GRAPH ANALYSIS

The instruments present results not only in digital, but also in graphical form. The graphical data include important information on the condition of a high-voltage circuit breaker or transformer under examination.

Graph analysis performed by the SKB EP specialists is an evaluation of condition of:

1. High-voltage circuit breaker:

• switch on and switch off buffer condition;
• availability of end plays between drives, poles and rods;
• drive operation delay related to condition of drive springs or electromagnets;
• rubbing of moving parts;
• contact closure/opening velocity;
• other defects emerging after comparison of typical graphs of operable circuit breakers.

2. Transformer elements:

• break of current-limiting resistors;
• contactor switchover time delay;
• availability of undertightened fixed contacts;
• contactor actuation procedure check during switchover;
• right connection of the transformer regulating winding to OLTC contacts.

According to the data analysis, the major failures may be determined, which shall be immediately repaired.

Please, be aware that the consolation on the following issues is provided for free:

• Occurrence of error during software installation;
• Occurrence of error, when the instrument is connected to the computer;
• Correctness of the instrument connection to the circuit breaker;
• The obtained data are random, unreasonable or strange (i.e. when the report is drawn up, the indicators have a 0.0000000000 value, that is related to incorrect connection of cables to the instrument).