3 Mounting and Commissioning
238
7ST6 Manual
E50417-G1176-C251-A3
3.2.2
Checking System Connections
WARNING!
Warning of hazardous voltages
Non-observance of the following measures can result in death, personal injury or sub-
stantial property damage.
Only qualified people who are familiar with and observe the safety procedures and
precautionary measures shall perform the inspection steps.
Caution!
Be careful when operating the device connected to a battery charger without a
battery
Non-observance of the following measure can lead to unusually high voltages and
consequently, the destruction of the device.
Do not operate the device on a battery charger without a connected battery. (For limit
values see also Technical Data, Section 4.1).
If undervoltage protection is configured and enabled in the device and if, at the same
time, the current criterion is disabled, the device picks up right after auxiliary voltage
has been connected, since no measuring voltage is available. To make the device con-
figurable, pickup is to be stopped, i.e. the measuring voltage is connected or voltage
protection is blocked. This can be performed by operation.
Before the device is energized for the first time, the device should be in the final oper-
ating environment for at least 2 hours to equalize the temperature, to minimize humid-
ity and avoid condensation. Connections are checked with the device at its final loca-
tion. The system must first be switched off and earthed.
Proceed as follows in order to check the system connections:
• The protective circuit breakers of the auxiliary power supply and of the measuring
voltage must be switched OFF.
• Check the continuity of all current and voltage transformer connections against the
system and connection diagrams:
– Is the earthing of the current transformers correct?
– Do the current transformer connections have the same polarity?
– Is the phase assignment of the current transformers correct?
– Is the earthing of the voltage transformers correct?
– Do the voltage transformer connections have the same, correct polarity?
– Is the phase assignment of the voltage transformers correct?
• Check the functions of all test switches that may be installed for the purposes of
secondary testing and isolation of the device. Of particular importance are test
switches in current transformer circuits. Be sure these switches short-circuit the
current transformers when they are in the test mode (open).
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