Generac Power Systems PWRcell Reference Manual page 30

Section 6 PV Link and SnapRS
Substring
Each substring will connect to one PV Link. Up to three substrings can be paralleled back the inverter on one REbus
home run. The number of solar panels going into one PV Link can typically be anywhere from 2–9 with a minimum
substring input Voc of 60 VDC and a maximum Voc of 420 VDC. The number of solar panels will depend on
manufacturer's specifications for make, model and local factors, such as temperature. The maximum quantity of
SnapRS per substring is 10 devices total. Follow permitted plan-set for building site and reference the PV Link Sizing
Tool at https://www.generac.com/resources-and-tools/ce-installer-resources/system-sizing-tools.
A
H
Parallel Substrings
Parallel substrings are two series substrings, matching in quantity of solar panels, paralleled to the input of one PV
Link. Parallel substrings will be necessary for use with 96 cell solar panels to keep the input voltage below 420 Voc.
See 6-4. When dual substrings are connected in parallel, each substring must use the same number and type
Figure
of PV modules. When using parallel substrings with SnapRS, the 'String Count' setting on the PV Link device page
must be set to 2. See Table D-1
A
F
Figure 6-4. Single PV Substring with Parallel Series Inputs and SnapRS Devices
IMPORTANT NOTE: Installing a number of panels that will generate in excess of 420 V will permanently dam-
age the PV Link.
NOTE: substrings will need to include SnapRS where NEC adoption is 2017 and higher.
NOTE: Total substring voltage can be measured using a digital multimeter (DMM) before plugging positive and
negative into the PV Link, only if SnapRS are not installed. If SnapRS are installed, cumulative string voltage cannot be
measured. See SnapRS Diagnostics.
26
E
B C G
F
D
G
Figure 6-3. Single-String PV Substring with SnapRS Devices
A PWRcell Inverter
B REbus homerun
C REbus Output -
D REbus Output +
in Appendix D PV
B C
E
A PWRcell Inverter
B REbus homerun
C PV Link
E PV Substring Input -
F PV Substring Input +
G SnapRS Device
H PV Panel
Link.
D
D
D MC4 branch connector
E SnapRS Device
F PV Panel
011990
010029
Diagnostic Repair Manual