Panel Cooling Units / Precision Air Conditioning Units / Air-Cooled Chillers, Designing, Manufacturing and Distribution of Thermography
Selection of breaker and transformer
Refer to the following table for criteria for selecting capacity of breaker.
Single phase 200V
In case of using FA cooler from 400V power supply, refer to the following table for criteria for selecting capacity of transformer.
Note : √3=1.732
Here, following calculation method is also used for avoiding using transformer with higher capacity than required.
<Transformer capacity by rated current>
・In case of 3 - phase 200V,
Rated voltage (V) x rated current (MAX)(A) × √3...(1)
<Transformer capacity when taking usable capacity as 3 times (value from experience) against instantaneous overload >
Transformer capacity at the abovementioned starting current(VA) ÷ 3...(2)
(1) and (2) are compared and higher numerical value is selected.
Note) In case of this calculation, lowering in voltage at instantaneous 3 times overload is taken as about 5~10%. The abovementioned calculation may not be applicable as per usage condition.
Moreover, it is generally recommended to calculate transformer capacity from starting current and hence, numerical values calculated from abovementioned (1) and (2) do not guarantee its compliance.
Design, manufacturing and distribution of Heat Prevention Equipment and Thermography Equipment such as Panel Cooling Units, Precision Air Conditioning Units, Chillers, etc.