Weidmuller 2008130000, Руководство пользователя

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CAUTION
Some parts of this equipment may be hot and create burns to people
even when no current is flowing through X1/X4 and the negative copper
busbars. If the wires connected to these terminals are not properly
tightened up, the risk of burns is significantly higher. After disconnecting the
voltages/currents of X1/X4, X2 and the negative copper busbars, wait at
least 15 minutes.
CAUTION
Take the necessary precautions regarding electrostatic discharge when
manipulating this device.
2.3 Intended use
This equipment is meant to be permanently installed inside a PV combiner box with
the purpose of monitoring DC voltage and current plus some additional field variables
(internal temperature and two digital inputs). The measured values can be accessed
from a Modbus RTU client (typically a Scada or a PLC) via a RS–485 cable.
The accurate measurements performed by this device have multiple uses. The list below
is not meant to be exhaustive:
• Detecting blown fuse-links: if the current of one input drops to zero permanently
during daylight this is a clear indication of a blown fuse (or a more severe DC issue
such as a broken wire, a damaged PV module, etc.)
• Detecting reverse current: if the current of one input drops to zero only during
certain periods of daylight but it recovers after a while, this could be due to the fact
that in reality the current is momentarily becoming negative. Negative current is
reverse current.
• Detecting underperforming strings (due to module mismatching, shading,
defects, etc.): some very obvious cases can be detected by just inspecting instant
current measurements, but it is recommended to use DC performance ratio
(R
P
, see IEC 61724) calculations to find “hidden” underperforming strings.