10 Maintenance
SMA Solar Technology AG
Operating manual
29
NA-BOX-12-3-20-BE-en-12
10 Maintenance
10.1
Inspection of Residual-Current Devices
Inspection interval for residual-current devices
The inspection interval for residual-current devices depends on the prevailing operating temperature.
• At prevailing operating temperatures of up to 40°C: inspect every 6 months.
• At prevailing operating temperatures of above 40°C: inspect every 3 months.
Instruction of end users
Because the protective cover remains in place during this test, testing is not hazardous and can be performed by
the end user. However, if the residual-current device does not trip, the NA-Box and the multicluster system must be
disconnected from voltage sources by a qualified person.
• Instruct the end user on the necessary procedure.
• Inform the end user that the inspection interval must always be complied with.
• Point out to the end user that if a defect is detected, a qualified person is required to perform the next steps.
Supply of loads temporarily disconnected during testing
During testing of the residual-current devices, the connection to the utility grid is temporarily disconnected. When
grid feed-in from a generator is discontinued, the supply of the loads is also interrupted.
• If the utility grid is connected, switch off sensitive loads prior to the test.
A
B
Overview of the residual-current device
Position
Designation
A
Test button
B
Switch lever
Top position: residual-current device is switched on.
Bottom position: residual-current device has tripped or is switched off.
Requirements:
☐ The utility grid must be connected to the multicluster system.
Procedure:
1. Stop the multicluster system at the master of the main cluster (see Sunny Island operating manual).
2. On the residual-current device
F228
press the [
TEST
] button.
3. If the residual-current device does not trip after pressing the button, perform the following steps:
