S230B can simultaneously measure three-phase AC voltage, current, voltage between phases, phase between currents, phase between voltage and current, frequency, phase sequence, active power, reactive power, apparent power, and without the open circuit of the circuit under test. Power factor, current vector sum, discriminate transformer wiring group, inductive, capacitive circuit, test secondary circuit and busbar protection system, read the phase relationship between differential protection CT, check the wiring of the meter correctly Whether or not to repair line equipment, etc. Special toolbox for durability.