3RB2046-2UB0

Siemens 3RB2046-2UB0 Solid State Class 20 Overload relay with an AMP range from 12.5A - 50A and 1 N.O. and 1 N.C. auxiliary contacts.

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The 3RB20/3RB21 solid-state overload relays are suitable for customers from all industries who want to provide optimum inverse-time delayed protection of their electrical loads (e.g. motors) under normal and heavy starting conditions (CLASS 5 to CLASS 30), minimize project completion times, inventories and power consumption, and optimize plant availability and maintenance management.

The 3RB20/3RB21 solid-state overload relays have been designed for the protection of three-phase motors in sinusoidal 50/60 Hz voltage networks. The relays are not suitable for the protection of single-phase AC or DC loads. The 3RU11 thermal overload relay or the 3RB22/3RB23 solidstate overload relay can be used for single-phase AC loads. For DC loads the 3RU11 thermal overload relays are available. The devices are insensitive to external influences such as shocks, corrosive environments, ageing and temperature changes.

For the temperature range from –25 C to +60 °C, the 3RB20/3RB21 solid-state overload relays compensate the temperature according to IEC 60947-4-1. The 3RB20/3RB21 solid-state overload relays are suitable for the overload protection of explosion-proof motors with "increased safety" type of protection EEx e according to ATEX guideline 94/9/EC. The relays meet the requirements of EN 60079-7 (Electrical apparatus for potentially explosive atmospheres – Increased safety "e").

The 3RB20/3RB21 solid-state overload relays are designed for:
• Inverse-time delayed protection of loads from overloading
• Inverse-time delayed protection of loads from phase unbalance
• Inverse-time delayed protection of loads from phase failure
• Protection of loads from high-resistance short-circuits
(internal ground-fault detection only with 3RB21).

The 3RB20/3RB21 solid-state overload relays are set to the motor rated current by means of a rotary knob. The scale of the rotary knob is shown in amps. With the 3RB21 solid-state overload relay it is also possible to select the trip class (CLASS 5, 10, 20 or 30) using a second rotary knob and to switch the internal ground-fault detection on and off.