The Siemens 3RU1116-1EB0-ZW97 is a SIRIUS thermal overload relay in Size S00, Trip Class 10, designed for motor protection. It mounts directly onto a Siemens contactor (contactor mounting per), saving panel space and eliminating interwiring between the relay and contactor — a common panel-building practice for compact motor starter assemblies. The relay is rated for screw-type terminals on both the main current circuit and auxiliary/control circuit, accepting solid conductors from 0.5 to 1.5 mm² (two per terminal) and 0.75 to 2.5 mm² (two per terminal), with equivalent AWG ranges for auxiliary contacts: 2x (20...16) and 2x (18...14).
Trip Class 10 is the standard for general-purpose induction motors — it allows enough inrush time for a direct-on-line start but protects against sustained overloads that would damage winding insulation. The auxiliary contact ratings cover common control voltages: 1 A at 24 V, 3 A at 120 V, 2 A at 230 V, and 1 A at 400 V — so the same relay can signal a PLC input or drop out a holding contactor across a range of control supplies. The relay dissipates 1.9 W per pole (5.7 W total for three poles), which is modest for a Size S00 device — no special ventilation required in a standard IP20 enclosure. With IP20 protection on the front and finger-safe touch protection, it's suitable for installation in enclosed control panels where accidental contact with live parts is prevented by the enclosure door. Surge voltage resistance rated at 6 kV ensures the relay withstands typical switching transients in industrial environments without nuisance failure.
Mounting and environmental considerations
The relay occupies a 45 mm wide by 87 mm high by 78 mm deep footprint — standard Size S00 dimensions that fit alongside S00 contactors on a DIN rail or mounting plate. Clearance requirements are minimal: 0 mm upwards, forwards, backwards, and downwards, with only 6 mm needed at the sides — allowing dense packing in multi-starter panels. Mounting position is flexible: the relay can be installed on a vertical surface with ±135° rotation or ±45° tilt front-to-back, giving panel builders options for tight layouts. Operating temperature range is -20 to +70 °C, storage and transport range is -55 to +80 °C, and it operates in up to 100 % relative humidity — suitable for unconditioned industrial environments. Shock resistance rated at 8g for 10 ms means it can be installed on machinery subject to vibration without false trips.
It carries ATEX approval (DMT 98 ATEX G 001) for use in potentially explosive atmospheres. Substance prohibition date of 07/01/2006 aligns with RoHS compliance expectations — the relay is manufactured without restricted substances as defined by EU directives.