National Electrical Code does allow metallic conduit and tubing to be used as an equipment grounding conductor, as long as it's installed properly. However, before using it as such in an existing installation, you should verify that it provides an adequate continuous path to ground. Rigid metal conduit, intermediate metal conduit and electrical metallic tubing are permitted in 250. 118 (2), (3) and (4) respectively. Learn five techniques for fast, accurate power rail integrity measurements—reduce noise, add offset, analyze EMI, and speed testing with the right scope, probe, and settings. Article 314 applies to: These.