SENTRON 5SP3740-2 — 40 A Class E MCB for Meter-Panel Infrastructure
The Siemens 5SP3740-2 is a SENTRON main miniature circuit breaker, 1-pole (1P) construction, rated 40 A at 30 °C with a Class E tripping characteristic. Class E is a Siemens-specific characteristic that blends thermal-magnetic and electronic trip elements — it provides a high short-circuit withstand (25 kA) while maintaining selectivity with upstream fuses or breakers in meter-panel configurations. The 1.5-module-width footprint (89.5 mm deep, 151.3 mm high) fits standard DIN-rail enclosures, with busbar fastening for ganged installation. Temperature derating is published: 38 A at 40 °C, 37 A at 45 °C, 36 A at 50 °C, 35 A at 55 °C — factor this into continuous-load planning if the panel ambient runs above 30 °C.
Sourcing & Lifecycle — Current Production, No LTB Window
For BOM-freeze or compliance documentation needs, the SENTRON series carries standard IEC/EN certifications. The 25 kA rating per EN 60898 is the governing standard for residential and commercial final-circuit protection in most European and Asia-Pacific markets.
Integration — Meter-Panel Lower-Section Installation, Spring-Loaded Outgoing
Installation position is stipulated for the lower section of the meter panel, with infeed at the box terminal. The outgoing feeder uses spring-loaded terminals — no screw torque required, which speeds panel assembly and reduces QA checks on terminal tightness. Wire range accepts 2.5–50 mm² solid or stranded copper. Sealable design allows utility or inspector locking. Shock resistance is 30 g, 3 impacts at 11 ms duration — sufficient for transport and seismic events in fixed installations.
Electrical Ratings — Insulation, Surge, and Selectivity Headroom
Insulation voltage rated at 690 V, surge voltage resistance at 6 kV — this exceeds typical 230/400 V distribution requirements, providing margin for transient events and coordination with upstream SPDs.