I've been looking at the NEC 2005 Handbook, Section 590.6. I am curious if under section 590.6(B), Use of Other Outlets, the NEC intended to include 480V connections? - they aren't specifically excluded... My background is more from an OSHA perspective, where GFCI's are required for temporary power installations in construction. OSHA currently does not require GFCI use on 480V connections.