UPS capacity selection

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Select the UPS capacity based on the following factors, characteristics, calculated load, shock current, peak current, overload capacity, and load abrupt change. The payload capacity is compensated by the following values.

1. About impulse current
Calculated capacity of UPS capable of withstanding peak current = payload capacity X impact current (maximum)/rated current of UPS, which is generally 5-10 times the effective capacity.
The load is put into the power supply and generates a considerable shock current, especially for computers and peripherals. During UPS power supply, in order to reduce the capacity of UPS, load is put into or selected for UPS mains power operation. When the current returns to the rated current value below, the power is converted to the rectifier and the inverter is supplied.


2. About peak current
UPS capable of withstanding peak current;
Capacity = payload capacity X peak current (maximum)/rated UPS current;
Peak capacity is generally 2 times of effective capacity;
For UPS with a peak coefficient of 2.5 or above, the peak current bearing capacity is 250%PA, which generally does not exceed the rated capacity of UPS and can be directly used without compensation.


3. Overload
The overload capacity of UPS is generally more than 1.1 times of the effective load. If the load overload is more than 1.1 times, UPS shall be protected.
4. Sudden change of load
Most UPS load changes are within the range of 0 "100%, and the output voltage fluctuation can be controlled within -10%I~A. Therefore, no compensation can be made for the payload capacity.
5. Generator-ups cooperation
In some places the UPS switches to a self-contained generator after a power outage. When the self-provided generator supplies power, it should be able to provide a large shock current when the UPS starts without affecting the operation of the generator.
1) select the rectifier device with a lower starting current UPS. For example, for a 12 pulse rectifier, the self-provided generator should have twice the capacity of the rectifier
2) select several sets of UPS for parallel connection and group delay start. It can be combined with slope start function to avoid excessive shock current caused by simultaneous start of all UPS.
3) select a UPS with rectified charger input power and controllable power, and make the rectifier charger input part of power, while the insufficient power is provided by the battery.
4) choose UPS with limited charging current function. When the generator is started up and running, limit the charging and set the charging current value to 0 Abe. That is, the charging can be stopped while the generator is running, thereby reducing the amount of power the UPS absorbs from the generator.

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New：2020-08-30  Click：10364  <<< Return

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