BS 7494-1:1991

Committees responsible
Foreword
Section One - General
1. Scope
2. Object
3. Service conditions
3.1 Ambient conditions
3.2 Supply voltage with battery operation
3.3 Supply voltage with a.c. mains operation
3.4 Storage conditions
4. Telecommunication circuit used
Section Two - Terminology
5. Terminology
Section Three - Definitions of teleprotection systems
6. General
7. Types of teleprotection schemes
8. Overall operating time of teleprotection systems
     (telecommunication circuit included)
9. Transmission time (telecommunication circuit
     excluded)
10. Security
11. Dependability
12. Nominal frequency band
13. Nominal impedance
14. Guard - Command signals
15. Levels of guard signals
16. Levels of command signals
Section Four - Requirements
17. General equipment interface requirements
17.1 Insulation
17.2 Impulse withstand level
17.3 High-frequency disturbance level
18. Specific power supply requirements
18.1 Power supply variations
18.2 Interruptions
18.3 Reflected noise
18.4 Reverse polarity
19. Requirements for the teleprotection system
     performance
19.1 Interrelationship of requirements
19.2 Monitoring and alarms
Section Five - Methods for performance testing
20. General equipment interface tests
20.1 Insulation
20.2 Impulse withstand level
20.3 High-frequency disturbance level
21. Specific power supply tests
21.1 Power supply variations
21.2 Interruptions
21.3 Reflected noise
21.4 Reverse polarity
22. Teleprotection system performance tests
22.1 Security
22.2 Dependability
22.3 Transmission time
22.4 Interference by discrete frequencies
22.5 Interference by frequency deviation
22.6 Checking alarm functions
22.7 Multicommand equipment
22.8 Additional tests
Appendices
A. Supplement to Clause 22: Teleprotection system
     performance tests
B. Bibliography
Z. (untitled)
Figures

Applies to narrow-band single-signal and multisignal equipment for teleprotection. Also applies to voice frequency equipment which is used in connection with various telecommunication systems, such as power line carrier, radio link, rented circuits, leased or owned cables.

This standard applies to narrow-band single-signal and multi-signal equipment for teleprotection.

It also applies to voice frequency equipment which is used in connection with various telecommunication systems, such as power line carrier (PLC), radio link, rented circuits, leased or owned cables.

Narrow-band systems include audio frequency systems operating within a 4 kHz maximum band, and PLC channels within a maximum of 4 kHz bandwidth (for one direction of transmission).