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Hardware Installation Guide for the Cisco 4000 Series  Integrated Services Router
OL-32185-02
Chapter 2      Cisco 4000 Series ISRs Preinstallation
  General Site Requirements
• Do not modify power cables or plugs. Consult a licensed electrician or your power company for site 
modifications. Always follow your local and national wiring rules.
• If you turn off your system, wait at least 30 seconds before turning it on again to avoid system 
component damage.
Site Selection Guidelines
Cisco 4000 Series ISRs require specific environmental operating conditions. Temperature, humidity, 
altitude, and vibration can affect the performance and reliability of the router. The following sections 
provide specific information to help you plan for the proper operating environment.
Cisco 4000 Series ISRs are designed to meet the industry EMC, safety, and environmental standards 
described in the Regulatory Compliance and Safety Information for the Cisco 4000 Series ISRs 
document.
Site Environmental Requirements
Environmental monitoring in the router protects the system and components from damage caused by 
excessive voltage and temperature conditions. To ensure normal operation and avoid unnecessary 
maintenance, plan and prepare your site configuration before installation. After installation, make sure 
the site maintains the environmental characteristics as shown in Table 2-1.
Table 2-1 Router Environmental Tolerances
Environmental Characteristic Minimum Maximum
Steady State Operating 0 degree C 40 degree C
(40 degrees C at 10,000 
feet)
Storage  –20 degrees C +70 degrees C
Humidity operating (noncondensing) 10% 90%
Humidity nonoperating (noncondensing) 5% 95%
Altitude operating: over allowable temperature 
range (0 to 50 degrees C)
–500 feet  10,000 feet
Altitude, nonoperating: over allowable temperature 
range
–1000 feet 50,000 feet
Thermal shock non-operating with change over time 
of 3 minute
–25 degrees C +70 degrees C
Thermal Shock - Operating at 2.5 degree C per 
minute
0 degrees C +50 degrees C