Auxiliary Transformer - Ingeteam INGECON SUN PowerMax TL B Series Installation And Operation Manual

Preparation for installing the unit
3. PV fields connected by these inverters to the same transformer must have the same voltage settings.
4. The short circuit voltage of a transformer should not be greater than 8% between the primary winding and
secondary winding(s).
5. We recommend inserting a grounded metal screen between the high voltage winding and low voltage
winding.
6. The low voltage winding must withstand pulsating voltage components with dU/dt of 500 V/uS voltage.
Because of inverter operation, the voltage between a phase and ground can reach 3/2 of the open circuit
voltage of the PV array.
7. We recommend using the Dy11 connection.
8. The connection to the medium voltage grid will be the nominal connection point.
9. We advise using transformers equipped with five-point voltage regulators, with the possibility of selecting
the following options:
10. The impedance of the inverter's transformer (Zmv) must be calculated according to the breaking capacity
of the inverter's thermomagnetic circuit breaker. Depending on the AC voltage of the inverter, its
thermomagnetic circuit breaker supports the following rated short circuit current (Ik):
The following table outlines the transformer's short circuit voltage according to the inverter's AC voltage
and the number of inverters connected to the same transformer. The transformer's short circuit voltage
(Ucc) must be equal to or greater than the ones shown in the following table:
AC voltage
Up to 450 Vac
460 ~ 690 Vac
No electronic equipment may be connected to the power grid. All auxiliary loads must be isolated from the power
grid via a galvanically isolated transformer, as shown in the section "6.8.2. Auxiliary transformer".
CAUTION
The distance between the inverter and the transformer must not be greater than 30 meters.

6.8.2. Auxiliary transformer

Some unit components such as fans, contactors or power supplies, require auxiliary power to operate. No electronic
equipment may be connected to the power grid. All auxiliary loads must be isolated from the power grid via a
galvanically isolated transformer.
This is why it is essential to install an auxiliary services transformer with galvanic isolation, suitable for the grid
with a single phase voltage of 220 V 50/60 Hz.
CAUTION
The Auxiliary service transformer must have galvanic insulation. It is forbidden to use autotransformers or other
devices without galvanic isolation to match the grid voltage to the single phase voltage required for the proper
operation of the unit.
Ingeteam accepts no liability for any consequences arising from non-compliance with these instructions.
It is possible to install the auxiliary services kit, and if you prefer you may install an auxiliary transformer acquired
from third parties. In this last example, you should follow the following guidelines.
ABQ2026IQE01_A - Installation and Operation Manual
5% 2.5%
AC voltage
Up to 450 Vac
460 ~ 690 Vac
Minimum Ucc depending on the number of inverters connected to the same transformer
1 inverter
1.9%
2.3%
0% -2.5%
Ik
85 kA
65 kA
2 inverters 3 inverters
3.8% 5.6%
4.6% 6.9%
-5%
4 inverters
7.5%
9.2%
Ingeteam
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