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. 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.
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
an internal enclosure temperature of
35°C. This means that the performance 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.
L
Checking the enclosure temperature.
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.
Checking the control behaviour of
cooling devices
Another easy way of checking an enclosure
climate control system is to observe the
Climate control
from the smallest
to the largest.
ENCLOSURES
POWER DISTRIBUTION
CLIMATE CONTROL