Greetings All,
we have loop transformers feeding facilities inside our camp ... We have 6 transformers 13.8kv/480v ... The loop is fed from two sources (Breakers) and in the middle of the loop there is a normally open point dividing the loop into two sections. To make it easier for you let's consider it like this: section 1 The power is coming from the breaker to SF6 switch then to the transformers and the same thing for section 2. All the transformers are delta-Y except one transformer is Y-Y. This is the first transformer in section 1 located after SF6 switch.
The problem:
Always Section 1 of the loop is interrupted with a relay target (earth fault) on the SF6 switch and after deeply investigations we have nothing. The interruption happened three times within 4 months and the results are same.
My Question:
What do you think the problem? Is there something happened before with you for a Y-Y transformer.? Is there a specific test you recommend us to do?
we have loop transformers feeding facilities inside our camp ... We have 6 transformers 13.8kv/480v ... The loop is fed from two sources (Breakers) and in the middle of the loop there is a normally open point dividing the loop into two sections. To make it easier for you let's consider it like this: section 1 The power is coming from the breaker to SF6 switch then to the transformers and the same thing for section 2. All the transformers are delta-Y except one transformer is Y-Y. This is the first transformer in section 1 located after SF6 switch.
The problem:
Always Section 1 of the loop is interrupted with a relay target (earth fault) on the SF6 switch and after deeply investigations we have nothing. The interruption happened three times within 4 months and the results are same.
My Question:
What do you think the problem? Is there something happened before with you for a Y-Y transformer.? Is there a specific test you recommend us to do?
