Siemens 5TT5833-0 SENTRON Insta Contactor — 25 A, 4 NC, 230 V AC Coil
The Siemens 5TT5833-0 is a SENTRON Insta contactor with four normally-closed (NC) contacts, designed for switching loads up to 25 A at 230 V AC, with a maximum operating voltage of 440 V. The contactor coil is rated for 230 V AC. This is a 2-module-width unit (36 mm wide) with an IP20 protection class, intended for installation in distribution boards or control panels where normally-closed switching is required.
Key Ratings and What They Mean for Fit
The 25 A AC rated operational current is the continuous current the main contacts can carry in AC-1 duty (resistive load). For motor or inductive loads, derating applies per the manufacturer's data. The 230 V AC coil voltage must match the control circuit supply; a 24 V DC coil variant would be a different order code. The 440 V maximum operating voltage sets the ceiling for the line voltage the contacts can safely switch — this contactor is suitable for 230/400 V three-phase systems where the line-to-line voltage does not exceed 440 V. The four NC contacts are closed when the coil is de-energized. This configuration is typically used for fail-safe circuits (e.g., holding an emergency-stop loop) or for loads that must be normally powered when the contactor is off. With zero NO contacts, this part cannot be used for a standard motor start/stop where the main power contacts are NO.
Installation and Panel Integration
The 5TT5833-0 occupies 2 modular width units (36 mm) on a DIN rail. Its depth of 71 mm and height of 90 mm fit standard distribution board cutouts. The manufacturer explicitly notes that spacers must be provided between adjacent devices to ensure adequate heat dissipation — this is not optional; omitting spacers can cause thermal tripping or contact welding at full rated current. The IP20 rating means it is protected against solid objects larger than 12 mm (fingers) but not against water ingress; it is intended for dry indoor enclosures only.