10
Fig. 9.3
Condensate discharge
10. Handling Instructions
Storage, maintenance, transport and disposal
As a maintenance-free, hermetically sealed
system, the cooling circuit has been filled in the
factory with the required amount of refrigerant,
and tested for leaks and subjected to a function
trial run.
The installed maintenance-free fans use ball
bearings, they are protected against moisture and
dust, and are fitted with a temperature monitor.
The life expectancy is at least 30,000 operating
hours. The cooling unit is thus largely mainte-
nance free. All that may be required from time to
time is that the components of the external air
circuit are cleaned by compressed air. The use of
a filter mat is recommended only if large particles
of lint are present in the air, so that blockage of the
condenser is prevented. (Filter mat replacement,
fig. 7.1). Note: Prior to any maintenance work, the
power to the cooling unit must be disconnected.
Storage temperature: The cooling units must not
be exposed to temperatures above +70°C.
Transport position: The cooling units must always
be transported upright.
Waste disposal: The closed cooling circuit
contains refrigerant and oil which must be
correctly disposed of for the protection of the
environment. Disposal can be carried out at
Rittal.
We reserve the right to make technical
modifications.
11. Scope of supply and
guarantee
1 cooling unit, ready for connection
1 drilling template
1 sealing plate
1 sealing frame
1 set of mounting and operating instructions
1 plug-in terminal strip
Guarantee:
This unit is covered by a 1-year guarantee from the
date of supply, subject to correct usage (see also
Safety notices under heading 4.). Within this period,
the returned unit will be repaired in the factory or
replaced free of charge. The cooling unit is to be
used for the cooling of enclosures only. If it is con-
nected or handled improperly the manufacturer’s
guarantee does not apply and in this case we are
not liable for any damage caused.
1
/
2
′′
9. Technical information
The cooling unit (compressor refrigeration unit)
consists of four main components: the coolant
compressor, evaporator, condenser, and the
control or expansion valve, which are connected
by suitable pipework. This circuit is filled with
a readily boiling substance, the refrigerant. The
R134a (CH
2
FCF
3
) refrigerant is free from chlo-
rine. It has an ozone destroying potential (ODP)
of 0 and is therefore environmentally friendly. A
filter dryer which is integrated in the hermetically
sealed cooling circuit, provides effective protec-
tion against moisture, acid, dirt particles, and
foreign bodies within the cooling circuit.
9.1 Operation of the cooling unit
Fig. 9.1
Operation of the cooling unit
The compressor takes the gaseous refrigerant
from the evaporator and compresses it to a
higher pressure in the condenser. During this
process the temperature of the refrigerant rises
above the ambient temperature and heat can be
dissipated to the environment via the surface of
the condenser. Then the refrigerant is liquefied
and, by means of a thermostatically controlled
expansion valve, returned to the evaporator,
where it evaporates at low pressure. The heat
required for complete evaporation is drawn from
the enclosure interior causing it to cool down.
The cooling cycle is thus completed, the afore-
mentioned process of the heat transfer starts
afresh.
9.2 Safety equipment
The cooling circuit of the cooling unit has a
component-tested, high-pressure monitor to
EN 12 263, which is set to maximum PS (allowed
pressure) and operates via an automatic reset
device in case of recurring pressure drop. Tem-
perature monitoring will prevent the evaporator
from icing up. If there is a risk of icing up, the
compressor is switched off and automatically
switched on again at higher temperatures.
The refrigerant compressor and the fans are
equipped with thermal winding protection
switches against excess current and excess
temperatures.
9.3 Condensate discharge
A cast gutter in the evaporator tray ensures that
any condesate which may form on the evapora-
tor (at high air humidity, low temperatures inside
the enclosure), is drained away to the right or
rear of the unit. For this purpose, a length of
hose should be fitted to one of the two conden-
sate pipe connection pieces (see fig. 9.3). The
other drain that is not used has to be sealed
accordingly. The condensate must be able to
run off freely. If the condensate is to be drained
off over a greater distance, then care must be
taken that the hose is free from kinks and a
check for correct drainage made. Units with a
comfort controller have an additional conden-
sate alarm.
Fan 2
Fan 1
Compressor
Evaporator
External circuit
Internal circuit
Expansion valve
Thermostat
Filter
dryer
Liquefier
PSA
monitor
H
English
03_SK3382_8_11_eng.fm Seite 10 Freitag, 5. März 2004 4:33 16
