Reefer Intermittent Total Electric Power Loss

Hoping someone that has experience with this unit can help.

Carrier x2 2100A in Start/Stop initially starts just fine, reaches set temp, and shuts off as programmed. For the next hour or so it runs Start/Stop fine. But after about an hour on another restart to begin cooling again, tries to start the engine and has TOTAL power loss. Complete blank out on control panel and electric power gone before it can even log an alarm. A moment later since the physical on switch is in the on position it begins the control panel start up as if I just flipped the on switch. Engine tries to start and unit completely loses power again, repeats until the battery is completely drained. The trailer gets benched or used as a dry van for the rest of the day since it won’t work.

Service gets called for an after hours repair but works fine for them in the allotted time they inspect. ‘We don’t see any problems.’ I have it on video and have witnesses but it won’t do it for them. So I’m tearing my hair out.

Has anyone had experience with their reefer behaving like this and where should I start looking since I guess I gotta figure this out.

Thanks and God Bless