What is screened flex (SY) cable used for?

Screened flex (SY) cable is used for flexible wiring in applications where protection against electrical interference is required, such as control panels, machinery, and automation systems.

What does LSF mean for screened flex cables?

LSF stands for low smoke and fume, meaning the cable emits less smoke and fewer toxic gases in the event of a fire.

Can screened flex cable be used for fixed wiring?

Screened flex cable is primarily intended for flexible connections and should only be used in fixed installations if correctly protected and compliant with regulations.

How do I choose the correct size screened flex cable?

Cable size depends on electrical load, application type, and cable length. Technical guidance or professional advice should be followed.

Screened Flex (SY) LSF Cables

Q: What does the screen do in a screened flex cable?

The braided screen reduces electromagnetic interference from nearby electrical equipment, helping maintain stable signal transmission.

Screened Flex (SY) LSF Cables for Protected Flexible Wiring

Browse our range of screened flex (SY) LSF cables designed for flexible electrical wiring where additional protection against interference is required. These cables feature a braided screen that helps reduce electromagnetic interference while maintaining flexibility for moving or vibrating equipment. Manufactured with low smoke and fume insulation, screened flex LSF cables are suitable for use in commercial, industrial, and controlled domestic environments. Available in multiple core sizes and sold cut per metre, this range allows you to select the correct specification for control systems, machinery, and specialist electrical applications.

Frequently Asked Questions

Screened flex, often referred to as SY cable, is used in applications where flexible wiring is required along with protection from electrical interference. It is commonly installed in control panels, machinery, automation systems, and equipment where signal integrity is important. The braided screen helps reduce electromagnetic interference while allowing the cable to move or bend during operation.

The screen is a braided metallic layer that surrounds the inner cores of the cable. Its main purpose is to reduce the effects of electromagnetic interference from nearby electrical equipment. This helps maintain stable signal transmission and reduces the risk of disruption, especially in environments with motors, drives, or other sources of electrical noise.

LSF stands for low smoke and fume. Screened flex LSF cables are designed to emit less smoke and fewer harmful gases in the event of a fire. This improves safety by maintaining visibility and reducing toxic exposure, which is especially important in enclosed or occupied spaces.

Screened flex cable is primarily intended for flexible connections rather than permanent fixed wiring inside walls or ceilings. It is best suited for equipment connections and control applications. If used in a fixed installation, it must be installed in a way that provides suitable protection and complies with local wiring regulations.

The correct cable size depends on the electrical load, the number of cores required, and the length of the cable run. Smaller sizes are typically used for control signals and light-duty applications, while larger sizes are required for higher current loads. Always refer to technical specifications or consult a qualified electrician when selecting a cable size.

Tips & Guides

When to use screened flex cable instead of standard flex

Screened flex cable is the better choice when electrical interference could affect performance, such as in control systems, machinery, or installations near motors and drives. The braided screen helps reduce noise and improves reliability, making it suitable for more demanding environments than standard flexible cable.

Understanding SY cable construction and benefits

SY cable is constructed with multiple insulated cores, an overall braided screen, and a durable outer sheath. This design provides flexibility, mechanical protection, and shielding from interference. The LSF outer sheath adds an extra safety benefit by reducing smoke and toxic emissions in the event of a fire.

Choosing the right screened flex cable for control systems

When selecting screened flex cable for control applications, consider the number of cores needed, the operating voltage, and the level of interference present in the environment. Proper grounding of the screen is also important to ensure effective shielding and reliable performance.

Installing screened flex cables correctly

Correct installation is essential for screened flex cables to perform as intended. The screen should be properly terminated and grounded according to best practice. The cable should also be supported and protected from excessive strain, bending, or mechanical damage during use.

Buying screened flex LSF cable cut per metre

Buying screened flex cable cut per metre allows you to order the exact length required for your project. This reduces waste and ensures better cost control. When measuring, allow extra length for termination and routing, and confirm the selected size meets the requirements of your installation.