Explain the differences between Horn Bypass, Lever Bypass and Test Block Bypass as used in meter equipment.
MP and EZM Metering Equipment
Electrical Distribution Equipment
The different types of meter sockets are confusing. What is the difference?
Horn Bypass is available for use with ringless style, single phase out, metering equipment and requires the use of utility supplied jumper cables that may be installed once the outer ringless cover is removed from the meter socket. Short bus connectors extend upward from the line side and downward from the load side meter socket jaws. The ends of these bus connectors give the appearance of "Horns". One jumper cable per phase is manually installed by a qualified service technician creating a path for current to flow once the meter is removed from the socket. This temporary bypass feature allows the utility to perform meter MAINTENANCE without interruption of service to the downstream occupant.
Lever Bypass is available for use with ringless style single or three phase metering equipment and is supplied with a swing arm or "Lever" extending form the right side of the meter socket. Once the ringless meter socket cover is removed, this dual function Lever may be manually rotated upward to engage bypass rotor blades into line and load bypass jaws allowing current to flow through the meter socket with the meter in or out of the meter socket. The second feature this Lever provides is a jaw release function. By rotating the Lever up as far as possible the spring loaded meter socket jaws are spread open for ease of meter installation or removal. This temporary bypass feature allows the utility to perform meter MAINTENANCE without interruption of service to the downstream occupant.
Test Block Bypass is available for ring style single or three phase metering equipment and was developed for use along the West Coast governed by the Electrical Utility Service Equipment Requirements Committee (EUSERC). Trained service technicians perform meter MAINTENANCE while this equipment remains energized and while their meter remains installed in the ring style meter socket. The "Test Block" cover is removed and the technician manually installs a set of jumpers extending from the line to load side connectors feeding to and from the meter being tested. Once the jumpers are in place, bronze current carrying flat washers are removed from each phase and at this point the meter bypassed, or isolated from the circuit. This temporary bypass feature allows the utility to perform meter MAINTENANCE without interruption of service to the downstream occupant.