enter image description hereThis is a tri-plex in central washington with outdoor fuse panels where I plan to use a multi meter pack and install outdoor 125 amp panels. I found another post titled "How do I convert a service panel to a junction box?". It answers most of my questions except for how I would run conduit and details on how to connect the wires.

The fuse panels are flush with the exterior siding and have hinged access doors. Can I cut holes in the doors and attach conduit? Screw the doors shut when complete?

Should connection of 10ga or bigger be done w split bolts and wire nuts for 12-14ga? How much free length of wire is required in the j box?

  • 1
    Can you get us measurements and photos of the existing fuse panels please? Mar 10, 2022 at 12:43
  • Tri-Plex implies renting out two (or all three) implies you can't legally DIY electrical work on that.
    – Ecnerwal
    Mar 10, 2022 at 13:55
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    It would only be legal for owner to do the work if family resides in the units, father, mother brother, sister ETC. AFAIK this is the only exception, Oregon and Washington have reciprocal agreements so our laws are similar. If the boxes were used as j boxes they still have to be accessible and you can use tools but must be able to open them. Last check out Polaris connectors, All the big box stores have them they are pre insulated, put the wire in and lock down a hex / Allen set screw on the wire (of corse using a torque driver) better than split bolts they cost a few bucks easier than tape
    – Ed Beal
    Mar 10, 2022 at 15:07
  • My son resides in one unit. AHJ says I can do it. The fuse panels are 10"x17". Looking closer at the fuse panes, they have small doors so my original question about "conduit through the doors" is a bad idea.
    – jasowiii
    Mar 10, 2022 at 17:19

1 Answer 1


If the instructions/labeling say you can.

The enclosures do (or did) have labeling and instructions. When UL approves equipment, they approve the labeling and instructions as part of the UL listing. These define how you are allowed to use the equipment (because, that is what UL tested for). NEC, in turn, requires you follow them.

So the answer is, you can make a front entrance if the enclosure's documentation says you can. I note two of the enclosures already have front entrances, and they have double-hinged covers which appear to be designed for that purpose.

I have never been a fan of "set-in-the-wall" enclosures, and this kind of thing is the reason why.

The modern trend is "Meter-Mains", where the unit main breaker is at the meter. This is increasingly required for fire department access, and is a NEC 2020 requirement. At that point, the panel for a particular unit can be inside the unit, and does not need to be outside.

Note that it is a Code requirement that every tenant be able to access all their own breakers. Nothing says you can't put a lock on it (e.g. to reduce vandalism) but the tenant must have a key. (the Fire Department has a "key").

  • I'll look for labeling but theses panels were installed in 1928. Doubtful that documentation can be located.
    – jasowiii
    Mar 11, 2022 at 5:59

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