NB/T42150-2021低压电涌保护器专用保护装置英文版(4)

This standard applies to specific protective devices for low-voltage surge protective devices in systems with AC frequency of 50Hz or 60Hz, and rated voltage not exceeding 440V (phase to phase), hereinafter referred to as the “specific protective device” or “SSD”.
Note: This standard may apply to specific protective devices for the surge protective devices (SPDs) intended for AC rated voltage not exceeding 1000V (rms) or DC voltage not exceeding 1500V.
For the purposes of this standard, the specific protective devices are mainly based on circuit breaker technology and are suitable for overcurrent protection of voltage-limiting SPDs.
The specific protective devices covered by this standard are suitable for isolation.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB/T 4208-2017Degrees of protection provided by enclosure (IP code)