ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals

>> Home   >> Electrical-Photos   >> Classifieds   >> Subscribe to Newsletter   >> Store  
 

Photos of the Week:

1923 Los Angeles Wireman's Handbook
1923 LA Wiremans Hbk

Random Gallery Image:
Recent Gallery Topics:
What in Tarnation?
What in Tarnation?
by timmp, September 10
Plumber meets Electrician
Plumber meets Electrician
by timmp, September 10
Who's Online Now
0 members (), 484 guests, and 16 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
#48268 02/07/05 04:59 PM
Joined: Dec 2004
Posts: 1,064
D
Member
What do you guys use for the service drop wires? In PVc

500mcm copper thhn?
600 alum?
And the same question for wiring into the panels, in pvc,
2/0 copper, 3/0 alum
just curious of the costs.

Horizontal Ad
#48269 02/07/05 05:02 PM
Joined: Dec 2003
Posts: 751
E
Member
parallel 250 kcmil alum.


Earl
#48270 02/07/05 06:48 PM
Joined: Jan 2003
Posts: 4,391
I
Moderator
Quote
parallel 250 kcmil alum

Boy if those are in the same raceway that is pushing it as much as possible and is only acceptable if the calculated load is less than 368 amps.

250 AL rated 230 amps @ 90 C, four current carrying conductors in a raceway.

230 x 2 x .8 = 368 amps.

240.4(B) allows the next standard breaker however the calculated load must stay below 368 amps.

The last 400 amp overhead I did used one set of 600 Kcmil copper.

In my opinion you are not providing a 400 amp service with 500 kcmil copper (380 amps) or two sets of 250 kcmil aluminum (368 amps).

The service can only be rated as high as the lowest rated component.

Of course take this all for what it's worth, I do commercial work so Table 310.15(B)(6) is out of the question. [Linked Image]

Bob


Bob Badger
Construction & Maintenance Electrician
Massachusetts
#48271 02/11/05 03:13 PM
Joined: Jan 2003
Posts: 4,391
I
Moderator
Just bringing this up to the top, I was hoping for some more comments. [Linked Image]

Bob


Bob Badger
Construction & Maintenance Electrician
Massachusetts
#48272 02/11/05 03:35 PM
Joined: Apr 2002
Posts: 7,413
Likes: 8
Member
Bob:
OK, it's on top, I'll bite...
500kcmil cu; 4" PVC or RGC dependent on spec's. Occasionally 600 al, but that's a rare bird.

UG is PVC, unless the 1 PE does the spec....
last time I got a change order & spec change in "clouds" when I verified the $$$ of RGC.

Going to the panels....cu, usually 4/0.

John


John

Link Copied to Clipboard
Advertisement:-Right


Tools for Electricians
Tools for Electricians
 

Member Spotlight
renosteinke
renosteinke
Blue Collar Country
Posts: 5,476
Joined: January 2005
Top Posters(30 Days)
Admin 3
CSS 1
Popular Topics(Views)
365,643 Are you busy
288,638 Re: Forum
267,176 Need opinion
New Page 2
Powered by UBB.threads™ PHP Forum Software 7.7.5