We installed 9 well lights within a sidewalk 2 weeks ago. Since then we have gone through 12 bulbs. They are the PAR 36 style bulbs that have the stacon connectors. The bulbs keep blowing(commonly referred to as smoked). The volts at the fixtures are reading 11.3- 12.0v. Only 3 fixtures per run on 10 wire. Anybody have experience with this? I am stumped and the manufacturer has yet to come up with something.