Publicité
4 Assembly and connection
4.5 Notes on electrical installation
GB
When carrying out the electrical installation, it is
important to observe all valid national and regional
regulations as well as the provisions of the respon-
sible power supply company. Electrical installation
must only be carried out by a qualified electrician
who is responsible for compliance with the existing
standards and regulations.
4.5.1 Connection data
– The connection voltage and frequency must match
the values specified on the rating plate.
– The cooling unit must be connected to the mains
via an all-pin isolating device, which ensures at
least 3 mm contact opening when switched off.
– No additional temperature control must be con-
nected upstream of the device at the supply end.
– Install the pre-fuse cited on the rating plate (minia-
ture circuit-breaker "K" characteristic or slow fuse)
to protect the cable and equipment from short-
circuits.
– The mains connection must ensure noiseless
potential equalisation.
4.5.2 Overvoltage protection and
supply line load
– The unit does not have its own overvoltage protec-
tion. Measures must be taken by the operator at
the supply end to ensure effective lightning and
overvoltage protection. The mains voltage must
not exceed a tolerance of ±10 %.
– In accordance with IEC 61 000-3-11, the unit is
intended solely for use at sites with a continuous
current-carrying capacity (incoming mains power
supply) of more than 100 A per phase and with a
supply voltage of 400/230 V. If necessary, the
power supply company must be consulted to
ensure that the continuous current-carrying capac-
ity at the point of connection to the public grid is
sufficient for connection of such a unit.
– The fans and compressors in single- and three-
phase units are intrinsically safe (thermal winding
protection). This also applies to the transformer
versions of types SK 3304.110, SK 3304.510,
SK 3305.110, SK 3305.510, SK 3328.110,
SK 3328.510, SK 3329.110 and SK 3329.510 and
to special-voltage units which are likewise
equipped with a transformer.
12
– Install the pre-fuse cited on the rating plate (minia-
ture circuit-breaker with "K" characteristic, motor
circuit-breaker or transformer circuit-breaker) to
protect the cable and equipment from short-cir-
cuits. Select the motor circuit-breaker/transformer
circuit-breaker in accordance with the information
supplied on the rating plate: Set it to the minimum
value specified. This will achieve the best short-
circuit protection for cables and equipment.
Example: Specified setting range MS/TS
6.3 – 10 A; set to 6.3 A.
4.5.3 Three-phase devices
– The three-phase variant of models SK 3304.xxx,
SK 3305.xxx, SK 3328.xxx, SK 3329.xxx and
SK 3332.xxx must be connected to a TN grid with
earthed star point (current setting as per rating
plate). Special-voltage three-phase units must
be protected with a transformer circuit-breaker
(category AC-3) as per the rating plate.
– Units designed for three phase 400/460 V have
additional monitoring of the rotary field or the
absence of a phase. If the rotary field is incorrect
or a phase is absent, the unit will not run.
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
2
cable is 0.3 mm
for a cable length of 2 m.
– The line resistance to the door limit switch must not
exceed a maximum of 50 Ω.
– The door limit switch only supports a floating con-
nection; 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 impedance is less than approx. 1.5 Ω .
Where necessary, the unit operator should measure
his connected impedance or consult the responsible
power supply company. If there is no way of influ-
encing the supply impedance and sensitive installed
components (e.g. BUS) experience interference, 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.
Rittal cooling unit assembly instructions
Publicité
