Checking The Earthing - VOLTWERK SmartConnect 8 Instrucciones De Servicio

8.3
Result
SmartConnect
Operating manual

Checking the earthing

Prerequisites
The DC disconnect is switched off (Off).
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You have ensured that the device is voltage-free. Switching the DC
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disconnect to Off does not guarantee that the device is free of voltage.
The central inverter is isolated.
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The optional external string switch-off system is isolated.
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The mains cable is not under voltage.
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Additional safety measures have been checked and put in place where
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necessary.
Required measuring devices
Test device for earthing resistance. Note the following:
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All measuring devices and cables must have protection class CAT II
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(1000 V) in accordance with EN 61010-1.
Check the earthing.
1. Check the earthing of the SmartConnect. Note the following:
The housing must be connected to the reference earth of the
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system (protective earth connection).
Laying the earth from the auxiliary voltage supply is not sufficient.
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The earthing connection must be connected to the outside of the
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housing.
Check the tightening torque on the earthing connection (tightening
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torque 25 Nm).
Check the earthing resistance.
The earthing resistance is the electrical resistance between the protective
earth connection and the reference potential of the ground.
Earthing resistance is measured by running an alternating current over the
earthing conductor, the earth electrode and the earth-spreading resistor. It
can be measured either directly or indirectly.
 U
R /I .
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A L F
R Earthing resistance (protective earth).
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A
U Contact voltage.
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L
I Residual current.
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F
2. Check the earthing resistance. Note the following:
R < 3 .
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3. If R > 3 , correct the earthing.
The earth connection has been inspected.
For direct measurement, an earth probe is required. For indirect
measurement, the approximate earthing resistance is determined using an
'earth-electrode loop resistance measurement', without the use of a probe.
8 Maintenance
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