Hello, My transformer keeps tripping its internal breaker when my lights come on. This transformer worked well for about 4 years. Now whenever the lights come on they will stay on for a little while than the transformer will trip it's circuit breaker. I have checked the connection of the lighting wire to the transformer and it's in excellent condition. I have looked for a break in the wire where the wire isn't buried and can't see anything. If I turn the transformer on AND have my lights unplugged from the transformer it will not trip the internal circuit breaker. I do not want to dig up all my buried wire. Can this be an issue with the transformer going bad? It only does this under load and it's not immediate. Last night it happened after about 10 minutes. The night before, after about 2 hours. The night before that after about 30 minutes. Any idea on how to pinpoint if it is the transformer? TIA!