SEL-7203 panels provide advanced protection and control for distribution transformers with a single high-/low-side transformer zone boundary. These panels include the following features:
This module is always required and provides transformer differential and bus zone interlock protection using the SEL-787 Transformer Protection Relay, high-side breaker/circuit switching, motor-operated air break control, and sudden pressure tripping supervision. It also provides overcurrent through-fault and system backup protection using an SEL-751 Feeder Protection Relay and can perform direct transfer tripping if there is no local high-side interrupter.
This module is always required and provides redundant transformer differential protection, REF protection, overcurrent through-fault protection, and low-side breaker control and breaker failure protection.
If the station includes a bus-tie breaker, a version of the module that includes an SEL-751 breaker control relay is available. This relay provides breaker control with breaker failure, synchrocheck, and voltage monitor supervision. The tie breaker relay can also provide arc-flash protection if the buses are covered by arc-flash sensors.
This module provides independent local control and indication for up to four switching devices.
This module provides independent local control and indication for up to three switching devices using rotary switches.
This module provides independent mechanical lockout for the transformer protection (86T) and/or breaker failure protection (86BF) using rotary lockout switches.
The Firmware IDs for older versions of the firmware can typically be found in Appendix A of the instruction manual.