Regarding the issue of step-over tripping
Thread Content
The air compressor stopped operating due to the detachment of the inlet valve head. The issue is that the local thermal protection of the air compressor did not activate; nor did the molded case circuit breaker for the low-voltage supply in the high-pressure chamber (380V/630A) or the main low-voltage circuit breaker (380V/2500A) trip. Instead, it was the vacuum circuit breaker for the high-voltage side transformer’s supply (10KV/630A) that tripped, resulting in a power outage across the entire plant. Please help analyze the cause of this fault
The rated power of the air compressor is 250 KW
For the issue of step-over tripping, check the parameters for proper setting
This molded case circuit breaker is equipped only with overload protection; it has no overcurrent or undervoltage protection
Urgently need a solution, or a good answer. Thank you. . .
Does that mean the set value isn’t adjusted accurately?
High-voltage inverse-time tripping is normal; the low-voltage side has thermal protection, and since no heat has been accumulated yet, there’s no need for any adjustments. It’s sufficient to prevent such occurrences
The setting value of the long-time delay trip device for the motor circuit breaker is set too low.