Safety Equipment; Condensation; Door Limit Switch; Additional Interface X3 - Rittal CS 9761.212 Montageanleitung Und Bedienungsanleitung

3 Unit description

3.1.4 Safety equipment

– In the cooling cycle, the cooling unit has a tested
EN
pressure-operated switch to EN 12 263 which is
set to maximum PS (admissible pressure); this
operates via an automatic reset device whenever
the pressure drops again.
– Temperature monitoring prevents the evaporator
coil from icing over. If there is a risk of icing, the
compressor switches itself off and automatically
switches itself back on again at higher tempera-
tures.
– The refrigerant compressor and the fans are
equipped with thermal winding shields to protect
against excess current and excess temperatures.
– In order to allow a reduction of pressure inside the
compressor and hence a safe restart, once it has
been switched off (e.g. upon reaching the set tem-
perature via the door limit switch function or via
de-energising), the device will switch back on with
a delay of 180 seconds.
– The device has one integral floating contact on the
connection clamp (system message relay with
changeover contact, terminal 3 – 5) which may be
used to retrieve messages from the cooling unit,
e.g. via PLC.

3.1.5 Condensation

The outdoor cooling unit has a protection category of
IP 55 to EN 60 529. The protection category refers to
the sealing of the inner circuit from the outer circuit.
When used with twin-walled CS outdoor enclosures
in the CS Toptec or CS modular enclosure series, the
protection category IP 55 of the basic enclosure is
preserved, provided it is installed correctly.
Condensation inside the enclosure is more or less
excluded, thanks to the hermetically sealed air cir-
cuit.
There is only a risk of condensation inside the enclo-
sure in the following situations:
– During maintenance work on the open enclosure in
warm air with a high level of humidity.
– During maintenance work on the open enclosure in
rain.
– If the cooling unit is operated with the door open.
Deactivation of the cooling unit when the door is
open can be achieved by installing a door limit
switch (e.g. PS 4127.010) (see "3.1.6 Door limit
switch").
26

3.1.6 Door limit switch

The cooling unit may be operated with a floating door
limit switch connected. The door limit switch is avail-
able as an accessory (Model No. PS 4127.010).
The door limit switch function causes the fans and
the compressor in the cooling unit to be switched off
after approximately 15 seconds when the enclosure
door is opened (contacts 1 and 2 closed). This pre-
vents the formation of condensation inside the enclo-
sure while the enclosure door is open. In order to
prevent damage to the unit, it is equipped with an
ON delay: The evaporator fan cuts back in with a
delay of approximately 15 seconds after the door
has been closed, while the condenser fan and com-
pressor switch on after approximately 3 minutes.

3.1.7 Additional interface X3

Note:
The electrical signals at the interface are of
an extra-low voltage (not extra-low safety
voltages in accordance with EN 60 335).
An additional interface card may be connected to
the 9-pole SUB-D connector X3 in order to incorpo-
rate the cooling unit into superordinate monitoring
systems (available as an accessory, interface card
Model No. SK 3124.200).

3.2 Proper use

RITTAL outdoor cooling units were developed and
designed in accordance with the state-of-the-art and
the recognised rules governing technical safety.
Nevertheless, if used improperly, they may pose a
threat to life and limb or cause damage to property.
The unit is only intended for cooling and heating of
outdoor enclosures.
Any other use is deemed improper. The manufac-
turer will not be liable for any damages caused as
a result of improper use, or for incorrect assembly,
installation or use. All risk is borne solely by the user.
Proper usage also includes the observation of all
valid documents and compliance with the inspection
and servicing conditions.
RITTAL outdoor cooling unit assembly and operating instructions