SPGS' Equipment Shelf Isolation Kit is designed to isolate a conductive equipment shelf from a conductive equipment frame by isolating each mounting hole position from the equipment frame. This isolation is needed to isolate a faulted equipment shelf (ground loop, objectionable current) from a non faulted equipment frame within any required grounding system that does not permit objectionable current flow on metallic equipment frames. Our kit includes a metallic screw with a nylon sleeve and washers which offers lasting mounting versus a full nylon shelf isolation kit which is prone to breaking after being in a low humidity environment.
The National Electrical Code (NEC) 2017 Article 250.6 Objectionable Current over Grounding Conductors gives methods of preventing these objectionable currents. The Equipment Shelf Isolation Kit is one of the alterations acceptable methods, by the NEC, to stop the objectionable current flow. Using our Equipment Shelf Isolation Kits and properly verifying the shelf grounding is usually the most cost effective methods of eliminating the objectionable current.
When objectionable current flow is present on metallic framework it creates shock hazards for all personnel. This objectionable current flow has the probability to cause other electrical devices to fail at random and/or perform unsatisfactorily during normal operating conditions. Ground loops have been known to cause total or major equipment outages during power surges and lightning strikes.
The Equipment Shelf Isolation Kit only isolates one mounting hole in the metallic equipment shelf. If the metallic equipment has four (4) mounting holes then four (4) Equipment Shelf Isolation Kits would be required.