Chi
LO relay is tripped by LOT.
I would look to see why LOT tripped LO.
LOT may also be use as a redundancy for your motor starter and the overload. An example would be if your 3 phase contactor single phased. LOT would see that the car is trying to run longer then it would take to go from the bottom to the top floor. LOT would time out and picks LO. LO is self holding. When the maintenance man pulls the main line he is dropping out LO.
I suggest you start with you contacts on the motor starter. See if they are pitted or hanging up.
