Rittal SK 3302.100 Assembly And Operating Instructions Manual - 4 Assembly and Connection
4 Assembly and connection
Rittal cooling unit assembly and operating instructions
13
EN
4.5.4 Door limit switch
– Each door limit switch must only be assigned to
one cooling unit.
– Several door limit switches may be connected in
parallel and operated on one cooling unit.
– The minimum cross-section for the connection
cable is 0.3 mm
2
for a cable length of 2 m.
– The line resistance to the door limit switch must not
exceed a maximum of 50
:.
– The door limit switch only supports a floating
connection; no external voltages.
– The contact of the door limit switch must be closed
when the door is open.
The safety extra-low voltage for the door limit switch
is provided by the internal power pack: Current
approx. 30 mA DC.
• Connect the door limit switch to terminals 1 and 2
of the connector.
4.5.5 Notes on the flicker standard
The flicker limits specified in standard EN 61 000-3-3
or -3-11 are adhered to, provided the supply im-
pedance is less than approx. 1.5
:.
Where necessary, the unit operator should measure
the connected impedance or consult the responsible
power supply company. If there is no way of influenc-
ing the supply impedance and sensitive installed
components (e.g. BUS) are subjected to interfer-
ence, a line reactor or starting-current limiting device
should be connected upstream of the cooling unit to
restrict the startup current of the cooling unit.
4.5.6 Potential equalisation
If, for EMC reasons, the unit is to be integrated into
the existing potential equalisation system at the
customer, a conductor with a larger nominal cross-
section can be connected to the potential equalisa-
mounted cooling units.
According to the standard, the PE conductor in the
mains connection cable is not classified as an equi-
potential bonding conductor.
4.6 Carrying out the electrical installation
4.6.1 Bus connection
(only in conjunction with several units
with an e-Comfort controller)
When using several cooling units, the serial device
interface X2 can be used to connect up to ten cool-
ing units with the bus cable (Model No. SK 3124.100).
When interconnecting, please note the following:
– De-energise the cooling units to be connected.
– Ensure proper electrical insulation.
– Make sure the cables are not laid in parallel to
power lines.
– Make sure that the lines are short.
4.6.2 Connection X3 for serial interface
The interface card (Model No. SK 3124.200) may be
connected to X3. This is used to evaluate system
messages in a PLC, for remotely setting parameters
and monitoring, or for integration into the facility
management system.
4.6.3 Installing external transformers
For SK 3361.x40 only.
Fig. 19:
Installing external transformers (SK 3361.x40 only)
Note:
The electrical signals at the X2 interface are
of an extra-low voltage (not extra-low safety
voltages to EN 60 335-1).
Caution!
Regarding the last slave unit in the
group, do not, under any circumstances,
connect the remaining socket of the
Y cable SK 3124.100 into interface X3
of the cooling unit!
Attachment of the
unit’s rear panel
Mounted on 35 mm
support rail
DIN EN 50 022
Electrical connection
cooling unit
Connection at
the customer’s
230 V
tion connection point (attachment points) on wall-