Unit Description; Functional Description; How It Works; Control - Rittal CS 9761.212 Montageanleitung Und Bedienungsanleitung

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Unit description

3.1 Functional description

Enclosure cooling units are designed to dissipate
heat from enclosures by cooling the air inside the
enclosure and so protect the temperature-sensitive
components.
Cooling units that are suitable for outdoor use can be
used for outdoor applications on a permanent basis
owing to the top-quality material they are made of
and because of the high IP protection they provide.
They are appropriate for ambient temperatures from
–33°C to +55°C (in the shade).
Outdoor cooling units are particularly appropriate for
the temperature range of +35°C to +55°C, where
similar systems such as air/air heat exchangers or
systems with filtered ambient air cannot be used for
technical reasons to effectively and economically
dissipate heat loss.
The cooling unit has an integral heater. The function
of this heater is to increase the internal temperature
to prevent condensation in case of a low ambient
temperature. If the heating capacity is insufficient,
we recommend using a separate additional heater
controlled via a thermostat, such as the 800 W heater
SK 3105.200 and thermostat SK 3110.000.
Heating output of the integral heater:
• 400 W: CS 9761.212, CS 9762.212
• 800 W: CS 9768.152
Outdoor cooling units from RITTAL are specifically
tailored to the twin-walled outdoor enclosure sys-
tems CS Toptec and CS modular enclosures.
Adapting these cooling units with enclosures
other than the ones supplied by RITTAL and the
use of single-walled outdoor enclosures is only
possible after consultation.

3.1.1 How it works

The cooling unit (compression refrigeration system)
is comprised of four main components (cf. Fig.1): the
evaporator (1), the coolant compressor (2), the con-
denser (3), and the control or expansion valve (4),
which are connected by suitable pipework.
This circuit is filled with a readily boiling substance,
the refrigerant. Coolant R134a (CH
free. Its Ozone Depletion Potential (ODP) is 0, mak-
ing it very eco-friendly. A filter dryer (5) which is inte-
grated into the hermetically sealed cooling circuit
provides effective protection against moisture, acid,
dirt particles, and foreign bodies within the cooling
circuit.
RITTAL outdoor cooling unit assembly and operating instructions
In the evaporator coil (1), the liquid coolant is con-
verted to a gaseous state. The energy needed for
this purpose is taken from the enclosure air in the
form of heat, which has the effect of cooling the en-
closure air. In the compressor (2), the coolant is
heavily compressed, so that it achieves a higher
temperature inside the condenser (3) than the ambi-
ent air. This means that excess heat may be emitted
to the ambient air via the surface of the condenser,
as a result of which the temperature of the coolant
drops and it is converted back into liquid. It is re-
injected into the evaporator coil via a thermostatic
expansion valve (4), which causes it to cool down
further, and is then once again able to absorb the
energy from the enclosure air in the evaporator coil.
The whole cycle begins again.
pressure-
operated
Compressor
External circuit
Internal circuit
Evaporator coil (1)
Fig. 1:

3.1.2 Control

RITTAL outdoor cooling units are equipped with
a Comfort controller, via which the functions of the
cooling unit may be set (for display reading and
extended functions, please refer to chapter
"6 Operation", page 32).

3.1.3 Bus mode (Comfort controller only)

The serial unit interface X2 allows you to create a
bus connection with up to ten cooling units using
the master-slave cable (shielded, four-wire cable,
Model No. SK 3124.100).
This allows you to implement the following functions:
– Parallel unit control (the cooling units in the network
can be switched on and off simultaneously)
FCF ) is chlorine- – Parallel door status message ("door open")
2 3
– Parallel collective fault message
Data is exchanged via the master-slave connection.
During commissioning, assign an address to each
unit that also includes the identifier "master" or
"slave".
3 Unit description
H
PSA
switch
Condenser fan
(2)
Evaporator fan
Cooling circuit
EN
Condenser (3)
Filter dryer (5)
Temperature
control
Expansion valve (4)
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