Mitel Aastra 470 System Manual page 39

Fig. 6 Aastra 470 basic system
For electrical and thermal reasons the dummy covers must always be fitted. They
are removed only to expand the basic system with interface cards or an application
card.
For a clearer overview the figure below shows the open communications server
from above with an additional fan fitted. The housing cover is in two parts. The up-
per, rear cover must be removed for the purpose of fitting an additional fan (see
"Fitting an additional fan", page 95
Standard fan (fitted)
Redundant fan
unit as an option
(RFU)
Call Manager card
(CPU1)
Fig. 7 Aastra 470 basic system fitted with a redundant fan unit
Aastra 470 as of R3.2
syd-0337/1.6 – R3.2 – 09.2014
Expansion Stages and System Capacity
for the procedure).
Internal power supply
unit (PSU2U)
Backplane (BP2U)
Plug-in connections
for the interface
cards
39