Common use of Criteria for Permanent Blocking and Tripping Clause in Contracts

Criteria for Permanent Blocking and Tripping. The Merchant Transmission Facility system shall be permitted, but not required, to trip for the following extreme system conditions: Positive-sequence component of the fundamental frequency AC bus voltage at either the Xxxx 00xx Xxxxxx 345kV Substation 345kV AC bus or the Bergen 230kV AC bus greater than the upper limit or less than the lower limit as specified in Figure G-1. For the period up to 0.5 seconds, the upper voltage limit specified in Figure G-1 shall be applied to the greater of the fundamental-frequency positive-sequence AC bus voltage in pu on the nominal line-to-line rms voltage, the crest phase-to-ground voltage of any AC bus phase in pu of times the nominal line-to-line rms voltage, and the crest phase-to-phase voltage of any AC bus phase in pu of times the nominal line-to-line rms AC bus voltage. Negative-sequence component of the fundamental frequency AC bus voltage at either the Xxxx 00xx Xxxxxx 345kV Substation 345kV AC bus or the Bergen 230kV AC bus greater than the limits specified in Figure G-2. AC system fundamental frequency outside of the limits specified in Figure G-3. System conditions causing the AC system short-circuit capacity at the West 00xx Xxxxxx 345kV Substation 345kV AC bus to fall below 500MVA provided the AC system condition is not the result of the performance of the Merchant Transmission Facility. Figure G-2 Voltage imbalance (negative sequence component) threshold for permanent blocking and converter station tripping.