Tap Rules Applicable?

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gman2000

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Huntsvile, AL
Scenario is installing factory-assembled electronic meter enclosures. Much like most industrial control panels, they have an internal fused disconnect with FNQ-R Class CC fuses rated at 200KAIC which covers almost all possible install locations. They also have an internal shorting block. We know from NEC 230.82 that a meter or meter disconnect is allowed to be connected to the supply side of a service disconnect. Being a second meter in addition to any existing utility meter, the meter enclosure could be immediately adjacent to a main switchboard or up to 25 feet or so (in conduit/wiring) away, depending on wall space. I have had several locations where someone will insist that the meter installation has to comply with 240.21 tap rules, in some cases wanting to require a voltage fuse block and sometimes a CT shorting block in or attached to the switchboard enclosure. I have always contended that metering, by virtue of its being addressed in 230.82, is not technically a branch circuit and therefore not subject to tap rules. Am I correct?
 
Voltage Taps for Metering

Voltage Taps for Metering

I know that when obtaining voltage for metering from busbars that any existing holes must be marked "TAP" in order to utilize them for voltage taps. Moreover, since drilling a busbar voids UL listing, that would require UL re-certification. Many times there are no existing tap holes nor existing breaker or space for one to obtain metering voltage. I also know that usually a mechanical lug is supposed to be rated for more than one conductor to utilize it that way. I have normally seen utility providers and many others obtain metering voltage feed by sandwiching the conductors under service conductors in the mechanical lug. Is this permissable, or shouldn't it be, provided the smaller metering voltage wiring is securely connected and not subjected to damage by gross deformation like what would happen if the lug screw were run down on it?
 
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I bumped and merged these threads as they are related and have not yet been addressed
 
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