EMT Conduit/Junction/Grounding - Electrical - DIY Chatroom Home Improvement Forum


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 09-15-2011, 02:02 PM   #1
Member
 
Join Date: Dec 2010
Posts: 34
Rewards Points: 25
Default

EMT Conduit/Junction/Grounding


I am running 2x 20Amp circuits inside 1/2" EMT conduit. Base on a calculation, I should be able to run 4 circuits with #12 THHN wires (4 Hots, 4 Neutral, 1 ground). I plan to run 1 insulated ground wire.

My questions are:

1) Do I have to ground every metal junction box?
2) Is there any limit in length of EMT conduit between junction boxes?
3) If I use 1 ground wire, can I use #12 or I will need a bigger since this will be a shared ground.
4) Do I need to color coded different hot wires? Or it is ok just to tape wires at the end?
5) Can I wrap each circuit together with electrical tape? (E.g. wrap it every 3-4 feets).

TIA

Advertisement

cfreak is offline   Reply With Quote
Old 09-15-2011, 02:15 PM   #2
Member
 
Code05's Avatar
 
Join Date: May 2009
Location: Easton MD
Posts: 1,841
Rewards Points: 1,000
Default

EMT Conduit/Junction/Grounding


Quote:
1) Do I have to ground every metal junction box?
If there is an wire EGC/ground, yes.

Quote:
2) Is there any limit in length of EMT conduit between junction boxes?
No

Quote:
3) If I use 1 ground wire, can I use #12 or I will need a bigger since this will be a shared ground.
EGC/ground wires needs not be larger than hots.

Quote:
4) Do I need to color coded different hot wires? Or it is ok just to tape wires at the end?
Unless you have more than 1 supply, no identification necessary.

Quote:
5) Can I wrap each circuit together with electrical tape? (E.g. wrap it every 3-4 feets).
Why. MWBC need only be grouped at panel.

Advertisement

Code05 is offline   Reply With Quote
The Following User Says Thank You to Code05 For This Useful Post:
cfreak (09-15-2011)
Old 09-15-2011, 03:13 PM   #3
Member
 
Join Date: Oct 2009
Posts: 853
Rewards Points: 626
Default

EMT Conduit/Junction/Grounding


You do know that you can use the EMT as your ground, and not run a ground wire inside the conduit?
Anti-wingnut is offline   Reply With Quote
The Following User Says Thank You to Anti-wingnut For This Useful Post:
cfreak (09-15-2011)
Old 09-15-2011, 04:28 PM   #4
Member
 
Join Date: Dec 2010
Posts: 34
Rewards Points: 25
Default

EMT Conduit/Junction/Grounding


Quote:
Originally Posted by Anti-wingnut View Post
You do know that you can use the EMT as your ground, and not run a ground wire inside the conduit?
Yes, I read about that in one thread but there are negative opinions about doing so.

Just wondering, what are the different/limitation when using EMT, bare cooper, insulated EGC/ground?

Thanks,
cfreak is offline   Reply With Quote
Old 09-15-2011, 04:37 PM   #5
Member
 
Code05's Avatar
 
Join Date: May 2009
Location: Easton MD
Posts: 1,841
Rewards Points: 1,000
Default

EMT Conduit/Junction/Grounding


Quote:
Originally Posted by cfreak View Post
Yes, I read about that in one thread but there are negative opinions about doing so.

Just wondering, what are the different/limitation when using EMT, bare cooper, insulated EGC/ground?

Thanks,
All three are legal.
Code05 is offline   Reply With Quote
The Following User Says Thank You to Code05 For This Useful Post:
cfreak (09-15-2011)
Old 09-15-2011, 05:21 PM   #6
Electrician
 
Join Date: Nov 2005
Location: Winnipeg, Manitoba
Posts: 1,159
Rewards Points: 534
Default

EMT Conduit/Junction/Grounding


Quote:
Originally Posted by cfreak View Post
Yes, I read about that in one thread but there are negative opinions about doing so.
I do it every day, and would not hesitate to do it my own house. Why are you pulling 4 neutrals, if you use multi wire branch circuits you can get away with two neutrals.
darren is offline   Reply With Quote
Old 09-16-2011, 08:23 AM   #7
Chaos Engineer
 
Big N8's Avatar
 
Join Date: Oct 2009
Location: Coon Rapids MN
Posts: 183
Rewards Points: 150
Default

EMT Conduit/Junction/Grounding


Quote:
Originally Posted by darren View Post
I do it every day, and would not hesitate to do it my own house. Why are you pulling 4 neutrals, if you use multi wire branch circuits you can get away with two neutrals.

I agree you can take three of those wires out of that conduit and be 100% safe and 100% to code (unless some silly local code comes into play)
Big N8 is offline   Reply With Quote
Old 09-16-2011, 08:27 AM   #8
Member
 
Code05's Avatar
 
Join Date: May 2009
Location: Easton MD
Posts: 1,841
Rewards Points: 1,000
Default

EMT Conduit/Junction/Grounding


Quote:
Originally Posted by darren View Post
Why are you pulling 4 neutrals, if you use multi wire branch circuits you can get away with two neutrals.
MWBC are rapidly disappearing in most residential in the US because of AFCI protection for many 120v circuits. Currently the kitchen, bath, laundry, garage, attic, unfinished basements and exterior outlets are exempt, but who knows for how long.

Here is our code section:

210.12 Arc-Fault Circuit-Interrupter Protection.
(A) Definition: Arc-Fault Circuit Interrupter (AFCI). A
device intended to provide protection from the effects of
arc faults by recognizing characteristics unique to arcing
and by functioning to de-energize the circuit when an arc
fault is detected.
(B) Dwelling Units. All 120-volt, single phase, 15- and
20-ampere branch circuits supplying outlets installed in
dwelling unit family rooms, dining rooms, living rooms,
parlors, libraries, dens, bedrooms, sunrooms, recreation
rooms, closets, hallways, or similar rooms or areas shall be
protected by a listed arc-fault circuit interrupter,
combination-type, installed to provide protection of the
branch circuit.
Code05 is offline   Reply With Quote
Old 09-16-2011, 04:21 PM   #9
Electrician
 
Join Date: Nov 2005
Location: Winnipeg, Manitoba
Posts: 1,159
Rewards Points: 534
Default

EMT Conduit/Junction/Grounding


Were lucky here then, we only have to do bedrooms on arc faults.

I didn't consider the circuits in the pipe may have been arc fault but if they are you will need seperate neutrals.

Advertisement

darren is offline   Reply With Quote
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





Top of Page | View New Posts