This alarm indicates that the current transformer direction is reversed.

Please swap the two secondary-side CT wires, for example by exchanging S1 and S2.

You can also use a multimeter or power quality analyzer to check the phase angle. Under normal conditions, the angle between the A-phase current and voltage should be within ±5°.

The choice depends on the installation environment and application requirements.

Wall-mounted type:

Suitable for independent or small-capacity applications, such as residential buildings, commercial spaces, or compact electrical rooms.

Rack-mounted type:

Suitable for industrial cabinets and larger systems. Multiple modules can be combined for higher capacity and flexible expansion.

The 3rd harmonic is a zero-sequence component, which accumulates in the neutral line and may cause overheating, nuisance tripping, or equipment instability.

Our APF is equipped with standard neutral-line filtering capability, with performance up to three times stronger than conventional models. It is especially effective for solving neutral-line overheating and tripping problems in LED displays, data rooms, computer rooms, and similar applications.

Our APF supports selective filtering from the 2nd to the 51st harmonic order. A single module can filter up to 20 different harmonic orders simultaneously.

For equipment such as medium-frequency furnaces, customized high-frequency filtering up to the 70th harmonic order is also available.

The SVG capacity can be calculated by actual measurement or estimation.

Measurement method:

Use a power quality analyzer to record the maximum reactive power demand Q kvar over 24 hours.

Recommended SVG capacity: ≥ 1.2 × Q

Estimation method:

Transformer capacity kVA × 30%

For example, a 1000 kVA transformer is generally recommended to use a 300 kvar SVG.

A traditional capacitor bank usually has a response time of 20–40 ms, while our SVG has a full response time of less than 5 ms, including sampling, calculation, and output.

This makes SVG especially suitable for impact loads such as welding machines, cranes, and other rapidly changing loads, helping to avoid over-compensation or under-compensation.

Our SVG/APF products adopt an N+1 redundancy design. If one module fails, it will automatically exit operation, while the remaining modules continue working normally.

The hot-swappable structure allows module replacement without power shutdown, and the maintenance time is typically less than 5 minutes.

SVG is mainly used to solve reactive power problems, such as improving power factor and stabilizing voltage. APF is specifically designed to filter harmonic currents.

If the on-site power factor is low and the harmonic distortion rate is higher than 5%, we recommend using SVG and APF together.

If you only need to improve the power factor, SVG is the right choice.

If precision equipment frequently malfunctions or trips, APF should be prioritized.