I live in Canada and was wondering if anyone knows if you have to change the meter base when your upgrading your panel from 100 amp to 125? I have 1/0 aluminum feeds from city with a new 1 1/4 pipe to inside with number 2 copper. I'm just not sure if the city will complain about me leaving the 100 amp meter base or if I'm suppose to switch it to a 200 amp meter base.

The power company is going to confirm that its 1/0 aluminum at the transformer and the meter base, if so I can replace the #3 copper with #2 and upgrade to a 125A in the house. Its an underground service so to trench and replace the wires could be quite costly. I just don't want to leave the old meter base and get pinched for it. But at the same time I don't want a huge monstrosity (200A meter base) for no reason.

  • If your current meter base is only 100A, you will need a new one rated for at least 125A. I'm surprised you're only increasing by 25%, though. Sep 17, 2017 at 12:14
  • Check with your power company. In most, if not all, of the US, you would need to upgrade both meter and panel to 200amp, or you could use a 125 amp panel with a 100amp main breaker-if you already had the 100amp service My power utility offers services in 4 sizes: 60, 100, 200, 400 with strict guidelines where 60 and 100 can still be installed--basically new residential mostly falls into the 200 amp category.
    – Tyson
    Sep 17, 2017 at 12:53
  • 1
    I find myself intrigued of the choice to go from 100 to only 125 and suspect this was chosen because most of the existing equipment and wires are already sized for it. Have you had this conversation with the power company? Sep 17, 2017 at 14:05

1 Answer 1


Yes, but only if the meter base isn't already 125A. I find it curious that they'd run 1/0Al when #1 would have sufficed for a 100A seevice. It was like someone intended to go to 125 later. Perhaps this same thinking guided the selection of the meter base.

Now, as far as that service panel. Far and away the most painful thing about changing a service panel is physically fitting all the cable entries and conduits to the edge of the box proper. Yet, the working innards are what makes a panel 100 vs 125A, main vs sub, 2-pole vs 3-phase etc. But think about it. Manufacturers make hundreds of panel sizes but only a few box sizes.

So it's worth the legwork to see if the manufacturer can sell you a box with the guts you need that fit the same bolt pattern on the box you have wired-in.

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