Technical data

5.3.2. Thin Film
The use of TripleLynx CN inverters with thin film modules has been approved by some manu-
facturers. Declarations and approvals can be found at www.danfoss.com/solar. If no declaration
is available for the preferred module it is important to obtain approval from the module manu-
facturer before installing thin film modules with the inverters.
The power-circuit of the inverters is based on an inverted asymmetrical boost converter and bi-
polar DC-link. The negative potential between the PV arrays and earth is therefore considerably
lower, compared to other transformerless inverters.
Module voltage during initial degradation may be higher than the rated voltage in
the data sheet. This must be taken into consideration when designing, since too
high a DC voltage can damage the inverter. Module current may also lie above the
inverter current limit during the initial degradation. In this case the inverter de-
creases the output power accordingly, resulting in lower yield. Therefore when de-
signing, take inverter and module specifications both before and after initial deg-
radation into consideration.
5.3.3. Lightning Protection
The inverter is manufactured with internal overvoltage protection on the AC and PV side. If the
PV system is installed on a building with an existing lightning protection system, the PV system
must also be properly included in the lightning protection system. The inverters are classified as
having Type III (class D) protection (limited protection). Varistors in the inverter are connected
between phase and neutral cables, and between PV plus and minus terminals. One varistor is
positioned between the neutral and PE cables.
Connection point Overvoltage category according to EN50178
AC side Category III
PV side Category II
Table 5.8: Overvoltage Category
5.3.4. Thermal Management
All power electronics equipment generates waste heat, which must be controlled and removed
to avoid damage and to achieve high reliability and long life. The temperature around critical
components like the integrated power modules is continuously measured to protect the elec-
tronics against overheating. If the temperature exceeds the limits, the inverter reduces input
power to keep the temperature at a safe level.
The thermal management concept of the inverter is based on forced cooling by means of three
speed-controlled fans. The fans are electronically controlled and are only active when needed.
The back side of the inverter is designed as a heat-sink that removes the heat generated by the
power semiconductors in the integrated power modules. Additionally, the magnetic parts are
ventilated by force.
At high altitudes, the cooling capacity of the air is reduced. The fan control will attempt to com-
pensate for the reduced cooling. At altitudes higher than 1000 m, derating of the inverter pow-
er at system layout should be considered to avoid loss of energy. As a rule of thumb the follow-
ing table can be used:
Altitude
2000 m 3000 m
Max. load of inverter 95 % 85 %
Table 5.9: Compensation for Altitude
5. Requirements for Connection
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