QSW-6200
Series Switch Hardware Installation and Reference Guide
28
www.qtech.ru
2.2.5 Lightning Resistance
When the AC power cable is imported outdoors and directly connected to the power port of the switch, lightning
preventing wires should be adopted to prevent the switch from being hit by lightning shocks. The lightning preventing
wires can be fixed on the cabinet, work station, or the equipment room
’s wall through line buckles and screws. In
applications, the AC current first enters the lightning preventing wires and then the switch.
The lightning preventing wires are not provided and should be purchased by users as required. For the usage of
lightning preventing wires, refer to their manuals.
2.2.6 EMI
All kinds of interference, from inside or outside of the device or application system, create impacts on the device by
transmission of capacity coupling, inductance coupling and electromagnetic waves.
Electromagnetic interference can be divided into two categories by transmission types, namely i.e. radiated interference
and conducted interference.
Power, normally RF power, transmitted from a device through space to a sensor is called radiated interference. The origin
of the interference source can either be part of or a unit separated electrically from the interfered system. Conducted
interference is transmitted through magnetic wires or signal cables from the source origin to sensors. Generally,
conducted interference affects the power supply of a device and can be controlled by a wave filter. Given that radiated
interference can interrupt any signal paths of the device, it is difficult to shield the device from such interference.
The AC power supplying system is the TN system. The single-phase three-wire socket with protecting grounding
must be used as the socket for the power supply to enable
the device’s upper filter circuit to effective filter the
power interface.
The switch should be far from high-power radio transmitting stations, radar stations and high-frequency and
large-current devices.
Electromagnetic shielding methods should be applied when necessary, such as using the shielded cable as the
interface cable.
Cables must be connected to interfaces inside the room to prevent damage to the device’s signal ports caused
