SIPROTEC 7SJ45 easy- Numerical Overcurrent Protection Relay Powered
Description
The SIPROTEC easy 7SJ45 is a numerical overcurrent protection relay which is primarily intended as a radial feeder or
transformer protection (backup) in electrical networks. It provides definite-time and inverse-time overcurrent protection
according to IEC and ANSI standards. The 7SJ45 relay does not require auxiliary voltage supply. It imports its power supply
from the current transformers.
Function overview
• Operation without auxiliary voltage via integrated CT power supply
• Standard current transformers (1 A/5 A)
• Low power consumption: 1.4 VA at IN (of the relay)
• Easy mounting due to compact housing
• Easy connection via screw-type terminals
Protection functions
• 2-stage overcurrent protection
• Definite-time and inverse-time characteristics (IEC/ANSI)
• High-current stage I>> or calculated earth-current stage IE> or IEp> selectable
• Trip with pulse output (24 V DC / 0.1 Ws) or relay output (changeover contact)
• Repetition of trip during circuit-breaker failure (relays with pulse output)
• Combination with electromechanical relays is possible due to the emulation algorithm Monitoring functions
• Hardware and software are continuously monitored during operation Front design
• Simple setting via DIP switches (self-explaining)
• Settings can be executed without auxiliary voltage – no PC
• Integrated mechanical trip indication optionally
Additional features
• Optional version available for most adverse environmental conditions (condensation permissible)
• Flush mounting or surface (rail) mounting
The SIPROTEC easy 7SJ45 is a numerical overcurrent protection relay which is primarily intended as a radial feeder or
transformer protection (backup) in electrical networks. It provides definite-time and inverse-time overcurrent protection
according to IEC and ANSI standards. The 7SJ45 relay does not require auxiliary voltage supply. It imports its power supply
from the current transformers.
Function overview
• Operation without auxiliary voltage via integrated CT power supply
• Standard current transformers (1 A/5 A)
• Low power consumption: 1.4 VA at IN (of the relay)
• Easy mounting due to compact housing
• Easy connection via screw-type terminals
Protection functions
• 2-stage overcurrent protection
• Definite-time and inverse-time characteristics (IEC/ANSI)
• High-current stage I>> or calculated earth-current stage IE> or IEp> selectable
• Trip with pulse output (24 V DC / 0.1 Ws) or relay output (changeover contact)
• Repetition of trip during circuit-breaker failure (relays with pulse output)
• Combination with electromechanical relays is possible due to the emulation algorithm Monitoring functions
• Hardware and software are continuously monitored during operation Front design
• Simple setting via DIP switches (self-explaining)
• Settings can be executed without auxiliary voltage – no PC
• Integrated mechanical trip indication optionally
Additional features
• Optional version available for most adverse environmental conditions (condensation permissible)
• Flush mounting or surface (rail) mounting
