Last week, a friend mentioned that it was his first time conducting a circuit breaker test independently, and he got the operation sequence wrong, causing the equipment to trip into protection mode as soon as it was powered on. Actually, such issues are quite common, and the root cause is often failure to follow the correct procedure. Below, I have collated the standard operating steps for a three-phase current booster for your reference.

1. Preparations before power-on

Many people skip this step, but it is often the root cause of accidents. Before connecting the power, be sure to disconnect the "power control" switch and simultaneously turn all three knobs for A-phase adjustment, B-phase adjustment, and C-phase adjustment counterclockwise to zero. The purpose of this is to prevent the equipment from starting with load at the moment of power-on, which could cause a shock to the tested object.

II. Wiring

Connect the three-phase four-wire power supply to terminals A, B, C, and N, and then use a dedicated test lead to connect the phase current output terminals A, B, and C to the device under test. After wiring is completed, be sure to double-check: first, to confirm that the wiring is correct, and second, to check whether the connector contacts are reliable. Special attention - the current output terminals must form a complete circuit, otherwise the device will not have current output.

III. Upflow Operation

Turn on the "Power Control" switch, press the "Start" button, and then slowly adjust the corresponding phase knob clockwise to increase the current to the desired value for the test. If simultaneous adjustment of all three phases is required, adjust the three-phase tuning knob first. After the test is completed, press "Stop" and confirm that the current of each phase returns to zero before disconnecting the wiring.

IV. Phase loss/imbalance test

Simply adjust a certain phase knob back to zero position, or directly disconnect the phase output line, to simulate a phase loss condition. The same principle applies to three-phase imbalance testing; adjust the three knobs to different current values respectively.

V. Several common pitfalls to avoid

Under no circumstances should any wiring be plugged in or pulled out when the power is on

If the device shows no display after being turned on, first check the power cord, and do not press the start button repeatedly

When only 220V power supply is available on site, ABC input can be short-circuited to the live wire, with N connected to the neutral wire, and other operations remain unchanged

Wait for 10 minutes after each experiment before conducting the next one to allow the equipment to fully dissipate heat

Following this process will significantly reduce the probability of making mistakes.