Service Drop Size?

Archive Public Archive
#1

Originally Posted By: Russell Frame
This post was automatically imported from our archived forum.


My education continues…


Power Co is at my house right now making the service drop connection.

I spent good money on 2/0 cable to run from the drip loop to the meter and into the panel.

Wife called me to say it looks like they are hooking up #2 overhead triplex between the transformer and my overhead mast.

I asked my wife to go confirm that they were hooking up for 200A, he says "yep, all the wire looks the same for this stuff"

![icon_eek.gif](upload://yuxgmvDDEGIQPAyP9sRnK0D0CCY.gif)

Here's a photo:

Click

Can you electrical guru's explain this to me.

#2

Originally Posted By: Guest
This post was automatically imported from our archived forum.


?"

#3

Originally Posted By: jpope
This post was automatically imported from our archived forum.


The utility company can hook up just about anything they want. This was for a 400 amp service.


![](upload://h3ffssn3YlCYMvzfMt6d2IUsBds.jpeg)

--
Jeff Pope
JPI Home Inspection Service
"At JPI, we'll help you look better"
(661) 212-0738

#4

Originally Posted By: phinsperger
This post was automatically imported from our archived forum.


The overhead service drop can use smaller gauge wire because it is in free air and can disipate heat much better than the ones running down inside your service mast.

–
.



Paul Hinsperger
Hinsperger Inspection Services
Chairman - NACHI Awards Committee
Place your Award Nominations
here !
#5

Originally Posted By: Greg Fretwell
This post was automatically imported from our archived forum.


The power company is regulated by the NESC so it is not exactly “anything they want to do”.


The main difference is their drop is single conductors in free air, not wires in a raceway or cable so the ampacity is higher. Since the I2R losses are on their side of the meter it is up to them how hard they want to push it.


Most 200a services seldom actually run more than 60-70a for any length of time.

#6

Originally Posted By: jtedesco
This post was automatically imported from our archived forum.


The drip loops are not correct, they are to be made in the service entrance conductors!


![](upload://3s6ZlQoaKJhTl3wUCEMuVcseSXc.jpeg)

Drip loops shall be formed on individual conductors. To prevent the entrance of moisture, service-entrance conductors shall be connected to the service-drop conductors either (1) below the level of the service head or (2) below the level of the termination of the service-entrance cable sheath

--
Joe Tedesco, NEC Consultant

www.nachi.org/tedescobook.htm

#7

Originally Posted By: bbadger
This post was automatically imported from our archived forum.


Joe I do not see where it says the drip loops can not be on the utility conductors.


Quote:
230.54(F) Drip Loops. Drip loops shall be formed on individual conductors. To prevent the entrance of moisture, service-entrance conductors shall be connected to the service-drop conductors either (1) below the level of the service head or (2) below the level of the termination of the service-entrance cable sheath.


All I see is below the service head or SE cable sheath.

Russell Do not concern yourself with the power company wiring they have a lot of historical data that they base conductor sizes on. I agree with the others that they follow different rules, most follow the NESC.

I go to a forum that has a power company engineer on it and he claims they typically figure the real load will be 50% of what the NEC calculated load is.

If you tried to figure out the transformer sizes they use you would really be surprised. ![icon_lol.gif](upload://zEgbBCXRskkCTwEux7Bi20ZySza.gif)

--
Bob Badger
Electrical Construction & Maintenance
Moderator at ECN
#8

Originally Posted By: Russell Frame
This post was automatically imported from our archived forum.


Quote:
Russell Do not concern yourself with the power company wiring they have a lot of historical data that they base conductor sizes on. I agree with the others that they follow different rules, most follow the NESC.

I go to a forum that has a power company engineer on it and he claims they typically figure the real load will be 50% of what the NEC calculated load is.

If you tried to figure out the transformer sizes they use you would really be surprised. ![icon_lol.gif](upload://zEgbBCXRskkCTwEux7Bi20ZySza.gif)


Thanks Bob. The installers didn't have my faith due to some general comments and observations they made earlier in this process and when I saw the small conductors I got concerned that they were just "throwing up what they had on the truck". I've since talked to some engineers about this and they concur with the comments made above that the Power Co's definitely have different rules about this stuff. As for the drip loop comment, I dont see how Joe is reading it the way he is reading it, but that again was the Power Co's work so I will defer to their expertise.

Now I can enjoy the fact that my new house is alive!
#9

Originally Posted By: jtedesco
This post was automatically imported from our archived forum.


Bob: and Russell:


The Section 230.54(F) I mentioned is in Part IV. Service-Entrance Conductors, and the "drip loop" is supposed to be in the service entrance conductors. ![icon_rolleyes.gif](upload://iqxt7ABYC2TEBomNkCmZARIrQr6.gif)

Quote:
As for the drip loop comment, I dont see how Joe is reading it the way he is reading it, but that again was the Power Co's work so I will defer to their expertise.


PS: Was the job inspected? Was there a permit?

Quote:
230 Services .............................................. 70? 75

I. General ........................................... 70? 75

II. Overhead Service-Drop Conductors ......... 70? 77

III. Underground Service-Lateral
Conductors ........................................ 70? 78

IV. Service-Entrance Conductors ................. 70? 78

V. Service Equipment ? General ............... 70? 81

VI. Service Equipment ? Disconnecting
Means ............................................ 70? 81

VII. Service Equipment ? Overcurrent
Protection ........................................ 70? 82
VIII. Services Exceeding 600 Volts, Nominal .... 70? 84


--
Joe Tedesco, NEC Consultant

www.nachi.org/tedescobook.htm
#10

Originally Posted By: bbadger
This post was automatically imported from our archived forum.


Joe I guess we will have to disagree on this one. icon_smile.gif


Can you tell me what difference it makes which wires have the bend on them as long as the loops are below the weather head or cable sheath?

I would have to laugh if an electrical inspector made an issue of this.

Bob

--
Bob Badger
Electrical Construction & Maintenance
Moderator at ECN

#11

Originally Posted By: Russell Frame
This post was automatically imported from our archived forum.


Quote:
PS: Was the job inspected? Was there a permit?


There is no code enforcement here or electrical permit required as this is a rural location.

That said it has been my goal to perform all work to be compliant, both for safety and as an educational experience. (As you can see from this post).
#12

Originally Posted By: Greg Fretwell
This post was automatically imported from our archived forum.


You are right about one thing. They do use what they have on the truck but that is the drop for 200a service, no matter whether you actually have 200, 150 or 100. That is why they don’t swap out the drop on most service upgrades if it is triplex. It is also why they wince at greater than 200a and you still may get the same drop as your neighbor.


The only time I would question a drop size on 200a if it is the old 3 strand separate conductor thing. The twisted “triplex” seems to be the same for everyone.

#13

Originally Posted By: lfranklin
This post was automatically imported from our archived forum.


Quote:
The only time I would question a drop size on 200a if it is the old 3 strand separate conductor thing.


Are you talking about the old 60 amp service
#14

Originally Posted By: Greg Fretwell
This post was automatically imported from our archived forum.


lfranklin wrote:
Quote:
The only time I would question a drop size on 200a if it is the old 3 strand separate conductor thing.


Are you talking about the old 60 amp service


Yep I would think that is what a 60a would use. We had 100a in the 50s and that was it. By sometime in the 70s they had started using triplex and I have never seen any that wouldn't go 200a ... at least as far as the utility said. When I put in my 200a panel here in Fla the only question the engineer at FPL asked me was did I have triplex.
The customer owns everything from the "service point" where the drip loop and crimps are. That I did have to upgrade.