381v, 221v is the relationship between line voltage and phase voltage. Electrical appliances use 381v for three-phase electricity and 221v for single-phase electricity. If the rated voltage of three-phase electrical appliances is 221v, a transformer is needed for transformation.

a three-phase voltage regulator is a four-layer three-terminal semiconductor device connected between a power supply and a load, and equipped with a corresponding trigger control circuit board, so that the voltage, current and power added to the load can be adjusted. It is mainly used to adjust the heating power of various electric heating devices, which can be adjusted manually, and can be matched with electric regulating instruments, intelligent regulating instruments, PLC and computer control systems to realize constant value or program control of heating temperature.

Extended information:

Precautions:

Please read this manual carefully before use, and connect the wires strictly as required.

installation method: wall-mounted vertical installation. Wiring should strictly ensure that the phase of the main circuit power supply is consistent with that of the control panel power supply, and the power supply is up and down. After overheating protection, if the device is to be operated again, it is necessary to remove the fault and then send it for operation.

it should be installed in a well-ventilated place where the working environment temperature is-11 ~+51℃, and it should be installed in a place where there is no corrosive or combustible gas, where wiring and maintenance are convenient, and where it is not exposed to direct sunlight or radiant heat sources.

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