YDN 127-2005
Safety criteria for telecommunication equipment (English Version)

Standard No.

YDN 127-2005

Language

Chinese, Available in English version

Release Date

2005

Published By

Professional Standard - Post and Telecommunication

Latest

YDN 127-2005

Scope

This standard applies to telecommunications network equipment that is powered by the grid, battery-powered or remotely powered. This standard is intended to reduce the risk of fire, electric shock or other injury to operators and non-professionals who may come into contact with the equipment. When special instructions are given, it also applies to maintenance personnel. This standard is intended to reduce hazards when installation, operation and maintenance are performed in accordance with the methods specified in the equipment instructions or technical documents. A device can be a system composed of several interconnected device units, or it can be a system composed of several independent devices. Equipment that meets the relevant requirements of this standard can be used on telecommunications networks. This standard does not include requirements for equipment performance or functionality. For the following equipment, additional requirements may be required in addition to the safety requirements specified in this standard: 　——In special environments such as extremely high or extremely low temperatures, excessive dust, high humidity or severe vibration, flammable gases, corrosion or explosions Equipment that works under conditions; 　——Equipment used on vehicles, ships or aircraft, equipment used in tropical areas or plateau areas above 2000m above sea level; 　——Equipment used in situations where water may enter. Telecom systems powered by the network are systems that use pairs of cables in the network or specific feeder cables to provide power to remote devices. Maintenance personnel may touch these devices and current-carrying cables without using insulating gloves or tools. For telecommunications systems powered by the network. This standard specifies safe limits for operating voltage and operating current through the system. This kind of system is not installed on the user side, and the system is not accessible to network users. This kind of system is located on the network between different telecom centers and between the interfaces between telecom centers and the public network. Figure 1 shows the situation where this system is located between different telecom centers, and Figure 2 shows the situation where this system is applied to the access network. If there is no access network equipment between the local exchange and customer premises equipment, the safety limits for operating voltage and operating current of telecommunications systems powered through the network do not apply. For telecommunications systems powered through the network, this standard only covers systems powered by continuous DC sources.

YDN 127-2005 history

• 2005 YDN 127-2005 Safety criteria for telecommunication equipment