I have 10 year old central A/C (Lennox), but have lived in house only 2 summers. Last summer A/C ran fine. Twice this summer within the past 10 days I found the A/C circuit breaker in the service panel had tripped. So things were OK for 10 days after first tripping of breaker was reset. Service tech found no problems in pre-season check-up. Any guess as to whether this behavior indicates compressor problem vs. circuit breaker problem?