Generac Power Systems PWRcell Reference Manual page 36

Section 6 PV Link and SnapRS
a. Ensure the configuration of panels connected
to the PV Link do not require PV Link settings
to be changed.
2. Check PV Link Settings
a. Ensure PV Link was enabled w/PVRSS upon
commissioning. If not, disable and select
'Enable w/PVRSS'.
b. If 4 or fewer 60 cell type solar panels,
determine whether Vin Startup value should be
lowered.
c. If installing 96 cell type solar panels using two
parallel substrings to the input of one PV Link,
ensure 'Sting Count' has been adjusted to a
value of '2'.
d. Verify 'SnapRS Installed' match the number of
'SnapRS Detected'.
3. Override PVRSS
a. If still unable to resolve, temporarily override
PVRSS to see if PV Link will make power
without relying on its SnapRS count.
b. If the PV Link begins making power, this
indicates a SnapRS count issue.
c. If the PV Link does not begin making power,
there is a PV wiring issue. This may also
indicate that the SnapRS enable signal is not
able to transmit through the PV substring(s).
Check for open circuits, wiring issues, or
damaged PV modules.
4. Measure Substring Voltage w/SnapRS
a. Disable the PV Link from the inverter screen.
b. Unplug the PV input +/- and measure DC
voltage of substring.
c. Voltage should not exceed the Voc of one solar
panel.
d. Voltage should not be 10 volts lower than the
Voc of one solar panel.
e. If value is above or below where it should be,
check PV wiring and number of SnapRS
installed.
(Voc * number of panels) / (1 + number of SnapRS)
Ex. (40.1 * 8) / (1 + 8)
320.8 / 9
5. PV Wiring
a. Low sun is either a settings issue or a PV
wiring issue; it is not an issue with REbus
wiring.
b. Check for loose connections, faulty MC4
crimps, strained wire management.
6. SnapRS Health Check
a. Visually inspect SnapRS devices for any
deformities.
32
= 35.64
b. Perform health check measurements on
SnapRS devices as necessary.
No PV Link Device Comms
If upon commissioning, PV Link does not show up with a
device page on the inverter screen, there is an issue with
the Power Line Communications—likely a wiring mistake
on REbus. See also Inverter Troubleshooting
1. DC Disconnects
a. Ensure DC disconnects are closed in the ON
position for PV Link in question. REbus voltage
must be present at the PV Link for it to
communicate with the inverter.
b. Always disable the inverter before turning DC
disconnects ON.
2. REbus Wiring
a. This problem is most commonly a polarity
issue. Check REbus wiring to ensure correct
polarity.
b. If polarity checks out, check the REbus ground
connection. Make sure PV Link is grounded
back to the inverter.
c. If polarity and grounding are correct, verify
each REbus home run circuit is consistent so
that the positive from one home run is not
paired with the negative of another. See
REbus DC Wiring
details.
Known PV Link 'Offline'
If a PV Link that has been communicating previously with
the inverter shows up as 'offline', this is a result of losing
Power Line Communications.
Troubleshooting.
1. DC Disconnects
a. Ensure DC disconnects are closed in the ON
position for PV Link in question. REbus voltage
must be present at the PV Link for it to
communicate with the inverter.
a. Always disable the inverter before turning DC
disconnects ON.
2. PV Link Settings
a. Verify that the PLM Channel matches the
inverter by navigating to the inverter device
page.
b. If only one PWRcell inverter on site, access the
'mod. settings' menu for the inverter and
change the PLM channel to 0.
c. Channel 0 is a catchall channel and will pick up
devices that may be set to other channels. Be
certain to de-energize any other PWRcell
inverter systems on site before setting to PLM
0.
table.
in this section for more
See also Inverter
Diagnostic Repair Manual