enter image Main Panel Fused SHutoff between main panel and meeter Meter I want to upgrade my load centre panel that currently has a 100 amp main breaker w to 200 amp one along with the 100 amp service shutoff. The main is about 20' from the inside 100 amp fused shutoff connected with NMD-7 3/3. The meter base is outside on the opposing wall of the shutoff and is rated 200 amp. The shutoff and meter base are connected via conduit so i can't easily see the wire gauge. Do i need to replace the NMD-7 3/3 wire? Can i replace the main panel with a 200 amp and change the 100 amp service shutoff at a later date?

  • Welcome to StackExchange. I'm a little confused. Are you saying the service shutoff is between the meter pan and the main panel (electrically)? Does it have overcurrent protection at 100A? Breaker or fuses? I am also unclear on your endgame goal. Are you aiming to increase your usable electrical service to 200A, or just like 200A sized panels? (We do too :) Aug 16, 2018 at 19:24
  • The breaker panel with 100 amp main is on an inside wall in the cottage due to an addition, It is protected on the other side of the room with a 100 amp fused shutoff which is connected via conduit the outside meter just behind it. The panel has 24 breakers and is full. no room for expansion, tight and a rats nest. I have some immediate plans to do some renovations and add a couple of 15 amp circuits bathroom/bedroom. I likely don't have to go to 200 amps but none of the bedrooms have any heat source at this time.
    – Clay
    Aug 16, 2018 at 21:42
  • If i every want to make it 4 season i'd likely put those in sometime in the future hence i am thinking of putting in a 200 amp panel. Maybe my best bet is to install a 200amp panel downgrade the main to 100 amps and hold on to the 200 for the future, Or can i just leave the 200 main breaker in the new panel for now knowing the 100 amp fused shutoff will protect an overload scenario -- is that allowed according to code. Hope that helps.
    – Clay
    Aug 16, 2018 at 21:42
  • Where are you on this planet, and what is this NMD-7 cable you're seeing? Aug 16, 2018 at 22:13
  • 1
    Wonderin' aboot his location, eh? Aug 16, 2018 at 22:35

1 Answer 1


You can use a 200 A panel with 100 A service with no problem; it's done quite regularly. You can just put a 100 A main breaker on it (saving the 200 A one it may have come with for later). A lot of times the 200 A panels are cheaper, have more slots, and/or are just physically bigger (easier to work in), which is why they are used even if the service is less than 200 A.

  • Ontario, Canada
    – Clay
    Aug 17, 2018 at 11:52
  • Ontario, Canada. The NDM-7 3/3 runs from the inside fused shutoff to the main load centre panel on the other side of the room.
    – Clay
    Aug 17, 2018 at 11:54

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