Service manual

HP E8401A, E8403A Product Specifications 57Appendix A
• All other slots blocked. Airflow decreases as additional slots are
opened.
• Performance shown for Worst Slot (slot 2). Airflow is greater in all
other slots.
• Fans on Full Speed. Minimum airflow is approximately 50% with
fans on Variable Speed.
• Air Filter Kit not installed. Airflow is reduced approximately 10%
with clean air filters installed.
• Measurements taken at 1,500m altitude.
Cooling Mode (High or
Variable)
Switchable on the front panel. Controls both impeller and fan.
High Fan Speed Mode: Full Airflow all the time.
Variable Fan Speed Mode:
Fan Speed increments through 5 discrete speeds as a function of power
supply temperature and reference temperature. Reference
temperature (pins 11,12 of Diagnostic Connector) is measured on
the backplane and is a function of load and ambient temperature.
At full load: Low Speed up to approximately 30°C ambient.
High Speed above approximately 40°C ambient.
At no load: Low Speed up to approximately 40°C ambient.
High Speed above approximately 50°C ambient.
Assuming default limits:
At full load: Low Speed up to approximately 30°C
High Speed above approximately 40°C
At no load: Low Speed up to approximately 40°C
High Speed above approximately 50°C
18.0
12.0
6.0
24.0
5.0 10.0 15.0 20.0 25.0
Airflow Through Module (liters/sec)
0.0
Worst Slot
Pressure Drop
Across Module
(mm H
2
0)