Electric heating tube power and cable selection calculation
Calculation example:
There are 4 electric heating tubes, voltage 220V, power is 3000W two, 4000W one and 6000w respectively. If used together, how many square meters of total cable will it take? If you only use 10KW, how many square meters does the total cable cost?
I now try 1 3KW heating tube, use 4 square electricity bills, and find that the electricity bill is a little hot.
Reply:
220v3kw×2+4kw×1+6kw×1=16kw
16kw 16 flat
As long as it is a copper core wire, the cross-sectional area per square millimeter can safely pass the rated current of 4--5A; In the 220V single-phase circuit, every 1KW of power, its current is about 4.5A, in the 380V three-phase balanced circuit, every 1KW of power, its current is about 2A, the above values, can be calculated by the physical calculation formula The results are very close, so electricians in the work, in order not to remember those "cumbersome" calculation formulas, just remember these can be. Then according to this algorithm, it is known that the copper core wire per 1 square millimeter cross-sectional area, if used in a 220V single-phase circuit, can safely carry the current passed by a 1KW load, and if used in a three-phase balanced load (such as an electric motor) circuit, it can safely carry the current passed by a 2.5KW load.
At 220 volts, 1000 watts of current is equivalent to about 3.966 amps to 4 amps
At 380 volts, 1000 watts of current is equivalent to 1.998 amps to 2 amps
