Reference Guide

Table 14. Operating temperature de-rating specifications
Operating temperature de-rating Specifications
Up to 35°C (95°F) Maximum temperature is reduced by 1°C/300 m (1°F/547 ft) above
950 m (3,117 ft).
35°C to 40°C (95°F to 104°F) Maximum temperature is reduced by 1°C/175 m (1°F/319 ft) above
950 m (3,117 ft).
40°C to 45°C (104°F to 113°F) Maximum temperature is reduced by 1°C/125 m (1°F/228 ft) above
950 m (3,117 ft).
Standard operating temperature
Table 15. Standard operating temperature specifications
Standard operating temperature Specifications
Continuous operation (for altitude less than 950 m or
3117 ft)
10°C to 35°C (50°F to 95°F) with no direct sunlight on the
equipment.
Humidity percentage range 10% to 80% Relative Humidity with 29°C (84.2°F) maximum dew
point.
Expanded operating temperature
Table 16. Expanded operating temperature specifications
Expanded operating temperature Specifications
Continuous operation 5°C to 40°C at 5% to 85% RH with 29°C dew point.
NOTE: Outside the standard operating temperature (10°C to
35°C), the system can operate continuously in temperatures as low
as 5°C and as high as 40°C.
For temperatures between 35°C to 40°C, de-rate maximum allowable
temperature by 1°C per 175 m above 950 m (1°F per 319 ft).
≤ 1% of annual operating hours –5°C to 45°C at 5% to 90% RH with 29°C dew point.
NOTE: Outside the standard operating temperature (10°C to
35°C), the system can operate down to –5°C or up to 45°C for a
maximum of 1% of its annual operating hours.
For temperatures between 40°C and 45°C, de-rate maximum
allowable temperature by 1°C per 125 m above 950 m (1°F per 228 ft).
NOTE: When operating in the expanded temperature range, system performance may be impacted.
NOTE: When operating in the expanded temperature range, ambient temperature warnings may be reported in the System
Event Log.
Expanded operating temperature restrictions
● Do not perform a cold startup below 5°C.
● The operating temperature specified is for a maximum altitude of 3050 m (10,000 ft).
● 150 W/8 core, 165 W/12 core and higher wattage processor [Thermal Design Power (TDP)>165 W] are not supported.
● Redundant power supply unit is required.
● Non-Dell qualified peripheral cards and/or peripheral cards greater than 25 W are not supported.
● NVMe drives are not supported.
● NVDIMMs are not supported.
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PowerEdge R940 technical specifications