Full load operating time
UPS continuous operation time from a fully charged battery when connected to a load with a power equal to the UPS output power (maximum or effective, depending on the type of load, see the relevant paragraphs for details). For a UPS designed to work with a home or office PC, a time of about 10-15 minutes is considered sufficient, this is enough to save data and complete work. To power servers, it is worth using devices with an operating time
of 20 minutes or more.
Half load operating time
UPS continuous operation time from a fully charged battery when connected to a load with a power equal to half the output power of the UPS (maximum or effective, depending on the type of load, see below for details). The operating time with such a load is much longer than for a full load, and even in the simplest models it can reach 20-30 minutes.
Switching to battery
The time required to transfer the load from mains power to battery power. In standby and
interactive UPSs (see Type), a short-term power failure occurs at this moment — accordingly, the shorter the time to switch to the battery, the more uniform the power supply is provided by the source during a power failure. Ideally, the switching time for the traditional 50 Hz AC frequency should be less than 5 ms (a quarter of one cycle of the sine wave). With inverter UPSs, the transfer time is, by definition, zero.
Input voltage range
In this case, the input voltage range is implied, in which the UPS is able to supply a stable voltage to the load only due to its own regulators, without switching to the battery. For redundant UPSs (see "Type") this range is quite small, approximately 190 to 260 V; for interactive and especially inverter ones, it is much wider. Some UPS models allow you to manually set the input voltage range.
Input frequency
The operating frequency of the alternating current supplied to the input of the UPS — or more precisely, the frequency range of this current in which the device can supply the required power to the load due to its own regulators, without using a battery. When this range is exceeded, the UPS switches to battery mode. The smallest input voltage range is reserved for standby UPSs (see "Type"), the largest for inverter UPSs.
Efficiency
Efficiency (coefficient of performance) in the case of a UPS is the ratio of its output power to the power consumed from the network. This is one of the main parameters that determine the overall efficiency of the device: the higher the efficiency, the less energy the UPS wastes (due to heating parts, electromagnetic radiation, etc.). In modern models, the efficiency value can reach 99%.
Output frequency
The frequency (frequency range) of the AC voltage output by the UPS. For computer technology, the frequency range of 47-53 Hz is considered normal, although the smaller the deviation from the 50 Hz standard, the better. On the other hand, in some UPS models, this frequency can be automatically synchronized with the frequency of the mains — so the power supplied to the load will not differ regardless of whether the load is powered by the mains or from the battery. In this case, a wider frequency range, on the contrary, is more desirable.
Full charge time
The time it takes to fully charge the UPS battery. Note that in this case, this time is calculated according to special rules: not from 0 to 100% of the charge, but from a state in which it is impossible to maintain half the load, up to 90% of the charge. Of course, a full charge will take a little longer. However, this data is closer to practice than the “from 0 to 100%” calculation: the inability to work at half load makes the UPS practically useless, and this condition can be taken as zero, and 90% of the battery is already able to provide a good guarantee in case of a power failure.
Fuse
Fuses are used to protect the UPS from a critical increase in current strength: at the right time, they open the circuit, preventing unpleasant consequences. Today, these types of fuses are used.
— Melting. At a critical current strength, the conductive element in such a fuse melts and opens the circuit. The fusible protection is disposable, after operation such a fuse must be replaced.
— Automatic. Such a fuse has a sensor that monitors the current strength and opens the contacts at the right time. Its main difference from fusible is reusability: after operation, the circuit can be closed again with literally one press of the button on the fuse.
