Three-phase power connection method for stainless steel heating tube

The three-phase power connection methods for electric heating tubes and stainless steel electric heating tubes mainly include star and delta connections. The choice is determined by the rated phase voltage of the heating tube at the time of manufacture.

For three-phase voltage in a star connection, each phase of the power supply or load is connected to a single point, with the other ends of each connected point serving as the three phases of the three-phase voltage. In a star connection, the midpoint (called the neutral point) can be connected as the neutral line, creating a three-phase four-wire system. Alternatively, it can be omitted, creating a three-phase three-wire system. Of course, regardless of whether a neutral line is present, a ground line can be added, creating a three-phase five-wire system or a three-phase four-wire system.

For three-phase voltage in a delta connection, each phase of the power supply or load is connected end to end, and each connected point is connected as the three phases of the three-phase voltage. A delta connection has no neutral point and cannot be connected to a neutral line, resulting in a three-phase three-wire system. Adding a ground line converts the system to a three-phase four-wire system.

In a star-connected three-phase system, the line voltage is equal to the square root of three times the phase voltage, while the line current is equal to the phase current. When the three-phase load is balanced, no current flows even if the neutral line is connected. When the three-phase load is unbalanced, the neutral line should be connected; otherwise, the loads on each phase will be divided into unequal voltages. In a delta-connected three-phase system, the line voltage is equal to the phase voltage, while the line current is equal to the square root of three times the phase current.