This post is also available in: English (อังกฤษ) Preventive Maintenance Battery paramiter and capacity test Battery charger preventive maintenance UPS preventive maintenance and repairing High power DC Rectifier preventive maintenance Engineering and Installation Design and supply DC rectifier power supply Modify control system and renovate for old rectifier Design and install high current (Upto 100,000 Adc) Aluminium for large DC Rectifier power supply