Since hiring in with this company, one of my "fill-in" projects is to install Type 2 TVSS on incoming utility power (and generator output) at a customer's sites. TVSS ans customer's specs call for the TVSS to be installed either at building disconnect or site transfer switch. The TVSS is usually 120/240 1ph, and calls for a #10 wire, although my predecessors have been using #6. My problem is HOW to connect the TVSS to the lugs on the disconnects or xfr switches. Most of these sites are 200A services, the disconnects are standard ones, with the incoming lugs almost surrounded by formed plastic/insulative materials, and rated at accepting a 350 or 500 kcmil wire. The generator lugs are just as large.
My problem is landing the TVSS conductors alongside with the installed conductors. right now, the SOP is to just back off the lugs and install the TVSS wires "on top of" the existing ones. I sure as heck don't like doing that, and one of the reasons for them hiring me was to minimize non-NEC installs just like this one. But so far, I have yet to come up with a satisfactory method of installing the wires, that meets all the other criteria I have to meet. Costs, mostly.
I can't replace the lugs with doubles, (won't fit without major reconstruction changing original construction), and although I've drilled and tapped small holes for control wire lugs, a lug the size necessary for a #10 or #6 is too large for a tapped hole in a manufacturer's installed lug (in my opinion).
Any suggestions? I'm really frustrated doing this jackleg style, but I can't find a better answer yet. There's just over 400 of these TVSS installed, or on Work Order to be installed, and they're a contract price, so nothing major can be changed.
Also, the sites are VERY dependent on power, with limited battery back-up time, so complete shut down is out of the question for anything longer than a short time.
