Changes of Molded case circuit breaker, Earth leakage circuit breaker
which generation does your molded case circuit breaker belong to?
which generation does your earth leakage circuit breaker belong to?
Recommendation of preventive maintenance
Renewing equipment at the appropriate time prevents serious accidents and their spread
Internal equipment used in receiving/distribution facilities has a limited life expectancy.
Preventive maintenance is important
- Time based maintenance: planned replacement and repair before the failure rate exceeds its allowable value.
- Condition based maintenance: planned replacement and repair when the failure rate exceeds its allowable at periodic diagnosis.
(a) Early failure period: After a start of operation, there are possibilities of weaknesses that take time to adopt to an external environment and of failures in manufacture.
(b) Random failure period: The failure rate constantly continues without any relation to elapsed time.
(c) Wear-out failure period: The failure rate keeps increasing due to equipment deterioration or wear of components. This is the period witch you have to consider an overhaul or a upgrade of equipment for maintaining the functionality as a facility.
Recommended upgrade periods of equipment
the japan electrical manufacturers' association (jema) suggests the following recommended upgrade periods by type of equipment used for high-voltage facilities based on reports from the institute of electrical engineers of japan and questionnaires to business operators by the ministry of land, infrastructure, transport and tourism.
|Product||Recommended upgrade period (after start of use)|
|Circuit breaker||15 years or specified switching times|