utility wire ampacity

[Len]

IN PA i know alot of the PECO designers but out here in FL it is different i don't know anyone. Does anyone know how FPL rates there underground cables? Like the ampacity of the utility service 4/0 al. they don't use the NEC tables they go by there own i beleive same as utility back home.

 

[iwire]

They don't go by NEC tables but more importantly they do not go by the size of the breaker we install or the load calculation in the NEC. They go by their own history of knowing how much load certain buildings will have.

 

[peter d]

IN PA i know alot of the PECO designers but out here in FL it is different i don't know anyone. Does anyone know how FPL rates there underground cables? Like the ampacity of the utility service 4/0 al. they don't use the NEC tables they go by there own i beleive same as utility back home.

They likely run 2/0 AL for an underground service lateral, which is fine even in FL which has many all electric homes.

 

[mgookin]

FPL has a real good construction division. You can call them anytime.

 

[Strathead]

IN PA i know alot of the PECO designers but out here in FL it is different i don't know anyone. Does anyone know how FPL rates there underground cables? Like the ampacity of the utility service 4/0 al. they don't use the NEC tables they go by there own i beleive same as utility back home.

I am not sure exactly what, or why you are asking, but in my 10 years experience in Florida, it is a little odd, at least compared to California. The customer, so ultimately the Electrical Contractor installs the secondary conductors and they are sized by the customer Electrical Engineer on commercial projects. I have never seen a set of secondaries sized for anything but the service disconnect size and table 315 of the NEC. And as an estimator, I see over 100 sets of plans a year. For residential, the POCO's I have interfaced with (which is rare, because I have a voluntary allergy to Romex) size and pull the conductors for underground and overhead, both. Which defaults to the other answers you have received.

 

[iwire]

The customer, so ultimately the Electrical Contractor installs the secondary conductors and they are sized by the customer Electrical Engineer on commercial projects. I have never seen a set of secondaries sized for anything but the service disconnect size and table 315 of the NEC.

Depending on which power company we are dealing with it sometimes goes the same way here for commercial projects. The point of service is at the transformer secondary terminations so the NEC starts at that point.

 

[mgookin]

With FPL the service point is at the weatherhead on aerial. POCO will install the service drop.

For u/g it's the lineside connection at the meter. The EC installs the run from meter to tranny secondary on new construction or upgrades, but POCO takes ownership of it. This run has to meet FPL spec.

One thing that confuses people is that FPL won't connect to the tranny secondary on an ungrounded 3p delta without a grounded conductor there; just a heads up.

Whether aerial or u/g these runs are deemed to have an "easement by consent".

You can call their construction division and they'll be very helpful.

 

[Strathead]

With FPL the service point is at the weatherhead on aerial. POCO will install the service drop.

For u/g it's the lineside connection at the meter. The EC installs the run from meter to tranny secondary on new construction or upgrades, but POCO takes ownership of it. This run has to meet FPL spec.

One thing that confuses people is that FPL won't connect to the tranny secondary on an ungrounded 3p delta without a grounded conductor there; just a heads up.

Whether aerial or u/g these runs are deemed to have an "easement by consent".

You can call their construction division and they'll be very helpful.

I believe this is only true for commercial applications. Doesn't the POCO install the underground service laterals for residential?

 

[mgookin]

I believe this is only true for commercial applications. Doesn't the POCO install the underground service laterals for residential?

Good point. MasTech is probably working for POCO on single family, not the GC.
When I started with the city 25 years ago our then chief electric inspector used to argue that a contractor hired by POCO is not exempt because that contractor is not a public utility.
But he's working on POCO side of the service point, so he's exempt from the NEC, so what's there to issue a permit on and inspect? Nothing.

 

[peter d]

When I started with the city 25 years ago our then chief electric inspector used to argue that a contractor hired by POCO is not exempt because that contractor is not a public utility.

That's absurd and if an inspector tried that here he would get laughed into next week.

 

[mbrooke]

Good point. MasTech is probably working for POCO on single family, not the GC.
When I started with the city 25 years ago our then chief electric inspector used to argue that a contractor hired by POCO is not exempt because that contractor is not a public utility.
But he's working on POCO side of the service point, so he's exempt from the NEC, so what's there to issue a permit on and inspect? Nothing.

Even under the NEC's conservative tables, the service drop will still be smaller than the actual service conductors.