• CCITT Rec. K.20 (11/1988) – RESISTIBILITY OF TELECOMMUNICATION SWITCHING EQUIPMENT TO OVERVOLTAGES AND OVERCURRENTS
  • 1 General
  • 2 Scope
  • 3 Overvoltages and overcurrent conditions
  • 4 Levels of resistibility
  • 5 Exchange equipment boundary
  • 6 Test conditions
  • 7 Permitted malfunction or damage
  • 8 Tests
    • 8.1 General
    • 8.2 Unexposed environment
    • 8.3 Exposed environment
  • ANNEX A (to Recommendation K.20) – Explanations which illustrate test conditions
    • A.1 Lightning surges
      • A.1.1 Operation of simulation circuit
      • A.1.2 Effect of protective devices
    • A.2 Power induction
    • A.3 Power contacts