Types of UPS
Equipment is powered by the grid directly through a bypass line. In the event of a power failure it is powered by AC current generated by an inverter run by a battery in the UPS.
1. When commercial power is normal, the UPS does nothing and the load is handled directly by the grid. This type does not improve grid power with respect to noise and surge suppression.
2. Provides the least protection as a certain conversion time is needed.
3. Simple in structure, compact in size, light in weight, easy to control and not very expensive.
The on-line UPS supplies power to the load by output from the inverter and uses the bypass path only in a case where the UPS itself fails, is overloaded, or overheats.
1. Output power to the load is of the best quality as it is processed by the UPS.
2. No conversion time is required.
3. Complex in structure and expensive.
4. Gives the highest protection and has excellent noise filtering and surge suppression capacity.
The line-interactive UPS supplies power to the load through the bypass path with output from the inverter when grid power is normal. The inverter acts as a charger at this time. In the event of a black out, the inverter converts DC current from the battery to AC for output to the load.
1. The bi-directional conversion design reduces the time required for charging the UPS battery.
2. Requires a certain conversion time.
3. The complex control mechanism makes it more expensive.
4. Has protection capacity between that of the on-line and off-line UPSs. It is less effective in noise filtering and surge suppression.
Common battery problems
2. Appraise your needs for power quality.
3. Learn the required UPS capacity and appraise the total capacity required for future expansion.
4. Select a market proven brand and supplier.
5. Purchase an appropriate UPS that is suitable for your requirements.