Transformer blown primary fuse detection using secondary
Transformer blown primary fuse detection using secondary
(OP)
We have a problem detecting blown primary fuses on a main substation transformer. The primary has fuses only. The secondary side of the transformer has a circuit breaker with a GE Multilin 760 relay. We want an inexpensive method to look for unbalanced phase or phase loss due to blown fuses on the primary by utilizing the CT's and PT's on the secondary. At this point, we want to alarm as soon as fuses are blown. This would allow us to switch to another transformer and replace the blown fuses on the first unit. We want something inexpensive and to use existing equipment if possible.






RE: Transformer blown primary fuse detection using secondary
RE: Transformer blown primary fuse detection using secondary
Negative phase sequence voltage is good, but not 100% reliable. If there is load on the system, it is probably best to use negative phase sequence overcurrent (ANSI 46), incombination with under/over voltage (27/59).
Also see thread238-101093
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