Part of my job is to write procedures for vendors that perform work on their equipment. This prevents incorrect actions and unplanned events.

I have placed NFPA 70E verbage into the procedures and i ocasionally get the complaint that "this equipment will not facilitate me troubleshooting it with all that gear on. This equipment was designed before that standard and I have to troubleshoot it with long sleeves and safety glasses."

Some of the equipment has a hazard risk catagory of 3 or 4 and the technicians are checking communications and controls but they are within the boundary of the 480 volt hazard.

What have you been doing in these instances?

You are correct and they have to follow your procedures. And if something happens to a contractor on your facility you can be help liable, recently happened to IBM. I recommend using this pre-qual sheet for your vendors.