Work Description---------------------UPS A1 battery charger failure alarm, after the supplier’s on-site inspection and confirmation, the batty charging control board needs to be replaced.Power resource A to IT devices will be running on by-pass. There will be potential risk of half power redundancy loss in case of utility power suspension. UPS B1 and STS mounted on each rack will be supporting comms room/closet during that time. After completing UPS A1 maintenance, switch back to UPS power supply and resume power supply.