Mitsubishi Electric 700 Series Instruction Manual page 23

Installation of the inverter and enclosure design
(3) Arrangement of multiple inverters
When multiple inverters are placed in the same
enclosure, generally arrange them horizontally as shown
in the right figure (a). When it is inevitable to arrange
them vertically to minimize space, take such measures as
to provide guides since heat from the bottom inverters
can increase the temperatures in the top inverters,
causing inverter failures.
When mounting multiple inverters, fully take caution not
to make the surrounding air temperature of the inverter
higher than the permissible value by providing ventilation
and increasing the panel size.
(4) Arrangement of ventilation fan and inverter
Heat generated in the inverter is blown up from the bottom of
the unit as warm air by the cooling fan. When installing a
ventilation fan for that heat, determine the place of ventilation
fan installation after fully considering an air flow. (Air passes
through areas of low resistance. Make an airway and airflow
plates to expose the inverter to cool air.)
12
Inverter Inverter
Enclosure
(a) Horizontal arrangement
Arrangement of multiple inverters
Inverter
<Good example>
Placement of ventilation fan and inverter
Inverter Inverter
Guide Guide
Guide
Inverter Inverter
Enclosure
(b) Vertical arrangement
Inverter
<Bad example>