49
z
Make sure the rack or workbench is well grounded; if the workbench is not
grounded, it should be placed near a grounding conductor to provide easy
ground connection for the switch.
2.1.2 Temperature and Humidity Requirements
To maximize the switch’s performance and lifespan, the site should maintain a
desirable temperature and humidity. High-humidity conditions can cause electrical
resistance degradation or even electric leakage, degradation of mechanical properties
and corrosion of internal components. Extreme low relative humidity may cause the
insulation spacer to contract, making the fastening screw insecure. Furthermore, in dry
environments, static electricity is liable to be produced and cause harm to internal circuits.
Temperature extremes can cause reduced reliability and premature aging of insulation
materials, thus reducing the switch’s working lifespan. The recommended temperature
and humidity are shown below:
Temperature: Relative
humidity
Long term condition Short term condition Long term condition Short
term
condition
15 ~ 30°C
0 ~ 40°C
40
～
65% 10
～
90%
A sample of ambient temperature and humidity should be taken at 1.5m above the
floor and 0.4m in front of the switch rack, with no protective panel covering the front and
rear of the rack.
Short term working conditions refer to a maximum of 48 hours of continued operation
and an annual cumulative total of less than 15 days.
Formidable operation conditions refers to the ambient temperature and relative humidity
value that may occur during an air-conditioning system failure, and normal operation
conditions should be recovered within 5 hours.
2.1.3 Dust and Particles
Dust is harmful to the safe operation of the ES4700BD. Dust can lead to electrostatic
adherence, especially likely under low relative humidity, causing poor contact of metal
connectors or contacts. Electrostatic adherence will result in not only reduced product
lifespan, but also increased chance of communication failures. The recommended values
for dust content and particle diameter in the site are shown below:
Notice