What the 20 A rating means for your buffer circuit
The Siemens 6EP4136-3AB00-1AY0 is a SITOP UPS1600 DC UPS module rated 20 A continuous at 24 V DC input, with a 60 A peak capability for starting loads or bridging short sags. It operates from a 21–29 V DC input range, so it works with a standard 24 V battery bank or a regulated 24 V power supply — the output voltage follows the input minus about 0.2 V drop through the module.
DIN rail fit and panel clearance
The enclosure is 50 mm wide, 125 mm deep, and 139 mm tall, snapping onto a standard DIN rail EN 60715 35x7.5/15 — the 50 mm width means it takes up two standard 25 mm-wide slots on the rail. IP20 rated — suitable for clean, dry control cabinet environments; not for washdown or outdoor use without an enclosure.
Battery backup and status signaling
This module is designed for buffered operation with external batteries — it monitors battery voltage and provides three floating changeover contacts for status: OK (green LED), alarm (red LED), and battery > 85% charge (green LED with NO contact). A prewarning triggers at battery voltage below 20.4 V DC, and a flashing red LED at ~0.25 Hz signals battery replacement is needed — the floating contacts can switch DC 60 V/1 A or AC 30 V/1 A for connection to a PLC or annunciator. The USB interface (design of the interface: USB) allows connection to a PC for configuration and monitoring via Siemens SITOP software — useful for logging buffer events and setting thresholds.
Approvals and environmental range
Carries cULus listing to UL 508 and CSA C22.2 No. 107.1 (File E197259), plus CE, C-Tick, EAC, and shipbuilding approvals from ABS and DNV GL — accepted in North American, European, Australian, and marine installations. EMC compliance: EN 55022 Class B for conducted and radiated emissions, and EN 61000-6-2 for industrial immunity — suitable for CE-marked panels without additional filtering.
For a line-down replacement or new build, the 20 A rating covers most 24 V control circuits drawing up to 480 W continuous; the 60 A peak handles motorized valve inrush or contactor pick-up without tripping.