IV431E REV. 00 Issued: 2020/11/16 User Manual Soleil SPX 200K-250K
Pag. 40 of 76 +FR
No load can be connected between the inverter and the breaker.
Medium-voltage transformer
The configured medium-voltage transformer must meet the following requirements:
l
The selected transformer can be distribution transformer, which matches the PV system of typical
periodicity load (that is to say, in daytime, there is load, at night, there is no load). You can choose
dry type transformer or oil-immersed transformer, shielding winding is not required.
l
The line voltage at low-voltage side of the transformer must meet the output line voltage of
inverter's AC side. When connecting with IT type grid, the ground resistance requirements of the
winding at low-voltage side of boost transformer, AC wires and secondary device (including relay
protection device, detection meter and related auxiliary equipment) must not less than 1100V.
l
The output line voltage at high voltage side of the transformer must be in accord with the voltage
level of local grid. We suggest selecting the transformer with tapped switch at the high voltage side.
l
When the temperature around the transformer is 45
ć
, the transformer should be able to operate
for a long time under 1.1 times overload. The selected transformer must be with overload protection
and short circuit protection.
l
It is recommended to use the transformer whose short circuit impedance equal to 6% (allowable
error
f
10%), and at the same time, the voltage drop of system wires should be not more than 3%.
l
The bearable DC component of the transformer should be 1% of the fundamental current in rated
power.
l
The apparent power of inverter cannot exceed the power of the transformer. Considering the max.
AC current of all paralleled inverters.
l
Considering the bearable ability of the transformer if system faults. The fault includes system short
circuit, grounding fault, voltage drop, etc.
l
When selecting and installing the transformer, the environment condition, such as temperature,
humidity, altitude, air quality, of local site must be taken into account.
Terminal requirements
l
When the AC output uses copper wire, it is recommended to use DT/OT terminals (as shown in
Figure3-29). The terminal specifications and requirements is: 13mm
İ
A
İ
15.5mm, B
İ
46mm, C
İ
22mm.
