18
Figure 4.12 PV cable connection
4.6 PV Cable Installation
Please verify the following before connecting the PV strings to the inverter:
Ensure the DC voltage of the PV strings will not exceed the maximum DC input
voltage (600Vdc). Violating this condition will void the inverter warranty.
Ensure the polarity of the PV strings are correct (ex: positive is positive)
.
Ensure the DC-switch, battery, AC-BACKUP, and AC-Grid OCPDs are all off.
Ensure the PV resistance to ground is higher than 20K ohms.
Ensure that the Isc of the strings will not exceed the maximum DC input current.
CAUTION:
If the DC conductors are accidently connected in reverse or if the inverter is
not working properly, do NOT close the DC switch. Otherwise, it may
cause a DC arc and damage to the inverter or a fire.
The steps for corrective actions are as follows:
*Use a DC amp clamp multimeter to measure the DC string current.
*If the current is above 0.5A, please wait for the irradiance on the PV array to
diminish until the current drops below 0.5A.
*Once the current is below 0.5A, you are allowed to open the DC switch and
and then disconnect the PV strings from the inverter.
*
In order to completely eliminate the potential for failure, leave the PV strings
disconnected until the cause of the reverse polarity is corrected.
4. Installation
1. Insert a technician screwdriver
into the square hole above the terminal
2. Push down with the screwdriver and
watch the terminal open up
Note: Each PV string input is
a separate MPPT
3. Strip 1/2 inch off the ends of each PV cable. Insert the PV cable into the terminal
4. Pull the screwdriver out, the terminal will clamp down on the PV wire.
5. Give the PV wire a gentle tug test to ensure that the connection is tight.
Danger:
Before installing the PV cables, be sure that the PV array is disconnected.
Use a multimeter to verify that the PV string voltages are 0V before proceeding.
If rapid shutdown is being used, then under 30Vdc per string is safe.