Nevion DWDM-40C - Manual (Page 11)

DWDM-40C Rev. A
nevion.com | 11
current is proportional to the temperature difference between the ambient temperature and
the desired temperature within the laser package.
If the ambient temperature is lower than the package temperature, the power dissipated will
support the heating process of the device by increasing the ambient temperature. On the
other hand, if the ambient temperature is much higher than the desired package temperature
(about +22°C) it may cause the laser to malfunction. The current, which is proportional to the
temperature difference, implies power dissipation and an increase of the ambient
temperature.
This increased ambient temperature will again increase the current through the Peltier
element in order to lower the internal package temperature. The increased current will make
more power dissipate thereby increasing the ambient temperature, and so on.
To avoid this, proper ventilation of the DWDM-system is needed. A 40-channel system needs
12RU-26ru of rack space. Additional rack space needed for ventilation is 1RU above and
below each set of 4 flashlink frames (8RU). Receiver cards generate less heat than
transmitter cards, and bidirectional cards decrease the number of cards in a 40-channel
system. Please consult with Network Electronics before building a 40-channel system.
Example with 6 flashlink frames, frame space utilisation depending on card types:
1RU
Fan, hot air exhaust
6RU 3x flashlink DWDM frames
1RU Cold air intake
2RU flashlink DWDM filter frame
1RU Fan, hot air exhaust
6RU 3x flashlink DWDM frames
1RU Cold air intake
The operational temperature for the DWDM-system is 0°-40°C.