I have various lights on each side of the house using two transformers. One transformer keeps turning off soon after it turns on. The toggle switch clicks off. These are 150 watt transformers. I added up the watts of the lights on that transformer and it's at 130 watts. I have three runs of 10/2 wire with the longest run at about 200ft. Any ideas what to check out? Am I maxing out the transformer?
Most likely yes. The product docs specify a power factor of .7. If they total 130, you'd be well over the rated capacity at 185+.