Rockwell Automation Publication ICSTT-RM448J-EN-P - April 2018
79
Before You Begin
Chapter 4
System Design
Considerations for Heat
Dissipation and Cooling
The controller is designed to operate in its specified environment without
forced air cooling. However, forced air cooling may be needed in individual
circumstances when the controller shares its enclosure with other heat
producing equipment and the internal temperature could exceed the
recommended operating temperature range.
Module Orientation
Rockwell only recommend that modules are oriented vertically, if modules are
mounted in any other orientation then specific temperature tests must be done
to ensure reliable and predictable operation.
Maximum Air Temperature
The maximum air temperature rating in an enclosure where AADvance
modules are installed to ensure predictable operation is 70 °C (158 ° F).
Estimate Heat Dissipation
The heat in the enclosure is generated from several sources such as the power
supplies, the AADvance modules and some of the field loop power. Use the
following calculation and the data given in the tables to estimate the overall
heat dissipation:
• Power supply consumption (Watts x (100-efficiency) (%) + the sum of
the system power consumed by the m part of the field power
that is in the enclosure.
Table 7 - Module Supply Power Heat Dissipation
The following module power dissipation values are worst case values over the
range of operating voltages and currents.
Item
Number of
Modules
Module Power
Heat Dissipation
Subtotal
(W/BTU/hr)
T9110 Processor Module
× 8.0 W (27.3 BTU/hr.)
=
T9401 Digital Input Module 24 Vdc, 8 channel
× 3.3 W (11.3 BTU/hr.)
=
T9402 Digital Input Module 24 Vdc, 16 channel
× 4.0 W (13.6 BTU/hr.)
=
T9431 Analogue Input Module, 8 channel
× 3.3 W (11.3 BTU/hr.)
=
T9432 Analogue Input Module, 16 channel
× 4.0 W (13.6 BTU/hr.)
=
T9451 Digital Output Module, 24 Vdc, 8 channel
× 3.0 W (10.2 BTU/hr.)
=
T9482 Analogue Output Module, 8 channel, isolated
× 3.6 W (12.3 BTU/hr.)
=
Total:
