Checking The Installation Site; Temperature And Humidity Requirements; Cleanliness - H3C WIRELESSACCESSCOTROLLER S7500E Installation Manual

Plug the grounding terminal of the ESD-preventive wrist strap into the ESD-preventive wrist strap jack
on the switch chassis, or attach the ground wire of the ESD-preventive wrist strap to the grounding
screw on the chassis with an alligator clip.
Verify that the ESD-preventive wrist strap is well grounded.
For the safety purpose, check the resistance of the ESD-preventive wrist strap, which should be
between 1 to 10 megohm.

Checking the Installation Site

The installation environment for the access controller module must meet the requirements described in
this section.

Temperature and Humidity Requirements

Proper temperature and humidity must be maintained in the equipment room. Lasting high relative
humidity tends to cause poor insulation, electricity creepage, mechanical property change of materials,
and corrosion of metal parts, while lasting low relative humidity can result in loose screws due to washer
contraction, and even electrostatic discharge (ESD) that will cause the complementary
metal-oxide-semiconductor (CMOS) circuitry to fail. A proper temperature condition must also be
maintained to prevent premature material aging and degraded reliability accompanying high
temperature conditions.

Cleanliness

Dust is hazardous to the operation safety of the access controller module. Dust buildup on the chassis
may result in static adsorption, causing poor contact of metal components or contact points. When the
relative indoor humidity is low, especially, electrostatic adsorption is more likely to happen. This not only
shortens the service life of your device but also causes communications failures.
Table 2-1 lists the limit on dust content in the equipment room.
Table 2-1 Dust concentration limit in the equipment room
Substance
Dust particles
Note: Dust particle diameter ≥ 5 µm
In addition, the equipment room should meet the rigorous limits on salts, acids and sulfides to eliminate
corrosion and premature aging of some parts. Table 2-2 lists the limits on harmful gases in the
equipment room.
Concentration limit (particles/m
4
≤ 3 x 10 (No visible dust on desk in three days)
2-2
3
)