US 12,444,926 B2
System and method for eliminating nuisance fuse operation associated with medium voltage distribution transformers
Marshall Mauney, Kemah, TX (US)
Assigned to S&C Electric Company, Chicago, IL (US)
Filed by S&C Electric Company, Chicago, IL (US)
Filed on Dec. 14, 2022, as Appl. No. 18/080,824.
Claims priority of provisional application 63/301,826, filed on Jan. 21, 2022.
Prior Publication US 2023/0238796 A1, Jul. 27, 2023
Int. Cl. H02H 7/22 (2006.01)
CPC H02H 7/22 (2013.01) 7 Claims
OG exemplary drawing
 
1. A system for protecting electrical distribution networks, comprising:
a plurality of intelligent, self-powered current interrupting devices, each configured to be installed at a distribution transformer and at a lateral line connection;
wherein each current interrupting device includes a programmable controller configured to:
detect overcurrent conditions;
operate within a predetermined time-current characteristic curve, wherein the interrupting device at the distribution transformer is configured to interrupt current within one cycle or less, and the interrupting device at the lateral line is configured to interrupt current after a delay of approximately two cycles;
automatically reclose after a predefined interval following a temporary fault;
a surge arrestor positioned downstream of the distribution transformer interrupting device; and
wherein the system is configured to prevent nuisance operations by coordinating the timing of the interrupting devices to ensure that the distribution transformer interrupting device operates prior to the lateral line interrupting device during fault conditions.