Usage and application scopeUsage and application scope of BY10 type surge protective device (short name "SPD") is suitable for AC 50/60 Hz,380V and the following electric power systems,such as TT, IT, TN-S, TN-C, TN-C-S. It protects the electric network shocked by the thunder or over voltage .Working condition:  1.Height: not more than 2000m   2. Operating temperature : normal -5~+40C Enlarge range: -40~+80C  3. Relative humidity: on condition that room temperature 30%~90%  4. Installed at no notability shocked and virated place  5. Don't be contained in explosion medium,the medium such as air and dust (including conduction dust ) shouldn't come to the degree that can corrode metal or damage insulation.