FCL/FCL-FX Series

A Frequency Converter (AKA Frequency Changer) is a device that converts the AC of one frequency to another frequency.  In addition, usually the Frequency Converter will also convert the voltage.

A Static Frequency Converter (SFC) does this electronically without any moving parts. Before the availability of SFCs,  the only way to change the frequency was by using an electro-mechanical Rotary Frequency Converter, in essence, a glorified motor generating set.

There are basically two types of Static Frequency Converters – those offering a variable adjustable output and those delivering a fixed output.

Variable Output Static Frequency Converters are primarily intended for applications with a need to replicate the various nominal utility mains voltages and civil frequencies deployed throughout the world –  making them ideal for use in testing centres, research laboratories, and testing on production lines.

Fixed Output Static Frequency Converters deliver a predetermined set output voltage and frequency and are usually intended to connect 60 Hertz powered equipment to a 50 Hertz supply, or 50 Hertz powered equipment to a 60 Hertz supply. Where required, they can also convert the supply voltage to a different voltage to match the requirement of the load.

As is frequently required for Aviation and Military applications,  variable and fixed output models are also available configured to deliver a 400 Hertz output.

Suitable for supporting most types of electrical and electronic equipment, Static Frequency Converters utilise solid-state Pulse Width Modulated (PWM) Inverter and Rectified technology, combined with galvanic isolation of the output to deliver a clean and regulated variable or fixed AC power supply. Typically models are fitted with additional protection features to ensure that the load is continually protected against harmful mains born high energy spikes and surges.

Static Frequency Converters have both maximum kVA (Apparent Power) ratings and kW (Real Power) ratings – the difference between the two being commonly referred to as the Power Factor.

In general, when sizing a Frequency Converter, neither the kW nor kVA rating of a Frequency Converter should be exceeded. Equipment nameplate ratings are often stated in kVA, which makes it difficult to know the kilo-watt ratings. If using equipment nameplate ratings for sizing, a user might configure a system, which appears to be correctly sized based on kVA ratings, but actually exceeds the Frequency Converters kW rating. By sizing the kVA rating of a load to be no greater than 60% of the kVA rating of the Converter, it minimizes the risk of exceeding the watt rating of the Converter. Therefore, unless you have a high certainty of the Watt ratings of the loads, the safest approach, and widely considered to be the ‘best practice’, is to keep the sum of the load nameplate ratings below 60% of the converters kVA rating.

Where the load type is inductive in nature, such as motors (fans, pumps, etc), solenoids, and relays, it is essential that high inrush current and short-time overload factors are fully considered. With motors (without a soft start facility) typically drawing on start-up current 5 to 7 times the stated rating of the motor it is recommended that a Frequency Converter is selected that is at least 3 times the stated rated capacity of the load.