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9 Maintenance and Service
9.1 Maintenace
The PV AC combiner box is a product with mini-
mum maintenance.
►
Carry out a visual inspection once per year
checking the issues listed below.
DANGER
Imminent risk of life!
High voltages up to 800 V AC are present in
the live parts.
►
Ensure that string inverters connected to
the AC Combiner box are switched off and
that then combiner box is free of hazard-
ous voltage
Check list for the annual inspection of the PV AC combiner box
Remarks
Issue
Checked
Enclosure and seals
Temperature fluctuations on outdoor sites strains the
seals.
► Check that the cover seals are in proper condition.
Porous or squeezed seals decrease the tightness
and therefore the IP class of the enclosure.
► Check that there is no or dust inside the enclo
-
sure.
Humidity inside the enclosure can cause corrosion.
► Check the seals and screw connections as well as
the drainage inserts.
► Check that there are no signs of corrosion, water
or humidity inside the enclosure.
Regard the tightening torques in the specific docu
-
mentation inside each PV AC combiner box.
► Check the cable glands and retighten them if
needed.
Surge protection arresters (optional)
The inspection windows of the surge arresters should
be green.
►
Replace each surge arrester the inspection win-
dow of which is red.
PV AC
combiner boxes have a mark on all screws
and nuts to indicate the torque position. If the mark is
unchanged since the previous inspection, there is no
loss of torque.
Regard the tightening torques in the specific docu
-
mentation inside each PV AC combiner box.
► Check if any of the marks on screws and nuts
have been changed.
►
Retighten the screws if needed.
Fuses
Blown fuses diminish the yield of the PV plant.
► Check the continuity of all fuses.
AC switch
PV AC combiner boxes have
a mark on all screws
and nuts to indicate the torque position. If the mark is
unchanged since the previous inspection, there is no
loss of torque.
Regard the tightening torques in the specific docu
-
mentation inside each PV AC combiner box.
► Check if any of the marks on screws and nuts
have been changed.
►
Retighten the screws if needed.
