The SITOP PSE202U 6EP1961-3BA21 is Siemens' 40A redundancy module, decoupling two 24VDC power supplies through integrated diodes to maintain uninterrupted output if one supply fails.

Core Function

Two independent 24VDC supplies connect to the module inputs, each rated up to 20A. Internal diode decoupling prevents a short circuit in one supply from pulling down the other. If either supply drops below the adjustable switching threshold (20-25VDC), the module seamlessly transitions load to the remaining supply. The 40A aggregate output supports high-power loads with N+1 redundancy.

Monitoring and Diagnostics

A green LED indicates both inputs are above threshold. A red LED and isolated changeover relay contact (8A at 240VAC/24VDC) signal when one input falls below the threshold. The adjustable threshold enables customization to specific system voltage requirements.

Installation

Snap-on 35mm DIN rail mounting in a 70mm-wide housing. Screw terminals accept 0.33-10mm wiring for input/output and 0.5-2.5mm for the relay contact. ABS and DNV marine certifications extend deployment to shipboard systems.