Generac Power Systems PWRcell Reference Manual page 21

No REbus Device Comms
1. Device Does Not Appear on Screen
a. The most common reason for a device not to
appear at the screen is due to reverse polarity
of positive and negative REbus wiring. Devices
communicate with the Inverter over the REbus
power lines. Polarity must be correct. Check
polarity of REbus wiring at the device and at
the inverter.
b. Check grounding. REbus ground is required
for common mode voltage on the power lines
which allows for PLM comms. Verify each
device has an uninterrupted ground connection
between it and the Inverter.
2. 'N/A' on Device Icons
a. If at the home screen the solar panel icon or
battery icon display 'N/A', this means there is
no communication with the Inverter from those
devices.
b. Allow the screen to update. The screen will
exhibit a certain amount of delay in the
information it displays from the system,
especially after a change has been made.
c. Verify the DC disconnects for the connected
devices are in the ON position and REbus
voltage is present at the output terminals of the
DC disconnects.
d. Verify the Inverter is enabled to be able to
communicate with devices. Devices will show
as 'offline' on their respective device pages.
e. Verify PLM_Disable setpoint for inverter is set
to 'off.'
f. If all of the above checks out, power cycle the
inverter.
g. Re-energize the inverter. This allows for the
internal processor to be reset. If comms do not
return at this point, call Generac PWRcell
Technical Support.
3. Known Device Offline
a. Verify the inverter is enabled and REbus
voltage is at least 360 VDC out to the devices.
b. Verify this device is still connected to the
Inverter.
c. Verify PLM_Disable setpoint for inverter is set
to 'off.'
d. Verify the DC disconnect for this device is in
the ON position.
e. Inspect wired connections for any loose wires.
NOTE: Ensure the
disconnecting wiring or performing tug-tests.
f. Verify polarity and grounding.
4. PLM Channel Configuration
Diagnostic Repair Manual
inverter is disabled
a. For sites with one inverter, leave PLM channel
set to default value of 1 for all devices.
b. For sites with more than one inverter,
reference
Systems
c. Verify that each Inverter system is using its
own unique PLM channel across all connected
devices.
NOTE: Do not leave any devices or inverters on channel
1 or channel 0 at multiple inverter sites.
Beacon Device Page Missing
See
Internet Troubleshooting
No Backup Power
If the utility grid goes down and the system does not
provide backup power:
1. Verify the Protected Loads breaker is in the ON
position.
a. Cycle the Protected Loads breaker OFF then
back ON.
2. Check Protected Loads Panel.
a. If the protected loads panel has its own main
breaker, verify this breaker is ON.
3. Check Inverter Settings
a. Verify a backup system mode has been
selected (e.g. Clean Backup, Self Supply,
Priority Backup)
b. Verify that the islanding setting, 'EnaIslanding'
is set to 'on' in the 'mod. settings' menu for the
inverter.
c. If system has been installed with an external
transfer switch, ensure the setting,
'NumTranSwtchs' is set to reflect the number
of PWRcell ATS connected to the inverter
system in the 'mod. settings' menu for the
inverter.
4. AC Wiring
a. Verify the AC grid connection wiring (top AC
terminals at Inverter) has not been swapped
with the Protected Loads wiring (bottom AC
terminals at Inverter).
(1) Turn the Protected Loads breaker OFF.
(2) Turn on AC power to Inverter.
(3) If AC voltage is measured at Protected
b. If system has been installed with an external
transfer switch, verify all wiring to and within
before
the transfer switch.
5. Check PWRcell Battery
a. See
Section 4 PWRcell Inverter
Commissioning Multiple Inverter
in Appendix B Inverter.
Flowchart.
Loads terminals, wiring is reversed.
PWRcell Battery Section for more details.
17