanical disconnect have proven unsafe & killed people.

Install a mechanical disconnect like a incoming breaker or power switch so that you know the power is disconnected when you are working on your equipment!
Click to expand...

and my set up is not hard wired to the home. it will plug into the dryer outlet while brewing, and will be disconnected all other times.
 
BrewinBigD said:
What prevents this is having the GFI breaker wires as part of the brewery control panel, and since im the only one who brews im not too worried about it.
Click to expand...

Absolutely nothing & I even suggested using the Home Depot GFI SPA Wiring Panel as a home brewery control panel in an earlier post. From the picture, there seems to be plenty of space inside the panel.
 
For myself, the appeal of a great big switch that I can smack immediately without having to hunt for it is a good thing. I have had to use e stop switches in emergency situations with power carts on the flight line. Your brain doesn't work clearly enough under a panic situation to flip four or five switches to kill power, just go for the red button!

We had a power cart that liked to spike the voltage way over its rating, causing electrical components to release the smoke!
 
Sure, that's what I included in my rendition of the drawing and that P-J and others have done in a different way by shunting current to ground to trip the GFCI.

In hindsight though what thargrav suggests is more like a mechanical master disconnect, someplace you can see it or at least with a lockout capability. Certainly unplugging the control system would fit this as long as you can observe that someone hasn't done you a "favor" and plugged it back in. :)
 

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