UPS Corrective and Preventive Maintenance
UPS Corrective and Preventive Periodical Maintenance
Maintenance of the UPS consists of preventive and corrective maintenance. Preventive maintenance consists of a scheduled list of activities. Performing these activities keeps the UPS in good working order and helps to prevent failures.
Corrective maintenance is performed as a result of a failure. Corrective maintenance fixes the problem and gets the unit working again.
Although Uninterruptible Power Supplies are designed and manufactured to operate continuously on a 24/7 basis, they may fail due to irregularities in the mains voltage, bad environmental conditions (humidity, temperature, dust, etc). They also may fail due to external factors such as adverse working conditions, aging of the product and sub-components, improper use, and long working under excessive load. This situation may put business owners who want to use their critical loads in a difficult situation without interruption. At the same time, systems that are not maintained on time and by the expert technical personnel may be out of service, as well as will harm to environment and alive (fire, explosion etc.) Uninterruptible Power Supplies
In order to prevent these undesirable situations, it is very important that critical devices are kept under control and their periodic maintenance is done on time, with trained technical personnel and original spare parts approved by the manufacturer. Statistics show that periodic maintenance significantly reduces the failure rate.
A standard maintenance procedure cannot be developed for all types of UPS units. Apart from the general requirements, the manufacturer's instructions for each device should also be considered during maintenance.
Safety
Corrective and Preventive maintenance should only be carried out by expert technical personnel. Always be aware of the DANGER, as voltages within the UPS modules and associated switchgear are lethal.
It is necessary to open the circuit breaker in the distribution panel feeding the UPS and the UPS bypass circuit breaker, plus opening the direct current (dc) link connection to the battery, before all dangerous voltages within the UPS are eliminated. Capacitors may need to be discharged of their stored energy. . The UPS must not be intervened before all dangerous voltages inside the UPS are isolated and the energy in the capacitors is discharged.
Take all precautions when operating UPS equipment to prevent serious injury or death.
Preventive maintenance
Periodic maintenance is required to maintain efficiency and life of UPS equipment and its hardware. They require planned maintenance as they are operated under continuous high voltage. Preventive maintenance requires the UPS system to be shut down. The following procedure should be followed during maintenance
1. Records
Preventive maintenance is systematic maintenance. The objective is to minimize equipment operating problems and prevent failures by making minor or necessary repairs before major operating difficulties occur. The general condition of the equipment needs to be evaluated periodically, and records need to be maintained for comparison at subsequent inspections. Recorded information is more reliable than a maintenance technician’s memory.
Records should be short, but fully describe equipment conditions and maintenance.
In these records, the following points must be specified
- All descriptive information of the equipment (Model, Serial Number, Power, Voltage, Used Battery etc.)
- List of replaced parts and their costs
- Inspection checklist
- Periodic maintenance program
- Maintenance inspection and repair records
2. Planning
Scheduling of UPS and Battery maintenance is normally based on the manufacturer's recommendations. Because a UPS system is vital for the operation of critical loads, it may be advisable to perform more control than the manufacturer recommends. Some items on the UPS can be inspected daily or weekly.
This inspection can be done by operating personnel, but data should be recorded for use as needed. Battery maintenance should be done by maintenance personnel.
These inspection records should be kept for use in regular periodic controls. Planning regular periodic controls in advance will make it easier to stop the business on time.
3. Periodic System Status Checks
Continuous monitoring of the operating status of any electronic equipment greatly increases the likelihood of preventing that equipment malfunction. Daily monitoring can be done as well as weekly checks.
In these controls, Mimic Diagrams, Alarms, input, output, battery and bypass voltages and currents must be checked and recorded. In addition, it should be seen that the fans are running, sufficient ventilation is provided, all doors, drawers and covers should be fixed, and unusual noises and odors should be checked.
4. Planned Periodic Maintenance
Preventive periodic maintenance should be carried out at least twice a year, depending on the manufacturer's instructions and the critical load status of the enterprise.
In these maintenances, previous condition control records are examined and system maintenance is done including but not limited to the following and the results are recorded.
• Examination of device error logs
• Review of maintenance logs
• General cleaning of the device, cleaning the fans
• Checking the environment, temperature, dust, humidity, room vents, etc.
• Checking mechanical and electrical connections
• Control of electronic cards
• Check every battery voltage
• Testing battery performance
• Functional control of the UPS (Static / Manual ByPass Mode and Battery Mode transitions)
• Checking device calibration values and if needed, renew
• Checking device loads
• Fix out found malfunctions and errors
• Replacement of end-of-life or near-completion parts
• Checking the batteries and replacing the end-of-life / near-end batteries
• Controlling communication units
• Installing new software, if available