Rittal SK 3126.230 Assembly And Operating Instructions Manual - 4 Assembly and Connection
4 Assembly and connection
RITTAL Compact split cooling unit assembly and operating instructions
29
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
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
and -3-11 are adhered to, provided the supply im-
pedance is less than approx. 1.5
Ω.
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
RITTAL recommends connecting a conductor with a
nominal cross-section of at least 6 mm
2
to the poten-
tial equalisation connection point in cooling units,
and incorporating it into the existing potential equal-
isation system.
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 Installing the power supply
• Complete the electric installation using the electri-
cal circuit diagram shown on the rear of the exter-
nal unit and on the interior side of the maintenance
cover of the internal unit (see Fig. 1 on page 25,
legend on page 30).
• If you would like the system messages from the
cooling unit to be evaluated via the system mes-
sage relay, you should also connect a suitable
low-voltage cable to connection clamps 3 – 5.
Fig. 5:
Electrical wiring plan no. 1
22
21
X1
L1 L2 L3
1 2 3 4 5
PE
3
8
2
B1
B5
B2
2
2
S1
Mains
1
2
3
4 3 2 1
1 3 5
2 4 6
95
2
2
4
96
4 3 2 1
1 2 3
1 2 3
1 2
1 2
3
4
K1
K2
D1 – 2
D0 – A
MS1
Serial
Level GRE
NTC_I RED
NTC_E BLUE
A1
M1
F3 2
M2
M4 D1 – 5
Term
D1 – 3 D1 – 1 D1 – 4
PE
PE
5
Power
X2 X3
M2.1
M1
F2
F3.1
U
4
PE
PE
PE
PE
W
V
F4.1
M2.2
M4.1
M4.2
M4.3
A2
A2
3~
M
F5.1
3~
M
F5.2
3~
M
F5.3
3~
M
M4.4
F5.4
3~
M
U
V W PE
U
VW PE
U
VW PE
U
V WPE
U
V WPE
U
V W PE
F4.2
2
4
2
4
3~
M
B4
B3
1 2
2 4 1
3
NTC_A YEL
NTC_C WHI
X10
L1
X20
1 2 3 4 5 6 7 8 9 10
X20
1 2 3 4 5 6 7 8 9 10
L2 L3
L1 L2 L3
PE
X10
L1L2 L3
L1 L2 L3
PE
Evaporator coil
Condenser