Spike Brewing 12.5 Conical Fermenter Giveaway!

Home Brew Forums > Home Brewing Beer > Electric Brewing > wiring subpanel for future expansion

Reply
 
LinkBack Thread Tools
Old 07-29-2013, 09:48 AM   #11
neo71665
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jun 2013
Location: , Arkansas
Posts: 324
Liked 74 Times on 54 Posts
Likes Given: 40

Default

Piggyback breakers are bad about overheating and tripping before a normal one. If you gotta use it then you gotta.

Also the insulation does melt but take it from an electrician and volunteer firefighter the copper will melt and spark if over loaded. THHN is only a type of insulation and doesn't have any doing with the amp rating of the wire. Wire size, length of run, and item being fed determines what it will carry.

Besides I'd be more interested in the main panel that sub is feeding from. If its only a 200 amp, your house draws 190 amps, that means you only have 10 amps to spare before the main is tripping all the time. You can run 4/0 cable to that sub but its not gonna make everything upstream magically increase to meet current demand.

__________________
neo71665 is offline
 
Reply With Quote Quick reply to this message
Old 07-29-2013, 05:29 PM   #12
whoaru99
Feedback Score: 0 reviews
Recipes 
 
Join Date: Oct 2012
Posts: 1,589
Liked 124 Times on 101 Posts
Likes Given: 16

Default

Quote:
Originally Posted by neo71665 View Post
If its only a 200 amp, your house draws 190 amps, that means you only have 10 amps to spare before the main is tripping all the time. You can run 4/0 cable to that sub but its not gonna make everything upstream magically increase to meet current demand.
True, but it would be pretty rare to have loading that high. If that's a common situation then a single 200A panel probably isn't the right thing to have anyway.
__________________

Primary: Pre-prohibition Lager
Secondary: Russian Imperial Stout
Drinking: Chinook IPA
Drinking: Waldo Lake Amber
Drinking: Edwort's Apfelwein

whoaru99 is offline
 
Reply With Quote Quick reply to this message
Old 07-30-2013, 01:08 AM   #13
twd000
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jul 2010
Location: Tucson
Posts: 410
Liked 3 Times on 3 Posts

Default

This subpanel is being fed with a 50A breaker. The 8/3 feeder cable is Type NM-B

Trying to figure out my options. If I pull out the current double slimline 120V/20A, I will have 2 slots open. I can put the quad breaker in those two slots, but that only gives me a single 120V/20A circuit (in addition to the 240V/30A circuit)

I will never be brewing and woodworking at the same time, so the total load on the 240V stuff is irrelevant. But one of the 120V circuits is used for my beer fridge, and I need to compressor to cycle on as needed, with other small tools and lights on the same circuit if I consolidate to a single 120V/20A circuit.

__________________
twd000 is offline
 
Reply With Quote Quick reply to this message
Old 07-30-2013, 01:37 AM   #14
The10mmKid
HBT_SUPPORTER.png
Feedback Score: 0 reviews
 
The10mmKid's Avatar
Recipes 
 
Join Date: Jul 2013
Location: Home of the Wright Brothers
Posts: 440
Liked 28 Times on 28 Posts
Likes Given: 143

Default

Quote:
Originally Posted by twd000 View Post
This subpanel is being fed with a 50A breaker. The 8/3 feeder cable is Type NM-B
Be careful of that 50A. 8/3-W/G is usually derated to 40A.

From SouthWire.com
"Type NM-B (nonmetallic-sheathed cable) may be used for both exposed and concealed work in normally dry locations at temperatures not to exceed 90°C (with ampacity limited to that for 60°C conductors) as specified in the 2011 National Electrical Code."

OK, you will loose a full size single 20A breaker; opening a spot for the 'quad'.
But you'll gain (2) 20A-single and (1)30A/2-pole.
The outside breakers work independent of any other breaker in the quad.

You can even use two quads if you want.
15A-2x30A-15A and then 20A-2x30A-20A

(This is assuming the quads will fit your panel)

So far, all your options are still on the table. Just be careful loading that 8/3 past 40A. There is some safety factor built in, but any extended duration full load is going to heat up that feed wire.

Be safe,
'da Kid
__________________
The10mmKid is offline
 
Reply With Quote Quick reply to this message
Old 07-30-2013, 02:35 AM   #15
theichthus
HBT_SUPPORTER.png
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jan 2010
Location: Columbus, OH, OH
Posts: 53
Likes Given: 7

Default

A quad and two tandems would be the max number of circuits assuming you only need one 240V circuit. That way you could have six 120V circuits and one 240V.

__________________

"Let him drink, and forget his poverty, and remember his misery no more."

- Proverbs 31:7

theichthus is offline
 
Reply With Quote Quick reply to this message
Old 07-30-2013, 04:01 AM   #16
twd000
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jul 2010
Location: Tucson
Posts: 410
Liked 3 Times on 3 Posts

Default

sweet. sounds like the quad will get me what I need

I'll never get to 40A draw. The woodworking machines have large induction motors that pull a lot of amps on startup then quickly settle down to 6-8 Amps

The largest draw I'll have is running my ULWD element plus the fridge, and that should be under 30 A

__________________
twd000 is offline
 
Reply With Quote Quick reply to this message
Old 07-30-2013, 04:19 PM   #17
neo71665
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jun 2013
Location: , Arkansas
Posts: 324
Liked 74 Times on 54 Posts
Likes Given: 40

Default

Quote:
Originally Posted by whoaru99 View Post
True, but it would be pretty rare to have loading that high. If that's a common situation then a single 200A panel probably isn't the right thing to have anyway.

More common than you think, lowest bidder usually gets the cheapest and barely big enough products to get the house done. Often builders are more than happy to save money everywhere they can.
__________________
neo71665 is offline
 
Reply With Quote Quick reply to this message
Old 08-01-2013, 12:37 PM   #18
whoaru99
Feedback Score: 0 reviews
Recipes 
 
Join Date: Oct 2012
Posts: 1,589
Liked 124 Times on 101 Posts
Likes Given: 16

Default

I understand about lowest bidders but presumably they still have to be built to the spec, NEC, and pass inspection.

__________________

Primary: Pre-prohibition Lager
Secondary: Russian Imperial Stout
Drinking: Chinook IPA
Drinking: Waldo Lake Amber
Drinking: Edwort's Apfelwein

whoaru99 is offline
 
Reply With Quote Quick reply to this message
Old 09-27-2013, 04:52 AM   #19
twd000
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jul 2010
Location: Tucson
Posts: 410
Liked 3 Times on 3 Posts

Default

a longshot followup question: is there such thing as a quad breaker that includes a GFCI, so that I wouldn't have to add a spa panel downstream of this sub-panel?

__________________
twd000 is offline
 
Reply With Quote Quick reply to this message
Old 09-27-2013, 11:58 AM   #20
ChuckO
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
ChuckO's Avatar
Recipes 
 
Join Date: Oct 2008
Location: Keyrock, WV
Posts: 885
Liked 78 Times on 70 Posts
Likes Given: 11

Default

Quote:
Originally Posted by twd000 View Post
a longshot followup question: is there such thing as a quad breaker that includes a GFCI, so that I wouldn't have to add a spa panel downstream of this sub-panel?
Why not put the GFCI upstream? Replace the 50A breaker in the main panel with a 50A GFCI breaker.
__________________
ChuckO 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
How to take the next step - expansion fenrrris Beginners Beer Brewing Forum 13 02-18-2013 10:29 PM
Keezer Collar Temp Controller Wiring & Fan Wiring Questions. Revvy DIY Projects 12 09-23-2012 01:21 PM
Electrical Question - Grounds and Neutral in a subpanel MDF99 Electric Brewing 3 09-11-2012 02:05 PM
All Grain Future Expansion BigDisplay Equipment/Sanitation 3 02-03-2012 07:22 PM
Kegerator Expansion! TwoHeadsBrewing Home Brewing Photo Forum 1 02-26-2009 07:09 PM