The Siemens SENTRON 4AC3208-1 is an 8 VA bell transformer designed for intermittent-duty signaling applications in residential and commercial buildings. It steps down 230 V AC mains to safe 8 V or 12 V SELV secondary voltages — the standard levels for electromechanical doorbells, chimes, gongs, buzzers, and door opener actuators. An integrated PTC thermistor provides automatic resetting short-circuit and overload protection, eliminating the need for external fusing. The compact 2-module (36 mm) DIN rail housing fits standard distribution boards alongside circuit breakers and RCDs.

Key Features

• Dual 8 V / 12 V secondary outputs — compatible with standard bell and buzzer products
• Built-in PTC protection — auto-reset after fault clearance
• Intermittent duty rating — optimized for short-duration bell and gong operation
• SELV safety extra-low voltage with 4 kV primary-to-secondary isolation
• Safety class II per EN 61140 — no earth connection required
• 2-module (36 mm) DIN rail form factor — fits standard distribution boards
• 91% permissible humidity rating for typical building environments

Technical Data

Applications

Residential and commercial building signaling: doorbell systems, apartment intercom buzzers, gate/door openers, hotel room chimes, and office paging gongs. The SELV output ensures safe installation in accessible locations without additional protective measures.