10 Maintenance
SMA Solar Technology AG
Operating manual
31
NA-BOX-12-3-20-BE-en-12
To test the functionality of the tie switch and therefore to ensure that islanding detection is functioning, the tripping
function of the tie switch must tested every six months. Both impact chains must be tested since the islanding detection
function is redundant. Opening the NA-Box tie switch
Q202
simulates a stand-alone grid, resulting in the Sunny Island
detecting an undesired stand-alone grid, switching to the "stand-alone grid" operating state and opening the NA-Box
tie switch
Q201
.
INFO
TEST
RESET
MENU
ESC
A
B
Figure 10: Test buttons for tripping the tie switches
Position
Designation
A
Test
button on the grid and PV system protection device
B
Test button
S220
Requirement:
☐ The LEDs
ALARM1
and
ALARM2
on the grid and PV system protection device must be off (see grid and PV
system protection device documentation).
Procedure:
1. Press and hold the
Test
button for at least five seconds.
☑ The NA-Box tie switch
Q202
opens. The Sunny Island inverter detects a stand-alone grid within five seconds
and switches to the operating state "stand-alone grid" and opens the NA-Box tie switch
Q201
.
✖ The tie switch
Q202
does not open or the Sunny Island inverter does not react?
• Disconnect the NA-Box and multicluster system from voltage sources (see Section 8, page 23).
• Contact the Service (see Section 13, page 38). This will trigger the requisite spare parts order.
2. Release the
Test
button and wait for at least 30 seconds.
☑ The NA-Box tie switch
Q201
closes, the Sunny Island inverter switches to the operating state "grid feed-in"
and closes the NA-Box tie switch
Q202
.
✖ The tie switch
Q201
does not close?
• Disconnect the NA-Box and multicluster system from voltage sources (see Section 8, page 23).
• Contact the Service (see Section 13, page 38). This will trigger the requisite spare parts order.
3. Repeat the test for the impact chain using test button
S220
. To do so, use the same procedure as described for
the Test button.
4. Document the test result in accordance with the locally applicable standards and directives. This is your proof that
regular inspection has taken place.
