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· Registered
234 Posts
Discussion Starter · #1 ·
My garage is wired very interestingly. It goes from the panel (50A 240 breaker) with 6/3, then into a junction box where it is connected to 3/3 cable. That runs the length of the house, then into another junction box where it connects again to 6/3 cable. Finally, the 6/3 connects to 6/3 direct burial cable at the wall of the house and goes underground to my garage panel.

Wondering if this is legitimate (all connections are barrel connections with heat shrink over top)? I'm budgeting for an interior electrical job and wondering if I'm going to have to replace this all as well.

Ontario, Canada if it matters.


· Registered
10,395 Posts
The 3/3 section helps reduce voltage drop compared with 6/3 the full distance.

Voltage drop within any given piece of wire depends on the number of amperes passing through it at that moment and does not depend on whether a fat wire is first or in the middle or at the end of a run carrying the same amperes over its entire length.

· Master Electrician
194 Posts
It could be that way for voltage drop, could be just an attempt to use an existing cable that was buried. Certainly no issue with it as long as the breaker is sized on the smallest wire.

Running a larger wire in between two smaller wires is common when there is a long distance to cover. You don't normally see it in residential because the distances are generally shorter, unless you have a gate at the end of a long driveway or an out building several hundred feet away.


· Very Stable Genius
4,665 Posts
Thanks all.

The 3/3 is NMWU and the 6/3 is NMD90. The connection points are in 4x4x4 PVC junction boxes and as mentioned, made with barrel connectors covered in heat shrink.

They used smaller JB's than allowed. Personally, now that it's done, I'd
leave it alone. Working out the correct min JB size would require more
info regarding the side of the box each cable enters. Straight through
actually requires larger box than adjacent sides, and entering the box
through the side opposite the cover is different again.
Code ref 12-3036
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