Undersized service cable

[inspectorwill]

The property has two structures with one service cable that appears original (circa 1950s), two meters and two main panels. Both main panels have been upgraded to 100 amp panels with permits. Generally, who determines whether a service cable upgrade is required? This seems absurd to me that a 60 year old undersized service cable is supplying two 100 amp panels.

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[Marc]

Age alone doesn't matter. Condition and ampacity matter. For your installation the combined load of the two buildings needs to be calculated to determine the size of the common service conductors. That calculation doesn't involve the size of the main breakers, just the loads.

Marc

[John Kogel]

Age alone doesn't matter. Condition and ampacity matter. For your installation the combined load of the two buildings needs to be calculated to determine the size of the common service conductors. That calculation doesn't involve the size of the main breakers, just the loads.

Marc

I must disagree. Loads can be increased by the occupants at any time. In this case, they can load up to 200 amps without tripping a breaker. The service conductors need to be sized to the potential load.

I'm talking about the run inside the wall down from that antique weatherhead. What the power company does with the service drop is up to them, and that part is air-cooled, anyway.

In my area, the power company would have installed the second meter, after a contractor installed the meter can with the approval of a government electrical inspector. Three sets of eyes would have looked at that.

BTW, speaking of condition, the insulation is in poor condition. I'd call for an immediate repair.

[Jim Katen]

The property has two structures with one service cable that appears original (circa 1950s), two meters and two main panels. Both main panels have been upgraded to 100 amp panels with permits. Generally, who determines whether a service cable upgrade is required?

Typically, when you apply for a permit to add large electrical loads or to simply upgrade the service panel, that would kick in a review of the utility service equipment. At that point, the utility would determine whether its service drop cable and meter were properly matched to your building.

Of course, if you bootleg the upgrades, then the utility doesn't get clued into the the change and nothing happens.

This seems absurd to me that a 60 year old undersized service cable is supplying two 100 amp panels.

The owner can simply call the utility anytime and get an answer.

[inspectorwill]

Thanks. I guess I assumed the local building dept. would require a review of the service equipment by the utility company before allowing the installation of the two panels.