Checking The Voltage Circuits - Siemens SIPROTEC 7VU681 User Manual

• The limit values specified in the Technical Specifications (section 4.1) must not be exceeded, also not during
testing and during commissioning.
DANGER!
Hazardous voltages during interruptions in secondary circuits of current transformers.
Nonobservance of the following measure will result in fatality, severe personal injury or substantial material
damage.
Short-circuit the current transformer secondary circuits before current connections to the device are opened.
If test switches are installed that automatically short-circuit the current transformer secondary circuits it is
sufficient to place them into the "Test" position provided the short-circuit functions has been previously tested.
All secondary test equipment should be removed and the measurement voltages connected. The operational
preparations must be completed.
Preparation
Please perform the following preparatory commissioning steps:
• Install an EMERGENCY OFF button for direct trip of the excitation
• Check the parameter setting, if need temporarily setting in commissioning, change to temporarily setting.
• Check the binary input and measurement input.
• The mode of power support transfer is same with test scheme, according to the requirement of site.
Test
Please perform the following preparatory commissioning steps:
• Manual/remote Open CB. Check device Binary output, LEDs is same with the setting.
• Check function, site/remote start power support transfer function, check device doing is same with the
setting.
• According the setting, cut off power of busbar ( fault start mode, undervoltage mode...etc ), check device
doing is same with the setting.
3.3.6

Checking the Voltage Circuits

General
The voltage circuits of the machine are checked to ensure the correct cabling, polarity, phase sequence,
transformer ratio etc. of the voltage transformers - not to check individual protection functions of the device.
Test Instruction
The checks of all voltage transformer circuits (protection, measuring, metering etc.) are carried out with about
30 % of the rated transformer voltage.
The measuring circuit supervision of the rotor earth fault protection (see below) can be checked when testing
the voltage circuits, or after the synchronization.
SIPROTEC, 7VU681, User Manual
C53000-G1176-C368-1, Release Date 07.2012
Mounting And Commissioning
3.3 Commissioning
91