Installation and Operation Guide SOLECTRIA® PVI 25TL-208, PVI 50TL-480 and PVI 60TL-480
DOCR-071030-A (10/7/2022)
Page 17 of 131
WIRE BOX
INVERTER POWER HEAD
L1
L2
L3
N
PV1+
PV1+
PV1-
PV1-
MPPT1
MPPT2
AC
Output
PV Input
PV2+
PV2+
PV2-
PV2-
AC
Switch
Fuses
MPPT3
PV3+
PV3+
PV3-
PV3-
DC SPD
PV1+
DC Switch
Three
level
inverter
AFD
PV2+
PV3+
PV-
PE
Type
Ⅲ
MOV
Transmitter
Vin
GND
AC/DC Power
Supply
Figure 2-5 PVI 25TL-208 Inverter Schematic, Module-Level Rapid Shutdown Wire Box
Anti-islanding Detection
The SOLECTRIA PVI 25TL-208, PVI 50TL-480, and PVI 60TL-480 3-Phase String Inverters include unintentional
islanding detection as required by UL 1741/IEEE 1547. The inverter will continuously make bi-directional
perturbations to the frequency of the output current by injecting a small amount of reactive power to detect a
possible islanding condition. If the grid is stable, these small perturbations will have negligible effects on the
system voltage frequency. However, in an islanded condition the changes in reactive power will force the
frequency of the system voltage to deviate significantly, which will trigger the inverter to cease operation and
disconnect from the grid.
DC Ground Fault Protection
The inverters include residual current detection GFCI as part of the DC ground fault detection method required by
UL 1741. If there is a ground fault in the PV array, the ground fault detection circuitry will detect leakage current,
trigger an alarm, and the inverter will cease operation. See section 6.1.2.8 for further information regarding GFCI
Static and Dynamic trip thresholds and operation.
Surge Suppression
Table 2-1 Standard Waveform Peak Values
STANDARD WAVEFORM PEAK VALUES
SURGE CATEGORY
Ring Wave
Combination Wave
B
6kV/0.5kA
6kV/3kA
"Standard 1.2/50
μ
s - 8/20 us Combination Wave"
"Standard 0.5
μ
s - 100 kHz Ring Wave"
