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After the decoration of our company, I found that the power supply cable of the building is 95 square meters, 160A empty, and we now need a single-phase electricity of about 210A current, the company's total power is 90kw demand, the electrician feels that the property can only be replaced empty, otherwise it can not be used, and the property does not agree to replace and suggests that each phase of electricity can be connected to 160A current, he has three-phase electricity as long as the three-phase balance is done, a total of 480A current, enough to use, no need to replace, please ask who they are right?
Answer: The 160A of the total circuit breaker switch refers to the rated current of each contact of the three-phase circuit breaker switch is 160A. Here it is a question of how much power the 160A circuit breaker can withstand.
According to the formula for calculating the power equal to the power divided by the voltage (P=UI), the power of 160A of the three-phase circuit breaker is 35000 watts = 35000/220, and if it is a three-phase load, its 160A (380 voltage) can carry 60800 watts.
However, the choice of the total circuit breaker switch is greater than 1.25 times of the full load current, which means that the 160A switch of the circuit breaker switch cannot operate at full load, because there will be some starting impulse current in actual operation, which must be taken into account. That is to say, your company's 90KW load needs to consider replacing a 250A main circuit breaker switch as a short-circuit and overload protection.
A circuit breaker switch with a rated current of 250A only costs more than 200 yuan, and the geometric size of its installation is exactly the same as that of 160A, but the contact capacity of the circuit breaker switch is larger. Replacing it with a qualified electrician only requires a small fee, and there is no need to dwell on this kind of problem.
And as a 95mm2 copper core power cable, it can fully meet the use of your company's 90KW load. This specification of power cable can have a current carrying capacity of 325A at an ambient temperature of 20°C, a current carrying capacity of 303A at 30°C, a current carrying capacity of 281A at 35°C, and a current carrying capacity of 257A at an ambient temperature of 40°C.
To put it simply, a 95mm2 copper core cable can drive a load of 168KW (kilowatts) without a single problem.