Diagnostics - Generac Power Systems PWRcell Reference Manual

Diagnostics

PV Link Universal
1. PV Panel Configurations
•
Confirm solar panel type. If using 96 cell type solar
panels, reference
follow the instructions in the Generac PV Link
Installation Manual for paralleling the inputs of two
series substrings.
•
Verify input voltage is not too high or too low for PV
Link.
– Input voltage range is 60–420 Voc.
– Default minimum start up voltage is set to 135
Voc. Ensure Vin Startup is adjusted appropriately
in the 'mod. settings' menu for the PV Link if
input voltage will be lower than 135 Voc (typically
required for substrings of 4 or fewer 60 cell type
solar panels).
•
Use PV Link String Sizing Worksheet to determine
how many panels of a specific make and model
may be put into one PV Link in a given region.
2. REbus DC Wiring
•
Check REbus wiring polarity. Power Line Commu-
nications will not function if polarity is reversed
between PV Link and Inverter.
•
Check REbus ground. Power Line Communica-
tions will not function properly between the PV Link
and Inverter with poor grounding or if grounding
wire layout is subject to reflections. Avoid ground
loops and complex "Y" or "Star" configurations in
ground wires.
•
Check for loose connections at inverter and PV
Link(s). Ensure the inverter is disabled before dis-
connecting wiring or performing tug-tests.
•
Verify each REbus home run circuit consists of its
own unique positive, negative, and ground wire. It
is recommended to label both ends of each run
during installation to avoid confusion. If suspected
mismatching has occurred, use a DMM to "ring" out
the runs using the continuity function.
•
To rule out shorted wiring, with DC disconnects in
the OFF position, use a digital multimeter (DMM) to
verify resistance is greater than 10 kΩ for each cir-
cuit.
3. DC Disconnects
•
Verify DC disconnects are closed in the ON posi-
tion. REbus voltage must be present at PV Links
for them to communicate with the inverter.
•
Always disable the inverter before turning DC dis-
connects ON.
Diagnostic Repair Manual
above and
Parallel Substrings
Section 6 PV Link and SnapRS
4. Disable/Enable
•
For non-terminal errors, disabling and re-enabling
the PV Link from the inverter control panel may
clear the error state and allow the PV Link to return
to operation.
PV Link Only (No SnapRS) (NEC 2014 and older)
1. PV Link Settings (see
•
Do not enable the PV Link using the "Enable w/
PVRSS" option if no SnapRS devices are installed.
•
Verify Vin Startup is adjusted appropriately in the
'mod. settings' menu for the PV Link if input voltage
will be lower than the default 135 Voc (typically
required for substrings of 4 or fewer 60 cell type
solar panels).
•
Verify the PLM channel of the PV Link matches the
inverter. If there is only one inverter on-site, leave
all devices set to default at channel 1.
– To find a device that has been set to a different
channel than the inverter, navigate to the inverter
'mod. settings' menu and set the inverter PLM
channel to 0 temporarily. Channel 0 is a catch-all
channel.
NOTE: For multi-inverter system sites, take precautions
to completely de-energize all other inverter systems
before selecting channel 0 on a given inverter for
troubleshooting.
NOTE: Do not leave the inverter on channel 0. See
Appendix B Inverter for details on
System Commissioning Procedure
talk Recovery Procedure.
2. Measuring Substring Voltage
•
After substring has been wired, use a DMM to
measure cumulative substring voltage before plug-
ging PV positive and negative into PV Link.
•
If voltage is not present, check PV wiring for loose
connections.
•
If a short is suspected, measure PV positive to
ground, then measure PV negative to ground. If
more than one volt is measured positive to ground,
negative to ground, a short is likely present on the
substring wiring.
3. PV Wiring
•
Verify PV wiring is connected to the 'Input' side of
the PV Link.
•
Verify REbus wiring is connected to the 'Output'
side of the PV Link.
•
Verify PV connection points are making good con-
tact.
•
Unplug and plug back in or remake connections if
connection is poor.
•
Verify wire management is not pinching PV wires.
•
Verify PV wires are not too tight between connec-
tion points.
Appendix D PV Link)
Multiple Inverter
and
PLM Cross-
27