ZGR SOLAR STR 250
Operation manual
www.zigor.com
22
The external connections available in the
ZGR SOLAR STR 250
are (Table 4-8 and Table 4-9):
No CABLE
TYPE
SPECIFICATION
CABLE DIAMETER
(mm)
CROSS SECTIONAL
AREA (mm
2
)
1
DC cable
PV cable complying with
1500V standard
6~9
4~6
2
Additional Grounding
cable
Outdoor singlecore copper
wire cable
-
3
AC cable
Four-core copper or
aluminum cable
38~56
L1,L2,L3,PE wire:70~240
4
Communication cable
Shielded twisted pair
5~8
1~1.5
Table 4-8 Cable requirements
*A copper to aluminum adapter terminal is required when an aluminum cable is used. For details, refer to "5.6.3
Aluminium Cable Requirements".
PE WIRE CROSS
SECTION
NOTE
S/2
(S: Phase wire
cross-section S)
The specifications are valid only when the phase wire and PE wire use the same material. If
otherwise, ensure that the cross section of the PE wire produces a conductance equivalent to
that of the wire specified in the table.
Table 4-9 PE wire requirements
4.4.3.1
Grounding requirements
All non-current carrying metal parts and device enclosures in the PV power system should be grounded, for
example, brackets of PV modules and inverter enclosure.
When there is only one inverter in the PV system, connect the additional grounding cable to a nearby grounding
point.
When there are multiple inverters in the PV system, connect grounding points of all inverters and the PV array
frames to the equipotential cable (according to the onsite conditions) to implement an equipotential connection.
4.4.4
Electrical connection
1)
Prepare the cable and terminal (Fig. 4-23).
WARNING
Since the inverter is a transformerless inverter, neither the negative pole nor the positive pole of the PV string
can be grounded. Otherwise, the inverter will not operate normally.
Connect the additional grounding terminal to the protective grounding point before AC cable connection, PV
cable connection, and communication cable connection.
The ground connection of this additional grounding terminal cannot replace the connection of the PE terminal
of the AC cable. Make sure those terminals are both grounded reliably.
