ICAR by ORTEA NEXT
MAT189 jun19
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6.5
E
LECTRICAL CONNECTION
DANGER T
HE ELECTRICAL CONNECTION MUST BE CARRIED OUT BY TRAINED AND QUALIFIED PERSONNEL
,
AWARE OF THE
INVOLVED RISKS
. A
LWAYS USE SUITABLE TOOLS AND
P
ERSONAL
P
ROTECTIVE
E
QUIPMENT
(PPE). T
HE OPERATIONS MUST
BE CARRIED OUT IN CONFORMITY WITH THE RULES AND REGULATIONS ENFORCED IN THE
C
OUNTRY OF INSTALLATION
.
Note
The cross-section value of the cables/bars for the connection to mains and load falls entirely under
the installer’s responsibility. The Manufacturer shall not be held liable for any damage that might occur to
people or belongings due to an incorrect choice.
Open the cubicle and locate the connection terminals. Prepare the connection cables/bars with regard to the
current values and make them go through the openings prepared on purpose trying to avoid kinks and
accidental contact between the cables and the electric components.
6.5.1
Ground connection
The very first operation is to connect the earth wire to the terminal identified by PE, GRD or the symbol
G
.
DANGER T
HE EARTH CONDUCTOR MUST NEVER BE ELECTRICALLY INTERRUPTED NEITHER INSIDE NOR OUTSIDE THE UNIT
.
The earth wire cross-section must be chosen in conformity to the regulations in force. Therefore, depending
on the phase cable cross-section, the earth wire cross-section should respect the values in the table below:
P
HASE CABLE CROSS
-
SECTION
S [sqmm]
E
ARTH WIRE MIN CROSS
-
SECTION
[sqmm]
S ≤ 16
S
16 < S ≤ 35
16
35 < S ≤ 400
S/2
400 < S ≤ 800
200
S > 800
S/4
Note
If a not standardised cross-section is determined, the nearest larger one should be chosen.
6.5.2
Connection to main power supply
The three phases of the mains should be connected, via adequately sized power cables (refer to annex E), to
the terminals of the load disconnect switch marked by the letters L1, L2 and L3 (R, S and T) respectively.
The table below shows the load break switch terminal distance from the base of the equipment (*)
LOAD
-
BREAK SWITCH SIZE
[
A
]
250
400
630
800
1250
CABINET HEIGHT [mm]
DISTANCE
[mm]
1760
455
405
395
380
367
1960
353
342
325
320
2160
303
290
280
268
2360
265
255
240
(*) Distances apply only to the MULTImatic cabinets in the catalogue.
6.5.3 Current Transformer (CT) connection
Connect terminals S1 and S2 (S11 and S12 in MIDImatic and MULTImatic units) to the secondary of a current
transformer (not supplied) with 5A secondary current connected on phase L1 (R) (see Annex B). In order to
ensure the correct operation of the automatic control it is essential for the unit to be connected as described
in the above mentioned annex, which also illustrates some typical connection mistakes.
Being the current transformer a measuring instrument and not merely a display instrument, it should
possess certain characteristics, besides being of high quality:
CT Apparent power
The Apparent Power of the current transformer (expressed in VA) should be such as to meet the self-
consumption of both the controller current input and the connecting cable (see table below).
CABLE SIZE
[mm
2
]
VA
PER METER OF CABLE AT
20°C
2,5
0,41
4
0,254
6
0,169
10
0,0975
16
0,062
For each 10°C variation in temperature, the VA absorbed by the cables increase by 4%; the values given
above are deduced from typical resistances of flexible cables, class 5
Minimum size of connection of cables between current transformer and controller.
CT amperage
The primary amperage of the current transformer should be determined by the user solely in relation to the
current drawn by the load that needs to be corrected.
CT position