Thoughts On Wiring New Attached Garage/hallway - Electrical - Page 2 - DIY Chatroom Home Improvement Forum
Advertisement


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools
Display Modes
Old 05-03-2010, 10:10 AM   #16
Member
 
Join Date: Jan 2009
Location: South of Boston, MA
Posts: 17,248
Rewards Points: 2,000
Default


As long as the loads are balanced across the hot feeds it should be enough power
If you draw more then 40a 120v on either leg the main breaker will trip
75a is the total circuit capacity, not the total load

If you have any doubts go to a 60a panel

In a perfect world you could draw close to 40a on each leg



Scuba_Dave is offline   Reply With Quote
The Following User Says Thank You to Scuba_Dave For This Useful Post:
Mi Feller (05-03-2010)
Sponsored Links
Advertisement
 
Old 05-03-2010, 10:10 AM   #17
Licensed electrician
 
Join Date: Sep 2007
Location: Maryland
Posts: 12,413
Rewards Points: 3,662
Default


Just because the breaker handle says 15 or 20 amps does not mean that is what is actually being used. A typical refrigerator may only use 6-7 amps. A garage door opener is probably less.
__________________
Answers based on the National Electrical Code. Local amendments may apply. Check with your local building officials.
Jim Port is offline   Reply With Quote
The Following User Says Thank You to Jim Port For This Useful Post:
Mi Feller (05-03-2010)
Sponsored Links
Advertisement
 
Old 05-03-2010, 10:11 AM   #18
Member
 
Join Date: Mar 2010
Location: Michigan
Posts: 107
Rewards Points: 75
Default

RE: Amps for opener and refrig


Thanks Andrew. Will never come close to using all that amperage. Reason for opener on dedicated circuit is that GFI now required on all garage outlets and don't want to risk one of the wall outlets tripping and causing door not to open. Refrig says only "10.2 LRA" on back. Guessing that the amps. Have a chart showing a 1/4 hp door opener motor requires 500W resistive load / 1000W reactive. That should be only about 8.33A, but don't yet have the device. Builder will supply it. Could be larger. Have to think a 15A might be plenty there.
Mi Feller is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 05-03-2010, 11:15 AM   #19
Member
 
Join Date: Mar 2010
Location: Michigan
Posts: 107
Rewards Points: 75
Default

Total draw vrs. total circuits


Appreciate if someone would please confirm my understanding. Your responses to earlier question helped alot. It appears total draw is what's really important. For example, in examining house's main breaker box installed by an electrician in '99 I note the following: (1) a 200 AMP main breaker at bottom of box and (2) a total circuit loading of 465 @ 120V evenly distributed. Have had no problems. By adding a 240 40Amp for new garage, I'll increase total circuit amperage to 505 @120V and still would expect no problems with minimal additional draw. In fact the refrig going there. is simply being moved from another location where it is already drawing load. Thanks for the help.
Mi Feller is offline   Reply With Quote
Old 05-03-2010, 11:20 AM   #20
Licensed electrician
 
Join Date: Sep 2007
Location: Maryland
Posts: 12,413
Rewards Points: 3,662
Default


Not sure if it was one of your posts or not. Adding the rating of the breaker handles does not equal the load on the system. Some items are only using a portion of the breaker rating. Also adding the handles does not account for items like the heating and air conditioning that are not used at the same time.

The true method is a demand load calculation which is based on square footage and the actual draw of appliances.
__________________
Answers based on the National Electrical Code. Local amendments may apply. Check with your local building officials.
Jim Port is offline   Reply With Quote
The Following User Says Thank You to Jim Port For This Useful Post:
Mi Feller (05-03-2010)
Old 05-03-2010, 11:24 AM   #21
Member
 
Join Date: Jan 2009
Location: South of Boston, MA
Posts: 17,248
Rewards Points: 2,000
Default


2 threads on same issue merged
I have a 200a service & have well over 1000a in breakers
To calculate your whole house draw at what would be considered the Max you do a whole house electric calculation
My calc comes in at ~142a

A basic calculation is your electric bill
If your bill isn't $650+ a month you should be fine



Scuba_Dave is offline   Reply With Quote
The Following User Says Thank You to Scuba_Dave For This Useful Post:
Mi Feller (05-03-2010)
Old 05-03-2010, 07:00 PM   #22
Member
 
Join Date: Mar 2010
Location: Michigan
Posts: 107
Rewards Points: 75
Default

Thanks all for the imput


I think I got it all figured out now. Also spoke to the electrical inspector (but he's hard to get ahold of and only 2 hours per day). Just awaiting the new attached garage to go up and will get busy with the wiring. Thanks for all the good advice over past several weeks.
Mi Feller is offline   Reply With Quote
Old 05-18-2010, 10:27 PM   #23
Member
 
Join Date: Mar 2010
Location: Michigan
Posts: 107
Rewards Points: 75
Default

Do you need to use a surface mount box for duplex recepticals in unfinished garage?


Plan to use same type of box/cover plate you would use for flush mounted receptacles, but without drywall or anything around them. Have seen this in older unfinished garagea. Or, do you now have to use a specially designed surface mount box for this application? Thanks.
Mi Feller is offline   Reply With Quote
Old 05-19-2010, 02:10 AM   #24
Member
 
Join Date: Jun 2007
Posts: 4,110
Rewards Points: 310
Default


Most people will use 1900 boxes (4x4) with raised covers mounted directly to the block or concrete wall. Here are a few examples.
Attached Images
       
J. V. is offline   Reply With Quote
The Following User Says Thank You to J. V. For This Useful Post:
Mi Feller (05-19-2010)
Old 05-20-2010, 09:29 PM   #25
Member
 
Join Date: Mar 2010
Location: Michigan
Posts: 107
Rewards Points: 75
Default

Sub pannel in new attached garage disconnect requirements


It's my understanding that with a 40A sub-panel in new attached garage supplied from house's main breaker panel, a disconnect at the point of entry into the attached garage is unnecessary. Disconnect would essentially be the 40A circuit breaker located in the house's breaker box. Hope this is correct and per NEC. Thanks for any insights.
Mi Feller is offline   Reply With Quote
Old 05-20-2010, 09:36 PM   #26
Member
 
Join Date: Jan 2009
Location: South of Boston, MA
Posts: 17,248
Rewards Points: 2,000
Default


Yes, attached structure does not need a main breaker in a sub
I always install a main breaker panel as a sub
Just easier & they have deals w/breakers included w/panel

I used a 100a main breaker panel as a sub in my pool cabana (detached) & fed it with 60a



Scuba_Dave is offline   Reply With Quote
Old 05-20-2010, 09:51 PM   #27
Member
 
Join Date: Mar 2010
Location: Michigan
Posts: 107
Rewards Points: 75
Default


Thanks Dave. I can see the advantages of putting a breaker out there. However, materials are purchased and budget pretty well shot. Needs are minimal as this is a small garage just for parking (door opener, a few lights, etc.) Thanks again.
Mi Feller is offline   Reply With Quote
Old 05-21-2010, 09:25 AM   #28
Member
 
Join Date: Jun 2007
Posts: 4,110
Rewards Points: 310
Default


Quote:
Originally Posted by Mi Feller View Post
Thanks Dave. I can see the advantages of putting a breaker out there. However, materials are purchased and budget pretty well shot. Needs are minimal as this is a small garage just for parking (door opener, a few lights, etc.) Thanks again.
Dave meant you can get a main breaker panel sometimes cheaper than a lug panel.
J. V. is offline   Reply With Quote
The Following User Says Thank You to J. V. For This Useful Post:
Mi Feller (05-23-2010)
Old 05-22-2010, 09:11 AM   #29
Member
 
Join Date: Mar 2010
Location: Michigan
Posts: 107
Rewards Points: 75
Default

Any thoughts minimum stapling requirements near service pannel


Will run two 8-3 cables from bottom of service panel through sub floor to a 30' long crawl space. Have cut 6"Wx24"H hole in drywall under panel. Can attach cables with romex connectors at bottom of panel and can secure with staples directly under sub floor aprox 3' under the panel. This would appear to violate rule that you staple within 12" of a metal box. However, existing wiring would also be in violation as an 8-3 now comes down from panel without staples. Also, main line enters through floor being secured only at the box. Area is crowded with many 12-2's and 14-2s being stapled to the 2 available studs. Hopefully the 12" staple rule does not apply in this situation. Any thoughts? Thanks.
Mi Feller is offline   Reply With Quote
Old 05-22-2010, 11:04 AM   #30
Licensed electrician
 
Join Date: Sep 2007
Location: Maryland
Posts: 12,413
Rewards Points: 3,662
Default


It does apply in this situation since you are not fishing the cables and have access to allow the stapling. Sounds like the original install sidestepped the code requirement.

Perhaps you could install a crosswise stud under the panel to allow you to add the staples.
__________________
Answers based on the National Electrical Code. Local amendments may apply. Check with your local building officials.
Jim Port is offline   Reply With Quote
The Following User Says Thank You to Jim Port For This Useful Post:
Mi Feller (05-22-2010)
Sponsored Links
Advertisement
 
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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 Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Wiring diagram for three-way switches with pilot light SaxTeacher Electrical 34 09-15-2013 07:53 AM
Wiring an Intermatic Wall Timer in a three way switch aitutaki98 Electrical 6 07-23-2011 11:43 AM
Correct wiring diagram for 1 story house jdm001 Electrical 63 06-24-2010 04:35 PM
wiring 100A to detached garage snowman Electrical 4 11-28-2009 04:53 PM
Wiring Sequence on Adding a New Outlet kennykenny Electrical 9 06-09-2008 02:06 PM




Top of Page | View New Posts