Thermal & Electronic Overload Relays
Overload Relays are essential motor protection devices engineered to safeguard electric motors against overheating caused by prolonged current overloads, locked rotors, or phase failures. The Siemens SIRIUS 3RU21 (bimetallic) and 3RB30 (electronic) overload relay series offer seamless plug-in direct mounting underneath 3RT2 power contactors or standalone installation via DIN-rail adapters. Equipped with test/RESET functionality, integrated 1 NO + 1 NC auxiliary contacts, and wide current setting ranges, they ensure optimal motor reliability in industrial control cabinets.
Key Features:
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Direct Contactor Mounting: Plug-and-play direct pin connection underneath Siemens 3RT2 power contactors without extra wiring.
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Bimetallic & Electronic Options: Choice between traditional thermal bimetal relays (3RU21) and wide-range, energy-efficient electronic overload relays (3RB).
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Phase Loss Sensitivity: Enhanced tripping protection in the event of phase failure to prevent motor winding burnout.
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Manual & Automatic RESET Modes: Flexible reset operation modes (Manual/Auto) with integrated TEST/STOP buttons for control circuit validation.
SIRIUS 3RU Thermal Overload Relays - Size S0 Screw Terminals
Size S0 bimetallic thermal overload relays from the Siemens SIRIUS series featuring robust screw ter..
SIRIUS 3RU Thermal Overload Relays - Size S0 Spring Terminals
Size S0 bimetallic thermal overload relays from the Siemens SIRIUS series featuring vibration-proof ..
SIRIUS 3RU Thermal Overload Relays - Size S00 Screw Terminals
Size S00 bimetallic thermal overload relays from the Siemens SIRIUS series featuring robust screw te..
-500x500.jpg "SIRIUS 3RU Thermal Overload Relays - Size S00 Spring Terminals")
SIRIUS 3RU Thermal Overload Relays - Size S00 Spring Terminals
Size S00 bimetallic thermal overload relays from the Siemens SIRIUS series featuring innovative spri..
SIRIUS 3RU Thermal Overload Relays - Size S2 Screw Terminals
Size S2 bimetallic thermal overload relays from the Siemens SIRIUS series featuring robust screw ter..
SIRIUS 3RU Thermal Overload Relays - Size S3 Screw Terminals
Size S3 bimetallic thermal overload relays from the Siemens SIRIUS series featuring robust screw ter..