How to check
if Cooling Output
inside Enclosures
is Sufficient
By Jason Swann, Rittal Product Manager for Climate
Manufacturing automation systems are delicate and very expensive pieces of kit, which perform vital
functions for the businesses they serve. The enclosures that protect them must have strictly controlled
internal environments with interior temperatures that are carefully maintained within a few degrees.
If not, the impact can be harmful to the inverter drives, power supplies, contactors, PLCs and other
electrical and electronic components operating within them. This requires careful control of the
climate within the enclosure. Here, we offer some practical tips on how to evaluate an existing
enclosure climate control through a series of simple checks.
ike all electrical equipment,
drives create heat and
they therefore have a
major influence on the
temperatures inside
enclosures. Drives are often quoted as
having efficiency of 97 per cent, so one
with a rated output of 150kW can produce
as much as 4.5kW of heat.
L
an internal enclosure temperature of
35°C. This means that the performance
of a cooling unit should be specified
so that the average internal enclosure
temperature of 35°C can be guaranteed
under all load conditions and under all the
ambient conditions that could be met at
the machine’s location.
Checking the enclosure temperature.
As well as the heat loss inside the
enclosure, ambient temperatures within
a production facility will also have an
impact on the temperatures that a drive
is operating within. A typical enclosure
climate control system is designed for
The first check is to measure the
temperature within the enclosure to assess
its climate control capability. Temperature
sensors should be placed in a position
within the airflow of the enclosure,
sensors should not be placed on or near
direct airflow from high temperature
components. Otherwise temperature
readings can be found to be inaccurate.
The sensors should be left to monitor the
temperature trend over a period of time.
If the sensor records air temperatures
of well over 35°C (set point) then the
output of the cooling unit should either
be considered insufficient or, alternatively,
that there has been a malfunction of the
cold air routing in the enclosure. This
means that the cooling air cannot reach (or
can only partially reach) the temperature-
sensitive components.
Enclosures
from the smallest
to the largest.
ENCLOSURES
POWER DISTRIBUTION
CLIMATE CONTROL