The Great Bottle Opener Giveaway

Home Brew Forums > Home Brewing Beer > DIY Projects > 240V 3 prong vs 4 prong

Reply
 
LinkBack Thread Tools
Old 03-15-2010, 05:01 PM   #1
jfkriege
Feedback Score: 0 reviews
Recipes 
 
Join Date: Aug 2009
Location: Bloomington, IN
Posts: 419
Liked 1 Times on 1 Posts

Default 240V 3 prong vs 4 prong

I am currently building an electric rig. It will have a 240V feed for the element as well as two pumps (120V) and the PID controller.

I have a 3 prong outlet in the house already. Is there a real advantage to either? Is it wrong to use either as long as there is GFCI protection on the line?

I am wanting to understand this more.

__________________
jfkriege is offline
 
Reply With Quote Quick reply to this message
Old 03-15-2010, 05:03 PM   #2
willynilly
Feedback Score: 0 reviews
Recipes 
 
Join Date: Feb 2010
Location: Avon
Posts: 728
Liked 5 Times on 5 Posts

Default

With a three prong, you will be missing the neutral for the 120VAC stuff

__________________
willynilly is offline
 
Reply With Quote Quick reply to this message
Old 03-15-2010, 05:04 PM   #3
jfkriege
Feedback Score: 0 reviews
Recipes 
 
Join Date: Aug 2009
Location: Bloomington, IN
Posts: 419
Liked 1 Times on 1 Posts

Default

I thought the ground and neutral were tied together at the box and so functioned as either.

__________________
jfkriege is offline
 
Reply With Quote Quick reply to this message
Old 03-15-2010, 05:04 PM   #4
diatonic
HBT_SUPPORTER.png
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jan 2009
Location: Boise, ID
Posts: 713
Liked 10 Times on 8 Posts
Likes Given: 9

Default

If you want to run 120 loads you'll need the 4 prong. I'm running separate 110v & 220v in to my panel so that I can use it where 220v is unavailable, but that may not be a concern for you.

__________________

.:diatonic:.

1° - Simple Cider (2/15/2014) - Saison Mead (6/26/2014) - En Perpetuum (Belgian sour base) (7/3/2014)
2° - Nuthin
Aging in a wine barrel - En Perpetuum—Solera (1/23/2011)
Kegs - May the Schwarz-Bier with you (2/9/2014) — Test Depth American Stout (8/29/2013), Big Red Imperial Red IPA (1/19/2014)

My brew rig is pretty much done :)
You should follow me on Twitter - My Brew Logs

diatonic is offline
 
Reply With Quote Quick reply to this message
Old 03-15-2010, 05:06 PM   #5
diatonic
HBT_SUPPORTER.png
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jan 2009
Location: Boise, ID
Posts: 713
Liked 10 Times on 8 Posts
Likes Given: 9

Default

Quote:
Originally Posted by jfkriege View Post
I thought the ground and neutral were tied together at the box and so functioned as either.
Ground and neutral should not be tied together at the box. If you're using GFCI, and you should, then that would present a big problem designing current to go to ground... since that is what causes gfci breakers to trip.

EDIT: This might not be correct, and I'm not an electrician
__________________

.:diatonic:.

1° - Simple Cider (2/15/2014) - Saison Mead (6/26/2014) - En Perpetuum (Belgian sour base) (7/3/2014)
2° - Nuthin
Aging in a wine barrel - En Perpetuum—Solera (1/23/2011)
Kegs - May the Schwarz-Bier with you (2/9/2014) — Test Depth American Stout (8/29/2013), Big Red Imperial Red IPA (1/19/2014)

My brew rig is pretty much done :)
You should follow me on Twitter - My Brew Logs


Last edited by diatonic; 03-15-2010 at 07:53 PM. Reason: Not sure if my statement is correct
diatonic is offline
 
Reply With Quote Quick reply to this message
Old 03-15-2010, 05:07 PM   #6
willynilly
Feedback Score: 0 reviews
Recipes 
 
Join Date: Feb 2010
Location: Avon
Posts: 728
Liked 5 Times on 5 Posts

Default

Quote:
Originally Posted by jfkriege View Post
I thought the ground and neutral were tied together at the box and so functioned as either.
You are right, ground and neutrals are common in the panel, they are on the same bars... but


You cannot run a ground wire as a neutral, and a ground in your system. Otherwise, there would be no neutrals in your home. The electic guys are going to be all over this, any bet on how long?
__________________

Last edited by willynilly; 03-15-2010 at 05:11 PM.
willynilly is offline
 
Reply With Quote Quick reply to this message
Old 03-15-2010, 05:22 PM   #7
jfkriege
Feedback Score: 0 reviews
Recipes 
 
Join Date: Aug 2009
Location: Bloomington, IN
Posts: 419
Liked 1 Times on 1 Posts

Default

I hope the electric guys are not all over this. I asked because I wanted to know before hand and not do something stupid. I understand more now.

I will wait until I can get a 4 prong circuit installed before I do anything, or I will run a second 120V line into the box in order to power the pumps and the PID.

Somewhat related: If I have a 4 wire 30A circuit, what is the amp rating on the 120V lines if they are isolated and not used for 240V (e.g. if I wanted to run 2 smaller 120V heating elements)?

__________________
jfkriege is offline
 
Reply With Quote Quick reply to this message
Old 03-15-2010, 05:27 PM   #8
willynilly
Feedback Score: 0 reviews
Recipes 
 
Join Date: Feb 2010
Location: Avon
Posts: 728
Liked 5 Times on 5 Posts

Default

30A?

I mean your breaker and your wiring will handle 30A on a single leg...

I dont see why it wouldnt

Just make sure that your total draw on BOTH legs doenst exceed 30A too

__________________
willynilly is offline
 
Reply With Quote Quick reply to this message
Old 03-15-2010, 05:32 PM   #9
jfkriege
Feedback Score: 0 reviews
Recipes 
 
Join Date: Aug 2009
Location: Bloomington, IN
Posts: 419
Liked 1 Times on 1 Posts

Default

The question in my mind is about the neutral.

If I have 15A running through one 120-Neutral and 15A running through the other 120-Neutral, am I running a total of 30A down the neutral line and therefore at my limit for a 30A circuit? Does that even make sense?

__________________
jfkriege is offline
 
Reply With Quote Quick reply to this message
Old 03-15-2010, 05:35 PM   #10
willynilly
Feedback Score: 0 reviews
Recipes 
 
Join Date: Feb 2010
Location: Avon
Posts: 728
Liked 5 Times on 5 Posts

Default

I am officially lost.

As long as it is wired properly, what matters is how much load you have on the circuit, not what lines the load is on.

__________________
willynilly is offline
 
Reply With Quote Quick reply to this message
Reply


Quick Reply
Message:
Options
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Ranco wiring 240V beer_master DIY Projects 4 07-04-2011 12:27 PM
240v Switch Options illin8 DIY Projects 14 03-07-2010 07:12 PM
3 Pos 240v Switch illin8 DIY Projects 8 05-20-2009 02:07 AM
New House & 240V illin8 Equipment/Sanitation 16 05-07-2009 02:39 PM
Replacing 2-prong cord with grounded cord sphericalcamel Equipment/Sanitation 3 07-04-2007 03:31 PM