Installation and Operation Guide SOLECTRIA PVI 25TL-480-R
DOCR-071030-A (11/17/2020)
Page 30 of 101
NOTICE!
DC Overload:
Exceeding the recommended DC to AC ratio may damage the inverter and will void the warranty.
Size strings according to information in this section and all applicable electrical codes.
DC/AC Ratio and Current Limits:
Both DC to AC ratio and I
sc
limits must be observed. Failure to meet these requirements
may result in damage and will void the warranty.
NOTICE!
High Irradiance Installations:
In applications that may experience higher than 1000 W/m
2
on a regular basis, it is
recommended to design a DC-to-AC ratio below the limit of 1.5.
String Mismatch
3.4.2
To ensure optimal performance, the number of PV modules per source circuit should be identical within a given MPPT
zone. However, PV input power may be unbalanced between the two MPPT zones. See Figure 3-15 for string/zone
combinations.
DESIGN TIP #1: The max input power per MPPT zone is 22kW. The total inverter max PV power is 37.5kW.
DESIGN TIP #2: When designing the PV system, ensure each PV source circuit within a single PV input zone
includes the same module type (manufacturer and rating), series module count, and module orientation (tilt and
azimuth) to maximize MPPT performance and energy harvest.
DESIGN TIP #3: The difference in the number of source circuits for each MPPT should not exceed one (i.e.
PV_In1:PV_In2 = 3:2). Uneven distribution of strings among the two MPPTs (e.g. PV_In1:PV_In2 = 3:1) is not
recommended and may result in unnecessary power clipping.
Figure 3-15 Independent MPPT Zones Only
WARNING
Unequal String Lengths and Module Mismatch:
Opening fuses under load can cause a hazardous condition. It is strongly
recommended to avoid unequal string lengths within a zone and module mismatch.