Electrical Connections
Installation Manual for Generac PWRCell Inverter
21
Connecting CTs to Multiple PWRcell Systems /
Inverters
When an installation has multiple PWRcell inverter
systems, either:
•
Run a set of CTs for each inverter.
•
Run a set of CTs to one inverter and then run a Cat
5 cable from the spare CT port within that inverter
to any CT port within a second inverter.
NOTE:
One set of CTs may be utilized for up to two
inverters.
When running separate sets of CTs for each inverter, the
load value displayed on each inverter screen will be the
total load measured by the CTs.
When daisy-chaining two inverters, the total measured
value is shared evenly between the inverters.
NOTE:
Daisy-chaining CTs between two inverters for
distributed load-share is most applicable when each
inverter has a battery attached. Otherwise, this
configuration may not be necessary or desirable.
To daisy-chain a CT signal:
1.
Connect and calibrate a set of CTs to the first
inverter.
2.
Run a new Cat 5 cable between the spare CT
accessory port of the first inverter to either CT
accessory port on the second inverter.
3.
Set GridParInvrtrs to a value of 2. See
below.
NOTE:
Running a new Cat 5 cable between inverter CT
ports prior to calibration in Step 1 may cause calibration
issues.
CT Calibration
•
Install CTs before powering ON the inverter.
•
The inverter automatically detects CTs when
turned ON.
•
Once CTs are detected, a utility pole symbol will
appear on the lower right corner of the home
screen power flow diagram. Verify operation by
noting power flow.
– To calibrate CTs, navigate to the inverter device
page, access the sub-menu, and select the Cali
-
brate CTs option. When the CT calibration pro
-
cess is successfully complete, the inverter
screen will provide feedback showing ct cal suc
-
cess. Otherwise, the screen will show ct cal = X,
where the value of X can be found in
Automatic Detection Troubleshooting Table
– CT1 must be connected to Line 1.
– CT2 must be connected to Line 2.
– CT3 must be connected to line 3 (for three phase
applications).
– All CTs must be orientated in the same relative
direction.
– In certain scenarios, additional setpoint modifi
-
cations may need to be made. See
for more information.
Table 5-10. CT Setpoints
Setpoint
Behavior
Default
Units
CalOverride
•
Overrides CT calibration.
•
When set to OFF, the inverter detects the CTs number and direction of
CTs.
•
A value of ON assumes a specific orientation and direction of CTs.
OFF
N/A
CTTurnsRatio
•
Turns ratio of the CTs installed.
•
Default turns ratio of 1,500 is compatible with included clamp type CTs.
•
If installation restriction requires larger accessory CTs, set point shall be
adjusted to 3,000. Verify turn ratio of CTs before modifying this setting.
1,500
Turns
GridParInvtrs
•
Allows two inverters to share one set of CTs.
•
If set to “1”, only one inverter should be using a single set of CTs.
•
If set to “2”, two inverters can share one set of CTs.
1
N/A
