SMA SMC 5000 Installation - Manual (Page 47)

SMA Technologie AG Exchanging Varistors
Installation Guide SMC50_60-11:SE2006 Page 47
9 Exchanging Varistors
The Sunny Mini Central 5000/6000 is a very complex technical device. Therefore
there are only a few possibilities to repair failures on site. Please do not try to make
repairs otherwise than described in this document. Make use of our exchange service
and the repair service of SMA Technologie AG.
If the red status LED is permanently on during operation please first make sure that
there is no ground fault in the PV generator.
4. If the voltages measured are constant and their total is approximately equal to
the open-circuit voltage of the string, there is a ground fault in this string. Its ap-
proximate position can be deducted from the ratios of voltages.
1. Disconnect the grid (switch off the circuit break-
er), secure it against accidental reactivation and
ensure that it is disconnected.
Ensure that the AC voltage is off before
you open the Sunny Mini Central 5000/
6000!
2. Disconnect the PV plug connectors of all strings.
Disconnect the PV strings!
3. Measure voltages between one PV plug connec-
tor of each string and the ground potential. Fol-
low all applicable safety instructions!
Measure voltages between PV plug
connectors and the ground potential.
The voltage from the strings is very dangerous! Be very careful
and pay attention to all applicable safety regulations!
1. 2. 3.
Off!
String A
String B
+ + - -
PE