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42 Electrical design and installation
Manual Energy Storage Inverter ESI-S
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When the ESI-S consists of only one enclosure, the enclosure’s PE-point must be
connected directly to the installation’s PE-point
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When the ESI-S consists of more than one enclosure, each enclosure’s PE-point
must be connected directly to the installation’s PE-point. Additionally, all cubicles’
secondary PE-points must be interconnected. This is illustrated in
. The
interconnection cable should be minimum 16 mm².
Master
Slave 1
Slave 2
PE
PE
PE
Main earth
connection
point in
filter
cubicles
Secondary
earth
connection
point
Figure 29: Earth connection guidelines for a multi-unit ESI-S
6.6 Selection of the power cable size
Several types of power cable can be used to connect the inverter to the network. Local
regulations and habits often determine the user’s choice. Note however that due to the
high frequency output inverter of the ESI, there is no radiated emission through the
feeding cables. Consequently, there is no need for special screening of the inverter
connection cables.
The following steps have to be followed to determine the section of the power cables
feeding the inverter:
1. Determine the RMS current rating of the enclosure for which the cable has to be rated
(Irms).
The rating is marked on the enclosure label.
Each enclosure has to be individually connected to the supply and bottom cable entry
has to be used. If required an optional cable connection box can be added to allow for
multi-cable termination.
The minimum cable section to be used for the power conductors is 16 mm².
The RMS current for which the cable has to be rated equals the current rating of the unit
to be connected to the supply. Note that the neutral connection has to be able to carry
three times the unit current rating.
2. Determine the factor X and the cable section required taking into account the skin
effect.