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Sub-Sub panel

Mark P

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An 1890 house that was converted to a duplex and now will be reconverted back to a single family home. There are two 100 amp main disconnects outside by the meters. In the basement there are two newer separate sub panels (one for each floor) with breakers, in which the Neutrals and grounds are separated. Seems everything is as it should be. Now the questions come. Down stream from each of these new sub-panels are old fuse sub-panels (a sub-sub panel) in which the Neutral/grounds are NOT separated. Since they are separated in the first sub panel is it okay? I don't believe these sub-sub panels are even needed. It seems they could be completely removed and replaced with a junction box.

My second question is when the house is changed back to a single family home, they will not want two meters with two separate bills and basic fees. The power company will remove one of the meters. Can they keep the two (100 amp) main disconnects with the separate sub-panels providing 100amps to each floor? Or would it be better to have a single 200 amps main installed while keeping the two sub-panels, servicing each floor?

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In question # 1 the answer is easy...NO, the connection between the grounded and grounding conductors on the same terminal buss should only take place at the main disconnection location for this dwelling, All additional remote distribution panels need to have seperation of the grounded and grounding conductors.

In question # 2 has many varibles....The best way to do this would be since most residential applications that are single family will only allow a single drop ( in your case ) and most POCO's only want a single meter location ( with expections ) the best thing to do would be to change the setup to a 200A meter can, redo the mast ( if overhead ) and have the 200A meter can feed the two exterior main disconnects which make these the grouped disconnection locations and then the remote distribution panels are fine....

Thats my opinion for what it's worth....

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