General Maintenance Operations; Special Maintenance Operations; Operations To Be Carried Out By Qualified Personnel Or By The Manufacturer; Troubleshooting Guide - Carrier DB-S Series Use & Maintenance Instructions

GB
D
F
9.1 General maintenance
I
operations

9.2 Special maintenance operations

9.3 Operations to be carried out
by qualified personnel or by
the Manufacturer

9.4 Troubleshooting guide

18
9 9 . . M M A A I I N N T T E E N N A A N N C C E E A A N N D D R R E E P P A A I I R R S S
9 9 . . M M A A I I N N T T E E N N A A N N C C E E A A N N D D R R E E P P A A I I R R S S
A
dequate maintenance is an important factor to ensure the long life and optimum
performance of the unit and the safety conditions required by the Manufacturer.
It is essential to clean the condenser which is located in the lower part of the
compressor unit (externally to the cell) in an easily accessible position.
The condenser is used to cool the refrigerating gas and it will work more effecti-
vely if it is kept free of dust.
The unit can be cleaned by simply using a dry brush and reaching deep between
the condenser's fins or, better still, by using an air jet and blowing from the inside
out. This operation must be carried out while the unit is switched off.
If there are traces of oil on the condenser, check where they come from and,
having repaired the leak, clean using a detergent such as alcohol or petrol.
WARNING: To avoid cutting your hands, use protective gloves.
Periodically check the wear of electrical contacts and remote control switches and
replace if necessary.
Below is a list of maintenance operations that require specific technical compe-
tencies and must therefore be carried out by qualified personnel or by the
Manufacturer.
The User must on no account:
- replace electrical components
- tamper with the electric system
- make repairs on mechanical parts
- tamper with the refrigerating system
- tamper with the control panel
- tamper with safety and protection devices
Technical problems that may occur during the operation of the machine:
1. In case of malfunction of the system, check the refrigerating gas through the flow
indicator located on all units fitted with a thermostat (this must be checked when the
unit is operating and the cell temperature is close to the required temperature).
Normally the indicator is clear, while, in the absence of gas, gas bubbles will appear.
2. If the compressor or fan stop, check the following:
- whether the safety fuses of the main and auxiliary circuit have been blown, in
which case they should be replaced, after checking the suitability of the mains
tension and ensuring that phase polarity is correct.
- if the compressor unit has stopped working (the indicator light on the panel is
on) it is necessary to reset the thermal relay manually, having first identified the
causes of the malfunction.
3. In case of unit malfunction check the following:
- that the evaporator is not frosted over. If it is, immediately defrost the evaporator
completely, by adjusting the timer (located inside the electric control panel) and star-
ting the defrosting cycle manually. Once the defrosting cycle is completed, check if
any ice is left on the evaporator, then repeat the operation described above. Shorter
time intervals between defrosting cycles should be set to reduce ice formation.
CAUTION:
On no account should sharp or pointed metal instruments, or hot water be used
to remove any blocks of ice that might have formed in the evaporator.