Just a few easy questions before I start my wiring......

Once you have the transformers in phase, you are good to go with that scheme.

If the loops are truly completely independent and you plan to keep them that way, phasing doesn't matter. In situations with very high current loads, it's actually beneficial for transformers sharing a common return to be out of phase(it requires a much smaller gauge common wire which otherwise needs to be sized to carry the load of the sum of all power supplies).

Did I read in your post that you are planning on using bare wire not only for your neutral, but also for your Hots?  I would suggest you use jacketed wire for your Hots.  Seems like to great a possibility to have shorts occur.

I would also suggest that the Hots be 14 gauge and Stranded,  You are not going to save any green but 14 ga. stranded is much easier to string under the table than 12 ga. solid (If you were planning on using solid).

Loose-Caboose posted:

Did I read in your post that you are planning on using bare wire not only for your neutral, but also for your Hots?  I would suggest you use jacketed wire for your Hots.  Seems like to great a possibility to have shorts occur...

I agree. but it sounds like it's already strung out as described.

Loose-Caboose posted:

Did I read in your post that you are planning on using bare wire not only for your neutral, but also for your Hots?  I would suggest you use jacketed wire for your Hots.  Seems like to great a possibility to have shorts occur.

I would also suggest that the Hots be 14 gauge and Stranded,  You are not going to save any green but 14 ga. stranded is much easier to string under the table than 12 ga. solid (If you were planning on using solid).

I went with 14ga. romex for the + runs and 12ga.solid for the common(-).  I stripped the insulation off and stapled them under the benchwork with discrete spacing between so no shorts would occur. Been that way for decades without problems.

Rich since you are running two independent loops with two separate transformers,  what is your reasoning for connecting the commons together?  If you run separate commons phasing isn't an issue.  Are you trying to save $ on the bare copper wire?  It  just seems unorthodox to do it that way. 

wild mary posted:

...If you run separate commons phasing isn't an issue...

If the loops are truly completely independent and the plan is to keep them that way, phasing doesn't matter even with a shared return/common. One of the power supplies could even be DC, like from a power pack or deep cycle battery.

Yes, the bus lines are installed already.

Wild Mary-  Granted the cost for the fourth loop would be insignificant but just another set of holes to be drilled, more time dragging wire thru holes above my head. I figured the shared common save some install time. Looking back, I probably would have gone the stranded wire route for the hot bus. That solid wire is a pain to pull! I was at least smart enough to start inserting the wire in a hole that was in the middle of the run and that way I pulled half the wire length in opposite directions back to the transformer.

Loose Caboose-  Regarding potential shorts to the hot bus, I drilled my holes with that in mind (the table is of the "L" girder style of construction), I'll  finish up with some wire clamps to keep the wire against the underside of the plywood. I don't see any thing happening that would cause shorting.

ADCX Rob- I'll just jumper the "U" terminals and won't worry about phasing.

Thank you very much everyone for your replies!