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Myers Hub Problem

  Myers HUBs that have a nut without a bonding screw are causing problems for installers. These type of HUBs are called "Conduit Fittings" and are not approved for grounding and bonding in most applications. These types of HUBs are not evaluated for grounding but are evaluated for continuity using about 30 amperes of current. A "Grounding HUB" of 3 inch size is tested for 5000 amperes for 9 seconds - quite a difference!! And the only difference in the two HUBs is a bonding screw. The one with the bonding screw that is evaluated to UL standard 467 is approved for bonding at services, bonding of raceways containing circuits of over 250 volts to ground, and for bonding of raceways in hazardous locations provided the HUB is approved for the location. All this has been checked out with UL and can be read about in the UL Green Book or White Book.

© 1996 Gerald Newton. All rights reserved.