Modular contactor, DIN rail mounting, 4NC contacts, 40A ST40-04

Universal solution for controlling electrical circuits

The ST40-04 modular contactor is a reliable device designed to control electrical circuits in building automation installations, HVAC systems, and machine control. Its construction, based on mounting on a standard DIN rail, ensures easy installation and integration with the rest of the equipment. It will work well both in new installations and during the modernization of existing ones.

Functionality and operating parameters

The device operates at a rated voltage of 230V AC, both in the control and power circuit. The rated current of 40A allows for handling medium loads, and four normally closed contacts (4NC) provide the possibility of extended control and protection configurations. The switching capacity for incandescent lamps is up to 16000W. The contactor is made with a degree of protection of IP20, which ensures safety of use in standard environmental conditions.

Construction and mounting

The compact housing with a width of 3 modules minimizes the space occupied in the switchgear cabinet. Mounting is done by snapping onto a standard 35mm DIN rail - this solution is appreciated by installers for its speed and convenience. Screw terminals allow connection of wires with a cross-section of up to 16 mm². The insulation voltage is 4kV, which guarantees the safety of the device. The contactor also has a manual control slider (although it is not activated), which may be useful during testing or maintenance. Compliance with IEC 61095 confirms its quality and safety.