Siemens 3RB Overload Relay 1NO + 1NC, 4 A Contact Rating, 250 kW, 3P, SIRIUS

Internal power supply
Auxiliary contacts 1 NO+1NC
Manual/Automatic Reset
Switching position indicator
Test function
Phase failure/unbalance sensitivity

Protect your industrial motors from overheating due to overload with this robust relay from Siemens' SIRIUS Classic range. It functions as part of the motor starter and works by monitoring the current flowing in the circuit. When the current rises, it'll trip above a set limit over a period of time and cut off power to the motor, protecting it from damage. This overload relay has a test function, so you can easily check that it's in good working condition. Manual and automatic reset options enable a quick restart after it's tripped. You can easily connect cables to this relay thanks to its screw terminals, which make installation quick and efficient.

• Power rating of 250kW for heavy-duty industrial use
• Broad operating temperature range of -25°C to +60°C for use in demanding environments
• Thermoplastic housing material is durable and impact resistant
• Light weight of 1.8kg for easy handling

Maintain this relay by carrying out regular cleaning and rust removal. It's also important to check and tighten any loose screws to avoid heat accumulation from partial contacts. Frequent testing with a simulated overload current will flag up any performance issues.

Electronic Overload Relays

The 3RB2 range of Solid State Electronic overloads can be connected directly to Siemens SIRIUS contactors to provide accurate motor overload protection with enhanced single phase sensitivity,Application: Protection of 3 phase AC motors in sinusoidal 50/60Hz network. These relays are not suitable for the protection of single phase or DC loads,Select according to motor full load current and contactor frame size e,g. S00