What does relay protection 221 represent

The SEL-221F Relay uses positive-sequence memory voltage polarized mho distance elements for phase and ground distance protection. These elements expand in proportion to the source impedance to provide more resistive fault coverage than self-polarized mho elements. VAMP 221 arc protection system components. Central unit VAMP 221. I/O units VAM 12L / VAM 12 LD, VAM 10L / VAM 10LD, VAM 3L / VAM 3LX and VAM 4C / VAM 4CRL / VAM 4CD 10 1. Arc sensors VA 1 DA, VA 1 EH, ARC SLx. Schneider Electric VAMP range is an arc flash detection and protection pioneer offering fast and reliable devices to improve safety. VAMP 221 significantly reduces the risk of potential personal damage, and material and production losses caused by arc fault. VAMP 221 complies with the latest standards concerning the. Serial communications ports allow local or remote interaction with the relay. 5” high chassis sizes. The report will identify methodology behind these practices, present issues raised by the integration of microprocessor relays and the internal logic and external communication configurations, ying. In the design of electrical power systems, the ANSI Standard Device Numbers denote what features a protective device supports (such as a relay or circuit breaker). [PDF]