Modular Contactor FF ST25-30 25A 3NO 0NC 230V AC

The FF Modular Contactor ST25-30 is a compact DIN-rail mounted switching device rated for 25 A with a 230 V AC control coil. Configured with three normally open main contacts, it is intended for switching lighting, motors and heating circuits in residential and light-commercial electrical installations. Its modular form factor allows installation inside distribution boards alongside circuit breakers and other modular components, providing space-efficient control and automation functions.

Advantages

The modular design reduces panel space requirements and simplifies wiring in distribution boards. With three normally open contacts, the contactor can switch multiple circuits or multi-phase loads within the 25 A limit. A 230 V AC coil makes the unit compatible with standard control voltages used in many building automation and control systems. The device is suitable for DIN-rail mounting and integrates with standard modular electrical equipment.

Suitable for

• Switching lighting circuits in residential and commercial distribution boards
• Controlling small motors and pumps within the 25 A rating
• Switching heating elements and HVAC control circuits
• Automation and remote control applications using 230 V AC control signals

When it may not be suitable

This contactor is not intended for direct switching of loads that exceed the 25 A rated current or for heavy industrial motors requiring larger motor starters or soft starters. It may not be appropriate where neutral or complex control contact arrangements are required beyond three normally open contacts.

Key specifications

• Rated current: 25 A
• Control coil voltage: 230 V AC
• Main contacts configuration: 3 normally open (3NO)
• Mounting: DIN-rail, modular form factor
• Primary application: lighting, motor and heating circuit switching in residential and light-commercial installations

How to use

Install the contactor on a DIN-rail inside a distribution board following local electrical regulations. Connect the load conductors to the main contact terminals and the control circuit to the 230 V AC coil terminals, ensuring correct polarity and secure wiring. Verify that the total current of switched loads does not exceed 25 A and confirm coordination with upstream protective devices. Test switching operation after installation to confirm correct wiring and function before commissioning.

What to consider before purchase

• Confirm the total switched load current does not exceed 25 A
• Ensure the control system provides a 230 V AC switching signal
• Verify that three normally open contacts meet the required control logic
• Check available DIN-rail space in the distribution board for a modular device

Usage recommendations

Use the contactor with appropriate overcurrent and short-circuit protection upstream. For motor loads, check starting currents and, where necessary, use suitable motor protection devices or starters. Periodically inspect terminal connections for tightness and signs of overheating to maintain reliable operation.