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3. A less likely cause is limited to multiple inverter installations, when
the positive and negative array strings are crossed. Crossed wires occur
when a positive or negative conductor from array 1 is connected with
wires in array 2. An example is if inverter A has the positive conductor
from array 1 and the negative conductor from array 2 connected.
4. If the fuse is open, then a ground fault condition exists.
• Check the DC voltage between the grounded terminal of the array
and earth ground.
• The voltage should be less than 25 VDC with the GFI fuse re-
moved. If the voltage is greater than this, check the array wiring as
there may be a ground fault. For the best results, perform this test
with the disconnect on and off. If you are not comfortable conduct-
ing this test, DO NOT ATTEMPT IT. (See Chapter 7,
• If a ground fault condition is not present because it is now re-
paired or intermittent, replace the fuse with a similar fuse rated at
600VDC and 1A.
Note:
Replace the GFI fuse with the same type and rating of
fuse. The inverter uses Littlefuse KLKD1 1A/600VDC.
5. Make sure the grounded leg of the PV array is not broken in the
disconnect.
NOTE: The GFI is a latching circuit which prevents the inverter from
operating until the fault is repaired and the inverter is reset.
The inverter will not operate, even if the fault is repaired,
unless it is manually reset by turning the disconnect off and
then on.
6.2 Displayed Fault Codes
The vacuum fluorescent display (VFD) provides the codes shown in
Figure 6-1 and Figure 6-2 when a fault has occurred.
Screen 1
Screen 2
Screen 3
Figure 6-1 Faulted
