D-EIMWC01008-16_03EN - 29/35
The power supply to the unit must be set up in such a way that it can be switched on or off independently from that of other
system components and other equipment in general, by means of a general switch.
The electrical connection of the panel must be carried out maintaining the correct sequence of the phases. Refer to the
specific wiring diagram for the unit you have bought. Should the wiring diagram not be on the unit or should it have been
lost, please contact your manufacturer representative, who will send you a copy. In case of discrepancy between wiring
diagram and electrical panel/cables, please contact the manufacturer representative.
Do not apply torque, tension or weight to the main switch terminals. Power line cables must be
supported by appropriate systems.
To avoid interference, all control wires must be connected separately from the power cables. To do this, use several
electrical passage ducts.
Simultaneous single and three-phase loads and phase unbalance can cause ground losses of up to 150 mA during normal
unit operation. If the unit includes devices that generate higher harmonics, such as an inverter or phase cut, ground losses
can increase to much higher values, about 2 A.
The protections for the power supply system must be designed according to the values mentioned above. A fuse must be
present on each phase and, where provided for by the national laws of the country of installation, a leak detector to earth.
This product complies with EMC (Electromagnetic Compatibility) standards for industrial environments. Therefore, it is not
intended for use in residential areas, e.g. installations where the product is connected to a low voltage public distribution
system. Should this product need to be connected to a low voltage public distribution system, specific additional measures
will have to be taken to avoid interference with other sensitive equipment.
Before any electrical connection work to the compressor motor and / or the fans, make sure that the
system is switched off and the main switch of the unit is open. Failure to observe this rule could
result in serious personal injury.
7.4
Cable requirements
The cables connected to the circuit breaker must respect the insulation distance in the air and the surface isolation distanc e
between the active conductors and the earth, according to IEC 61439-1 table 1 and 2, and to the local national laws.
The cables connected to the main switch must be tightened using a pair of keys and respecting the unified clamping values,
relative to the quality of the screws of the washers and nuts used.
Connect the earth conductor (yellow / green) to the PE ground terminal.
The equipotential protection conductor (earth conductor) must have a section according to table 1 of EN 60204 -1 Point
5.2, shown below.
Table 1 - Table 1 of EN60204-1 Point 5.2
Section of the
copper phase
conductors
feeding
the equipment
S
[mm
2
]
Minimum cross-
section of the
external copper
protection
conductor
S
p [mm
2
]
S
≤ 16
16 <
S
≤ 35
S
> 35
S
16
S
/2
In any case, the equipotential protection conductor (earth conductor) must have a cross section of at least 10 mm
2
, in
accordance with point 8.2.8 of the same standard.
7.5
Phase unbalance
In a three-phase system, the excessive imbalance between the phases is the cause of the engine overheating. The
maximum permitted voltage unbalance is 3%, calculated as follows:
𝑈𝑛𝑏𝑎𝑙𝑎𝑛𝑐𝑒 % =
(𝑉𝑥 − 𝑉𝑚) ∗ 100
𝑉𝑚
where:
V
x
= phase with greater unbalance
V
m
= average of the tensions
