news

An uninterruptible power supply or UPS is an electrical device that can provide supplementary emergency power to connected loads when the main power supply is interrupted. It is powered by a backup battery until the main power source is restored. The UPS is installed between the conventional power source and the load, and the provided power reaches the load through the UPS. During a power outage, the UPS will automatically and immediately detect the loss of the main power input power and switch the output power to come from the battery. This kind of backup battery is usually designed to supply power for a short period of time-until power is restored.
UPS is usually connected to critical components that cannot withstand power outages, such as data and network equipment. They are also used to ensure that the connected load (whether important or not) continues to operate optimally in the event of a power failure. These devices help prevent costly downtime, cumbersome restart cycles and data loss.
Although the name UPS is widely accepted as referring to the UPS system, the UPS is a component of the UPS system—albeit the main component. The whole system includes:
• Electronic devices that detect power loss and switch active output to draw from the battery • Batteries that provide backup power (whether lead-acid or other) • Battery charger electronic devices that charge the battery.
Shown here is an integrated uninterruptible power supply or UPS with batteries, charging electronics, charging control electronics, and output sockets.
The UPS system is provided by the manufacturer as an all-in-one (and turn-key) component; the UPS electronics and charger are integrated in one product, but the battery is sold separately; and completely independent UPS, battery and battery charger products. Fully integrated all-in-one components are most common in IT environments. UPS systems with UPS and battery-free charger electronics are most common in industrial environments such as factory floors. The third and least popular configuration is based on a separately provided UPS, battery, and battery charger.
UPS is also classified according to the type of power source (DC or AC) with which they are compatible. All AC UPSs back up AC loads… and because the backup battery is a DC power source, this type of UPS can also back up DC loads. In contrast, a DC UPS can only back up DC-powered components.
As mentioned earlier, the UPS system can be used to add DC and AC mains power. It is important to use the correct UPS for the type of power supply in each application. Connecting AC power to a DC UPS will damage components… and DC power is not effective for AC UPS. In addition, each UPS system has a rated power in watts—the maximum power that the UPS can provide. In order to provide adequate protection for the connected loads, the total power demand of all connected loads must not exceed the capacity of the UPS. To adjust the size of the UPS correctly, calculate and summarize the individual power ratings of all components that require backup power. It is recommended that the engineer specify a UPS whose rated power is at least 20% higher than the calculated total power requirement. Other design considerations include…
Use time: The UPS system is designed to provide supplementary power and cannot be used for a long time. The UPS battery rating is in ampere hours (Ah), specifying the capacity and duration of the battery… For example, a 20 Ah battery can provide any current from 1 A for 20 hours to 20 A for one hour. Always consider the battery duration when specifying a UPS system.
Maintenance personnel should understand that the main power supply should be restored as soon as possible, and the UPS battery cannot be completely discharged. Otherwise, the backup battery may prove to be insufficient… and leave the critical load without any power at all. Minimizing the use time of the backup battery can also extend the life of the battery.
Compatibility: For optimal operation, the power supply, UPS, and connected load must all be compatible. In addition, the voltage and current ratings of all three must match. This compatibility requirement also applies to all complementary wires and intermediate components in the system (such as circuit breakers and fuses). The sub-components (especially UPS control electronics and chargers) in the UPS system manufactured by the system integrator or OEM must also be compatible. Also check whether the wiring of any such field integration design is correct…including terminal connections and considering polarity.
Of course, the compatibility of the sub-components in the fully integrated UPS system is guaranteed because this is tested by the supplier during manufacturing and quality control.
Operating environment: UPS can be found in a variety of typical to extremely challenging environments. The UPS manufacturer always specifies the maximum and minimum operating temperature for the normal operation of the UPS system. Use outside of this specified range can cause problems-including system failure and battery damage. The manufacturer (with certification, approval, and rating) also specifies that the UPS can withstand and operate in environments with various humidity, pressure, airflow, altitude, and particle levels.
Installation and operation: Various manufacturer-specific installation and operation rules need to be followed to ensure the normal operation of the UPS system throughout its design life. There are also general guidelines that apply to all UPS.
• Installation can only be carried out by qualified personnel • All power must be turned off when installing or disconnecting • To avoid electric shock and other hazards, do not disassemble or modify the UPS • Check all connections to ensure correct completion • Installation and operation personnel are installing and operating Read the UPS installation manual and product guide beforehand.