UPS power supply and load matching - Database & Sql Blog Articles

Some UPSs use watts (W) or kilowatts (kw) to indicate their output power, such as 500W, 1kw, etc.; some UPSs use volt-amperes (VA) or kilovolt-amperes (kVA) to indicate their output power, such as 3000VA , 5kVA, etc. The general conversion relationship between VA and W is: the watt is 0.8 times the volt-amperes, such as 3kVA = 2.4kw. UPS is used for line load power supply, and each UPS has a specific output power capability. For example, a 3kVA UPS has a maximum output power of 3kVA or 2.4kw. At this time, the total power consumption of the equipment connected to the UPS cannot exceed 2.4 kW. Usually the equipment is marked with power consumption (or rated power). At this time, the rated power of all equipment connected to the UPS should not exceed the output power of the UPS. This method is usually called UPS output power and load consumption. Matching of electric power. However, the starting power of some devices is 3-5 times of the rated power (for example, if the rated power of the printer is 200W, it should be converted by 5×200W=1000W when calculating the load matching). In addition to printers and other computer peripherals, the starting power is usually slightly greater than the rated power, so it is best to match the load with 80% of the UPS output power when considering matching.

Before the standard UPS is not equipped with an external battery, in the case that its output power is fully matched with the load power consumption (ie full load), it can be powered for about 6-10 minutes from the interruption of the mains supply (specific value each The UPS specification of the model is documented). If the load power consumption is only half of the UPS output power (usually called half load or 50% load rate, such as 1000W UPS connected to 500W load), it can supply 12-25 minutes, UPS power supply under different load levels. The time can be calculated by referring to the doubling of the load halving time. Precautions for use Correct use of the ups power supply not only reduces the chance of UPS failure, but also effectively extends its service life.

Usually should pay attention to the following points:

(1) When using UPS power supply, the relevant provisions of the manufacturer's product manual should be strictly observed to ensure that the live line and neutral line of the UPS connected to the mains meet the requirements.

(2) The main purpose of equipped with UPS is to prevent the computer from losing information and destroying the hard disk due to sudden power failure, but some devices are not afraid of sudden power failure (such as printers) when working. In order to save the energy of the UPS, the printer can consider directly accessing the mains without having to go through the UPS. In the case of a network system, consider that the UPS only supplies power to the host (or server) and its related parts. This ensures that the UPS can use both the most important equipment and save investment.

(3) Do not use the UPS with overload. The maximum load of the UPS power supply should be 80% of its nominal load (such as 1000w UPS, 80% load rate or 800W to match the load: 1000VA UPS converted to 800W after 80% and then 80% load rate 640W to match the load). If overloaded, in the inverter state, the breakdown of the inverter transistor is often caused. In addition, when using the UPS, it is strictly forbidden to connect an inductive load such as a fluorescent lamp, but only a pure electric or a small capacitive load.

(4) When switching on and off, you should pay attention to the sequence of switching machines: first turn on the UPS when starting up, later (preferably lag 1-2 minutes, let the UPS fully enter the working state) and then turn on the load power switch, and the load power switch To turn on one by one: the order is the opposite when shutting down, first turn off the load power switch one by one, then turn off the UPS. The UPS should be turned on for a long time, and the load such as the computer should be turned on every time. After use, just turn off the power switch of the computer and other loads.

(5) Do not turn the UPS power on and off frequently.

Generally, after turning off the UPS power supply, wait at least 6 seconds before turning on the UPS power. Otherwise, the UPS power supply may be in the state of “startup failure”, that is, the UPS power supply is in the state of neither the mains output nor the inverter output. Not normal.

(6) The power in the battery inside the UPS may be exhausted or nearly exhausted for some reason. In order to compensate for battery energy and improve battery life, the UPS should perform a timely, long-term continuous charging (usually no less than 48 hours, with or without load) to avoid failure due to battery failure. UPS newly purchased or stored for a long time should be charged for 12 hours before use. Long-term storage of unused UPS, charging for 12 hours every 3 months, if in high temperature, charging once every 2 months. The UPS will be used without charging, which will damage the battery.