12
Preventive maintenance
Introduction
Preventive maintenance has to be carried out to keep the heat exchanger fit to meet
specifications. The unit also needs preventive maintenance with specific intervals to
avoid breakdown or inefficient operation and to maximize the unit‟s lifetime.
It is important to notice that intervals between maintenance can vary depending on the
specific environment of the unit.
Parts which need preventive maintenance:
Heat exchanger
Fans
Caution
Switch off DC supply before working on the unit
Make sure that all work has been performed correctly before switching power back
on
Cleaning/-
inspection
The unit must be cleaned according to the recommended preventive maintenance in-
tervals of six months.
Remove front cover to access to the internal and the external fans. The core can be in-
ternally cleaned as well.
Trouble shooting
Operating errors may occur. Follow the columns from left to right to trouble shoot the
problem at hand.
Problem
Cause
Solution
The red LED illuminates
constantly
Too high temperature in
the enclosure, above
70 °C or fan failure
See if airways are free and
clean. See “Cleaning”
above.
Replace fan if necessary
The red LED is flashing
Onboard sensor has been
disconnected/shorted
See if test plug is in place.
Replace controller if nec-
essary
The internal fan runs at
low speed
Temperature in the enclo-
sure below 20 °C
This is due to the control
strategy
The external fan runs at
low speed
Temperature in the enclo-
sure below 30 °C
This is due to the control
strategy
