2-4
Gas
Maximum concentration (mg/m3)
Cl
2
0.01
Anti-static Requirements
Any possible interference sources, no matter outside or inside the system, affect the switch in use may
in a way of capacitance coupling, inductance coupling, radiation of electromagnetic wave, common
impedance (including the grounding system) coupling or conducting line (power line, signaling line and
transmission line etc.).Therefore, the following should be considered:
z
Adopt effective measures to protect the power supply system against the power grid interference.
z
Separate the working ground of the switch from the ground device of the power supply equipment
or lightning-protection ground device as far as possible.
z
Keep the switch far away from the radio launcher, radar launcher, and high-frequency devices
working in high currents.
If necessary, adopt electromagnetic shield.
Grounding Requirements
A good grounding system is the basis for a switch to work stably and reliably and the important
guarantee of lightning protection, anti-interference and ESD. A user should provide good grounding
system for the switch and the grounding resistance should be less than 1.5 ohm.
Power Supply Requirements
For the power supply requirements, refer to section 1.2.3 “Power Supply System” in Chapter 1 “Product
Overview”.
Installation Planning
Since the S7900E series are a kind of complex equipment, it is necessary to make a good plan and
arrangement concerning installation position, networking mode, power supply and cabling before
installation.
Installation Space Requirement
For better heat dissipation and equipment maintenance, it is recommended that the front and back of
the switch should be at least one meter away from walls or other devices, and that the left and right of
the switch should be at least 0.8 meters away from walls. If a rack is to be installed, the headroom
should be 3 meters at least.
If the above-mentioned requirements are not satisfied, it will be very inconvenient to install a rack or
install air filters on the switch.
Rack-Mounting Requirements
Before rack-mounting a switch, make sure the rack meets the following requirements:
z
Better mount a switch in an open rack. However, if you mount a switch in a closed rack, make sure
of good heat dissipation system.
z
Make sure the rack stands steadily enough to well support the switch and accessories.
