3Com H3C S7503E-S CHASSIS Installation Manual

Contents

2-3Temperature/Humidity RequirementsTo ensure the normal operation and service life of a switch, a certain level of temperature and humidityshould be maintained in the equipment room. If the humidity in the equipment room is too high for a longtime, it will lead to bad insulation of the insulating material or even creepage. Sometimes, themechanical performance changes of material, the rustiness and corrosion of some metal parts are alsolikely to occur. If the relative humidity is too low, the captive screws may become loose due to theshrinkage of the insulation washers. Meanwhile, the electrostatic is likely to be produced in the dryenvironment, which will jeopardize the CMOS circuit of the switch. The higher the temperature, thegreater the damage it will do on the switch. High temperature for a long time will speed up the agingprocess of the insulation materials, greatly lower the reliability of the switch and therefore affect itsservice life seriously.Table 2-1 Temperature/humidity requirementsTemperature Relative humidityWorking condition Idle condition Working condition Idle condition0 0C to 45 0C (32 0F to113 0F)–40 0C to +700C (–40 0Fto +158 0F)10% to 95%,noncondensing5% to 95%,noncondensingCleanness RequirementsDust is a big harm for the normal operation of the switch. The indoor dust accumulated on the chassiscan cause electrostatic adsorption, resulting in the poor contact of the connector or metal contact point.This happens more frequently when the relative indoor humidity is low, which will not only shorten theservice life of the switch, but also cause communication failure.The required specifications on dust content and particle diameter in an equipment room are shown inTable 2-2.Table 2-2 Dust concentration limit in the equipment roomPhysical active substance Concentration limit (particles/m³)Dust particle ≤3 x 10 4 (No visible dust on desk over three days)Note: Dust particle diameter ≥ 5μmExcept the requirements on dust, rigorous requirements on ingredient of salts, acids and sulfides of airin an equipment room are also set. These harmful gases will speed up the metal corrosion and theaging processes of certain parts. The equipment room should be protected from the invasion of harmfulgases such as SO 2, H 2S, NO2, NH 3 and Cl2, the value limits of which are shown in the following table:Table 2-3 Limits on harmful gases in the equipment roomGas Maximum concentration (mg/m3)SO 2 0.2H 2S 0.06NH 3 0.05