S5750E Series Installation Guide
Chapter 2 Device Installation
2-2
avoid harmful gases, such as SO
2
, H
2
S, NO
2
, NH
3
and Cl
2
, etc. The table below details the
threshold value.
Table 2-2 Environmental Requirements: Particles
2.1.1.2 Temperature and Humidity
Although the switch is designed to use fans, the site should still 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. In the hot summer, it is recommended to use
air-conditioners to cool down the site. And the cold winter, it is recommenced to use
heaters.
The recommended temperature and humidity are shown below:
Table 2-3 Environmental Requirements: Temperature and Humidity
Caution!
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.