The Siemens SITAS 4AT3632-8DD40 is the flagship of the SITAS single-phase transformer range — the largest control transformer Siemens offers, rated 6,300 VA continuous with a staggering 22,500 VA short-time (S6) capacity. This is the transformer you specify when a single unit must power the entire control system of a major industrial facility: every contactor, every relay, every PLC rack, every HMI, and every field instrument loop. The eleven primary taps span 550 V to 208 V for any global mains; the dual 2×115 V secondary delivers 27.4 A per winding in series or 54.8 A in parallel. Like the 4AT3612, it features class H (155°C) insulation with 55°C ambient tolerance — built for the world's harshest electrical environments. The additional 1,300 VA over the 4AT3612 and extra 3,500 VA short-time capacity come at a weight premium of approximately 12 kg, reflecting heavier-gauge windings and a more substantial core assembly.

Key Features

• 6,300 VA continuous — the largest single-phase SITAS control transformer
• 22,500 VA short-time (S6) — handles massive simultaneous contactor inrush
• 11 universal primary taps (550–208 V) for worldwide installation
• 2×115 V secondary: 27.4 A series, 54.8 A parallel
• Insulation class H (155°C) with 55°C ambient — extreme environment ready
• 94% efficiency, IP00, 194 × 169 × 320 mm, ~58 kg
• UL/CSA recognized, CE, EAC certified

Technical Data

Applications

The ultimate industrial control power solution: complete motor control center lineups in automotive plants, total control power for steel rolling mill auxiliaries, mining process plant-wide control systems, oil refinery motor control buildings, and power generation station auxiliary panels. The 6.3 kVA rating eliminates the need for multiple smaller transformers, simplifying panel design, reducing component count, and improving overall system reliability. The class H insulation with 55°C ambient rating ensures decades of service in the most thermally challenging installations.