Siemens 5TT5842-0 SENTRON Insta Contactor — 40 A, 2 NO + 2 NC, 230 V AC Coil
The Siemens 5TT5842-0 is a SENTRON Insta contactor rated for 40 A operational current at AC, with a 230 V AC coil and a contact arrangement of 2 normally-open and 2 normally-closed poles. The 40 A AC-1 rating means it handles resistive loads like lighting and heating banks up to that current; the 4000 W incandescent lamp switching capacity confirms it is sized for large lighting circuits. It occupies 3 modular width units (roughly 54 mm) on a DIN rail, and the IP20 finger-safe enclosure suits installation inside a distribution board or control panel — not for wet or dusty environments.
Mounting and Thermal Considerations
The manufacturer explicitly requires spacers between adjacent devices to allow heat dissipation — do not gang-mount without the specified air gap, or the 4 W per-pole power loss will accumulate and derate the contactor. Dimensions are 71 mm deep, 54 mm wide, 90 mm tall, fitting standard 3-MW DIN-rail enclosures.
Lifecycle and Sourcing
Supplementary devices such as auxiliary contact blocks or shunt trips can be installed on the contactor, extending its functionality without replacing the base unit.