how to tie a subpanel to a main panel? - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Garage - Tools
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 09-19-2006, 02:52 PM
bet on black's Avatar
hotrodder 4 life
 
Last photo:
Join Date: Oct 2004
Location: houston, tx
Age: 32
Posts: 169
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
how to tie a subpanel to a main panel?

i have a 250A main panel on my house. the garage is detatched, and about 20 ft. away from the house. i want 100A service out there and had a question, how do you tie in the subpanel to the main?

Last edited by bet on black; 09-26-2006 at 08:56 AM.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 09-19-2006, 03:47 PM
Kruzin Karl
 
Last photo:
Join Date: Sep 2004
Location: Sunny South Florida
Age: 43
Posts: 153
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Normally, you would attatch minimum of 1" grey PVC electrical conduit to the bottom of a knockout on your main, bury the pipe using sweeps or a heat gun, and run it to your subpanel.
BUT, you can't add another 100 amps service onto your main if it's only 100 to begin with. You better check that first. If your wire size coming in to your main panel, and the panel itself is set up for it, sometimes you can just change the main breaker on the panel to a larger amperage.
If you're not sure about this, cough up the dinero and pay an electrician, better to be out a little bit of money than have the house burn down or electrocute yourself!
Good luck - Karl.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 09-19-2006, 07:02 PM
Registered User
 
Last photo:
Join Date: Jun 2006
Location: Kentucky
Posts: 24
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
There is a lot to consider when installing a subpanel. First, off you need to do what is called a demand load calculation to find out what you really need in the garage. I have a 100 amp panel in the garage as subpanel fed by a 60 amp breaker in the main box. 60 amps is all that I needed and I have a two stage compressor, mig welder, several lighting circuits, receptacles around the walls etc. A one man shop can only use one tool at a time. Code requires a detached garage to be fed by a 4 wire feeder for 230 volts - 2 hots, one nuetral, and a ground.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 09-19-2006, 07:19 PM
S10xGN's Avatar
Gotta love a turbo!
 

Last journal entry: Body on Frame today.
Last photo:
Join Date: Aug 2004
Location: Port Neches, TX
Age: 60
Posts: 1,557
Wiki Edits: 0

Thanks: 0
Thanked 49 Times in 47 Posts
Quote:
Originally Posted by 68C10
There is a lot to consider when installing a subpanel. First, off you need to do what is called a demand load calculation to find out what you really need in the garage. I have a 100 amp panel in the garage as subpanel fed by a 60 amp breaker in the main box. 60 amps is all that I needed and I have a two stage compressor, mig welder, several lighting circuits, receptacles around the walls etc. A one man shop can only use one tool at a time. Code requires a detached garage to be fed by a 4 wire feeder for 230 volts - 2 hots, one nuetral, and a ground.
Pretty much (well, exactly) how mine is done!

Russ
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 09-19-2006, 07:50 PM
Kruzin Karl
 
Last photo:
Join Date: Sep 2004
Location: Sunny South Florida
Age: 43
Posts: 153
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Yep, load calculations are very important. My Esab plasma cutter alone could draw close to 70 amps if cutting heavy metal. Generally calculating the amperage draw of all the equipment you would most likely ever have on at one time will give you a good idea of how big a subpanel you really need.
Later - Karl.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 09-19-2006, 08:45 PM
58Chev's Avatar
Building a 10 footer.
 

Last journal entry: No more room in my garage.
Last photo:
Join Date: Nov 2005
Location: Ontario
Age: 49
Posts: 156
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by 68C10
I have a 100 amp panel in the garage as subpanel fed by a 60 amp breaker in the main box. 60 amps is all that I needed..
A one man shop can only use one tool at a time.
Is that an actual sub-panel or are ya re-using a main panel?

I have a 100amp main panel in my garage with a 40Amp breaker in the main box. There is a screw that grounds the common and that has to be removed from the sub-panel if it was once a main.

The largest draw I have is 30Amps from my welder. As you mentioned, only a one man shop so I won't be welding and using my compressor at the same time.

bet on black,
If you really think you need 100Amp in the garage, bump up your house panel to 200Amp service first. If not just add a 40 or 60 amp breaker and run the garage off of that.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 09-19-2006, 09:06 PM
bet on black's Avatar
hotrodder 4 life
 
Last photo:
Join Date: Oct 2004
Location: houston, tx
Age: 32
Posts: 169
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
ok, i looked at the panel when i got home, it has two 125 amp breakers for the main breaker, and there are a couple slots left. so i should be able to tie it in, i think. i want to build the system to allow for the largest load i could possibly put on it. a bunch of lights, an air conditioner, and a plasma cutter could put me close to 70 or 80 amps.

i know about the load function, i was more concerned with how to actually tie in the wires to the box and hook up the subpanel, than what size breakers i need.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 09-20-2006, 09:47 AM
Registered User
 
Last photo:
Join Date: Jun 2006
Location: Kentucky
Posts: 24
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Mine panel was bought at Lowes and is a GE "garage pak". It comes with the green bonding screw not installed and was not used since I have a four wire feeder. The panel came with a main breaker and also 5 20 amp breakers. I purchased the other breakers for compressor etc.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 09-21-2006, 08:05 PM
sbchevfreak's Avatar
Licenced Automotive Technician
 
Last photo:
Join Date: Feb 2004
Location: Land of big Easter eggs, Alberta
Age: 34
Posts: 1,604
Wiki Edits: 0

Thanks: 8
Thanked 9 Times in 9 Posts
Quote:
know about the load function, i was more concerned with how to actually tie in the wires to the box and hook up the subpanel, than what size breakers i need.
Before you start adding panels, I'd check into local codes and your insurance policies. Many companies have policies that say you need an electrician to install such items, or you may void your insurance.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 09-23-2006, 06:04 AM
1ownerT's Avatar
Home School Valedictorian
 
Last wiki edit: Health and safety in the shop or garage Last photo:
Join Date: Dec 2004
Location: Iowa
Age: 52
Posts: 1,645
Wiki Edits: 4

Thanks: 0
Thanked 3 Times in 3 Posts
Quote:
Originally Posted by 58Chev
Is that an actual sub-panel or are ya re-using a main panel?

I have a 100amp main panel in my garage with a 40Amp breaker in the main box. There is a screw that grounds the common and that has to be removed from the sub-panel if it was once a main.

The largest draw I have is 30Amps from my welder. As you mentioned, only a one man shop so I won't be welding and using my compressor at the same time.

bet on black,
If you really think you need 100Amp in the garage, bump up your house panel to 200Amp service first. If not just add a 40 or 60 amp breaker and run the garage off of that.
I thought about doing that until I found out that the house has to be brought up to current code, way more money that I wanted to spend. I ended up with a 60 breaker feeding the garage.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 09-23-2006, 09:14 AM
pmeisel's Avatar
Glad the Jeep is on the road
 
Last wiki edit: How to identify a Ford V8
Join Date: Jan 2004
Location: Meridian MS & Vermilion Ohio
Age: 57
Posts: 814
Wiki Edits: 8

Thanks: 0
Thanked 0 Times in 0 Posts
I upgraded my old house (not the one I am in now) from 100 to 200 amps so I could run an air compressor, fridge and tv in the garage at the same time -- plus the big window air conditioner kept kicking a breaker because we didn;t have enough circuits upstairs. It only cost a few hundred bucks.

sounds like you are set... but for anyone else, figure out how much juice you think you need and multiply by two, there will always be more to add and you never take anything out....
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 09-23-2006, 09:27 AM
1ownerT's Avatar
Home School Valedictorian
 
Last wiki edit: Health and safety in the shop or garage Last photo:
Join Date: Dec 2004
Location: Iowa
Age: 52
Posts: 1,645
Wiki Edits: 4

Thanks: 0
Thanked 3 Times in 3 Posts
Estimates I received were way more than a few hundred bucks. I don't know what your codes are to your specific area, but for me it ment moving the meter out of the basement to an outside wall (new service to the house, weatherhead, conduit to get power from meter to the new panel) all circuits have to be grounded, separate circuits for dishwasher, micro wave, any receptacle within 4' of sink has to be GFCI. You can not buy the materials for a few hundred, then the labor- if your house is anything like mine most circuits would be impossible to access without cutting up some drywall.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 09-25-2006, 09:16 AM
bet on black's Avatar
hotrodder 4 life
 
Last photo:
Join Date: Oct 2004
Location: houston, tx
Age: 32
Posts: 169
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
my panel is on an exterior wall, right in front of the garage, so that is not an issue, my next problem is getting across the driveway.
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 09-25-2006, 03:29 PM
Kruzin Karl
 
Last photo:
Join Date: Sep 2004
Location: Sunny South Florida
Age: 43
Posts: 153
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
What kind of driveway, and do you have bare dirt on each side of it?
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 09-25-2006, 04:56 PM
1ownerT's Avatar
Home School Valedictorian
 
Last wiki edit: Health and safety in the shop or garage Last photo:
Join Date: Dec 2004
Location: Iowa
Age: 52
Posts: 1,645
Wiki Edits: 4

Thanks: 0
Thanked 3 Times in 3 Posts
Quote:
Originally Posted by bet on black
my panel is on an exterior wall, right in front of the garage, so that is not an issue, my next problem is getting across the driveway.
To update a panel from 100 amp to 200 amp requires a new feeder from the transformer to the panel, it is very unlikely that the feeders you have now will support 200 amp. At least where I am, to get the feeders updated you have to pull a permit, that means an electrician, and when that is issued it will be required that you update the house to current code. If your house is new enough the update should be minimal.
Reply With Quote Quick reply to this message

Recent Garage - Tools posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Building A 302 Chevy Scorpio Shaping Flow Hotrodding Basics 6 01-16-2007 05:55 AM
Help! What To Do With These GIGANTIC Dents!? mistermuscles Body - Exterior 14 09-16-2005 05:24 AM
wanted: an answer to a simple question ikeaguirre14 Body - Exterior 4 05-15-2005 07:23 PM
Repair of large dents in roof? rlackey Body - Exterior 9 01-28-2005 10:36 PM
Quarter Panel Patch Ron M Body - Exterior 1 07-27-2004 01:12 AM


All times are GMT -6. The time now is 05:40 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.