UNE-EN 61643-321:2003

1 Scope
2 Normative references
3 Definitions and symbols
4 Basic function and description for ABDs
5 Service conditions
6 Standard test methods and procedures
   6.1 Standard design test criteria
   6.2 Test conditions
   6.3 Clamping voltage V[c] (see figure 2)
   6.4 Rated peak impulse current I[PPM] (see figure 2)
   6.5 Maximum working voltage V[WM] and maximum working
        r.m.s. voltage V[WM[rms]] (see figure 3)
   6.6 Stand-by current I[D] (see figure 3)
   6.7 Breakdown (avalanche) voltage V[BR] (see figure 4)
   6.8 Capacitance C [j]
   6.9 Rated peak impulse power dissipation P[PPM]
   6.10 Rated forward surge current I[FSM] (see figure 1c)
   6.11 Forward voltage V[FS]
   6.12 Temperature coefficient of breakdown voltage alpha
        V[BR]
   6.13 Temperature derating (see figure 5)
   6.14 Thermal resistance R[thJA] or R[thJC] or R[thJL]
   6.15 Transient thermal impedance Z[thJA] or Z[thJC] or
        Z[thJL]
   6.16 Rated average power dissipation P[MAV]
   6.17 Peak overshoot voltage V[OS] (see figure 7)
   6.18 Overshoot duration (see figure 7)
   6.19 Response time (see figure 7)
7 Fault and failure modes
   7.1 Degradation fault mode
   7.2 Short-circuit failure mode
   7.3 Open-circuit failure mode
   7.4 "Fail-safe" operation
Annex ZA (normative) Normative references to international
         publications with their corresponding European
         publications
Figures

Applies to avalanche breakdown diodes (ABDs) which represent one type of surge protective device component (hereinafter referred to as SPDC) used in the design and construction of surge protective devices connected to low-voltage power distribution systems, transmission, and signalling networks.