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Myers Hub Problem
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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.
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© 1996 Gerald Newton. All rights reserved.
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