INSTALLATION - COMMISSIONING
50
INSULATION RESISTANCE TEST
This test is performed to verify the insulation resistance between the positive DC string wiring and earth and
the negative DC string wiring and earth are both greater than or equal to 1 Megaohm (1 MΩ) as required by
AS/NZS 5033:2012 clause D4.
An insulation tester capable of applying test voltages of 500V and 1000V is required to perform this test.
Warning:
Live voltages of up to 600 VDC will be present during this test. Wear personal protective
equipment to prevent the risk of electric shock and treat DC string wiring as if it were live at all times.
Warning:
Do not permit any person to touch any part of the array whist the insulation test is being
performed.
1.
Ensure that the Inverter AC Isolator is in the OFF position.
2.
Switch the Rooftop DC Isolator(s) to the ON position.
3.
Switch the Inverter DC Isolator(s) to the OFF position.
4.
Disconnect string positive and negative DC plug connectors from inverter.
5.
Connect the insulation tester leads between the disconnected positive string plug and earth. Ensure test
leads are firmly fixed in position.
6.
Select the appropriate test voltage on the insulation tester according to the number of modules in the
string (500 V for a string of 6-10 modules; 1000 V for a string of 11-14 modules).
7.
Switch the Inverter DC Isolator to the ON position.
Warning:
The positive and negative string wiring is now live and will have up to 600 VDC present.
8.
Activate insulation tester. The resistance measured must be greater than or equal to 1 M
Ω.
9.
Switch the Inverter DC Isolator to the OFF position.
10.
Connect insulation tester leads between the disconnected negative string plug and earth. Ensure test
leads are firmly fixed in position.
11.
Switch the Inverter DC Isolator to the ON position.
Warning:
The positive and negative string wiring is now live and will have up to 600 VDC present.
12.
Activate insulation tester. The resistance measured must be greater than or equal to 1 MΩ.
13.
Switch the Inverter DC Isolator to the OFF position.
14.
Reconnect string positive and negative DC connectors to the inverter.
15.
For the Two String Configuration, repeat this procedure for the second string.
VERIFICATION OF INVERTER WIRING
This verification is performed to ensure the inverter is correctly and safely wired.
Check the Positive and
Negative connectors are fully engaged at the Inverter and any unused inputs have connectors with sealing
plugs installed.
INVERTER COMMISSIONING
Warning:
Do not turn on the inverter until all of the previous commission procedure tests/checks have
been satisfactorily completed.
Turn on the PV system (refer to “To Turn PV System On” on page 5) then commission the inverter according
to the commissioning procedure described in the relevant inverter installation guide for the model inverter
installed.
For Power-One/ABB inverters the start voltage must be correctly set based on the type and size of array to
allow the system to perform correctly. To set the start voltage refer to “Power-One/ABB Inverter Start
Voltage” on page 51.
