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SEL manufactures high-quality cables for connecting a variety of devices. You can order cables to specific lengths to meet your needs. Each cable is quality tested to ensure reliability and proper operation.
This application guide explains how to calculate the time to reset after a thermal lockout condition. Use the accompanying spreadsheet to calculate the reset time based on relay settings and load current. This can be used to verify if the thermal model settings are compatible with the operational requirements of the motor.
This application guide explains how to use a script to easily update the firmware on one or more SEL-3610, SEL-3620, or SEL-3622 devices.
This application guide describes an RTAC implementation of DF1, a robust but simple serial-line protocol that can read and write data from and to an Allen-Bradley PLC. The protocol is implemented with the use of an acSELerator RTAC extension package. Use of the DF1 protocol eliminates the requirement for third-party hardware and programming to connect the SEL RTAC and Allen-Bradley and Rockwell systems.
This application guide explains the working and testing procedure of the high-speed mho distance elements available in the SEL-421 Relay and SEL-411L Relay. Use the accompanying spreadsheet to calculate test points for different fault types.
This application guide helps you calculate transformer thermal-model cooling constants to obtain an accurate winding temperature as well as apply those constants to SEL terminology. It also includes a thermal model testing section for initial field commissioning.
This application guide demonstrates how to simulate concurrent fast and delay curves in the SEL-651R similar to those in the SEL-351R Recloser Control. This provides some advantages in certain applications, such as interfacing with the SEL-FT50 and SEL-FR12 Fault Transmitter and Receiver System and second-harmonic blocking. A sample design template is included that incorporates the concurrent curve method.
Application Guide - In a main and transfer bus arrangement, the bypass breaker can be used to take a line breaker out of service and maintain system integrity. However, the performance of the protective system is degraded if the communications circuit is not rerouted to the bypass breaker protection.
Application guide - The SEL-121F, SEL-121S, SEL-121-0, SEL-221F, SEL-221S, and SEL-221-16 Relays were designed in the 1980s and include phase and ground distance elements. There is not enough processing power in an eight-bit microcontroller to check all of the distance elements (AB, BC, CA, AG, BG, and CG) for each zone during every one-quarter-cycle processing interval. Therefore, these relays use a method for faulted phase identification that is described in this application guide.
Application Guide - This application guide demonstrates steady-state, single-phase testing of the SEL-487E Transformer Protection Relay differential element and does not require state simulation. For a complete reference on testing this relay, refer to SEL Application Guide AG2010-07 .
This application guide shows how to reduce effort and complexity when performing common device management tasks (such as upgrading firmware) for the SEL Real-Time Automation Controller (RTAC).