3 Phase equipment is included in the IET Code of Practice (4th Edition) & therefor should be treated the same as any single phase appliance carrying out visual, earth bond & insulation tests. Connections can be made to the PAT tester using 3 phase adapters, should you wish to carry PE Conductor Current tests or Touch Leakage Tests on 3 phase equipment then you need to ensure your tester has the capability to do so or have the appropriate leakage test adapters.