DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Electrical (http://www.diychatroom.com/f18/)
-   -   Under-rated service drop? (http://www.diychatroom.com/f18/under-rated-service-drop-23342/)

fw2007 07-08-2008 08:37 AM

Under-rated service drop?
 
Hi;
About 10 years ago, we put an addition on our home, and the electrical panel was replaced. The service was upgraded from 100A (220V) to 200A.
The service cable was changed, but not the utility's drop from the pole.
The service wire is obviously much larger than the wire from the pole.
Compared to my neighbor's service, our wire (from the pole to the house) is definitely a lot smaller.

I'm wondering why the utility did not replace their wire when the service was upgraded.

FW

jbfan 07-08-2008 09:17 AM

They follow much different rules about wire then we do in a house.
Most of the time, they will not upgrade unless you have an old 60 amp service.

fw2007 07-08-2008 09:51 AM

I guess if we were really drawing close to our 200Amp capacity, we might notice a larger voltage drop, and perhaps convince the utility to upgrade the drop. Currently, we aren't even close to that.

FW

J. V. 07-08-2008 10:54 AM

Quote:

Originally Posted by fw2007 (Post 137043)
Hi;
About 10 years ago, we put an addition on our home, and the electrical panel was replaced. The service was upgraded from 100A (220V) to 200A.
The service cable was changed, but not the utility's drop from the pole.
The service wire is obviously much larger than the wire from the pole.
Compared to my neighbor's service, our wire (from the pole to the house) is definitely a lot smaller.

I'm wondering why the utility did not replace their wire when the service was upgraded.

FW

Because they can do anything they want! Remember your wires are overhead in free air not in conduit.
I have two poles. One on the road with a transformer on it and another pole in my yard. The wires between the two poles were not touched, but the under ground lateral was increased in size. I think they used 4/0 AL.

BigJimmy 07-08-2008 01:36 PM

Quote:

Originally Posted by J. V. (Post 137081)
Remember your wires are overhead in free air not in conduit.

We have a winner! Just look at the tables in the NEC (well, I don't expect you, the OP to; Only nerds like me concern themselves with goofiness like this!) and note the difference in allowable ampacity between the same conductor number/size in raceway vs. free air. You can get a much higher rating for a service drop. Now the service point, i.e. where the service conductors are tapped to the drop, represents the demarcation point between the homeowner and utility. At this point, we all have to play by the NEC rules. Also as J.V. mentioned, they (POCo) can do pretty much what they want and that being said, they will size the conductors according to an anticipated maximum load, regardless of what size panel you have (their numbers come from years of experience).

fw2007 07-08-2008 08:24 PM

I guess that's how they (the utility) get away with the ancient wiring on the street.
We still have the separate 3-wire system, not the twisted set used today.
The transformer is also very ancient. I'm hoping that the day it decides to pop, my car won't be sitting out on the street, 1/2 pole away.
I had a dream the other night that it (the transformer) exploded. I hope it's not a premonition<g>. Wonder what kind of answer I would get from the PC if I told them I thought the transformer should be replaced... NOW! because I dreamed that it was going to explode...

One did explode on the block behind our house, but I wasn't there to witness it.

FW


All times are GMT -5. The time now is 03:46 PM.