• Siemens SIRIUS 3RB21 Electronic Overload Relays (S6–S12, Adj. Class)
1 1

Siemens SIRIUS 3RB21 Electronic Overload Relays (S6–S12, Adj. Class)

Siemens SIRIUS 3RB21 Electronic Overload Relays (S6–S12, Adj. Class)

SIRIUS 3RB21 electronic overload relays with adjustable trip class 5E to 30E protect motors from 50 A to 630 A in sizes S6 to S12.

Key features

  • Trip class adjustable: 5E, 10E, 20E or 30E
  • Setting ranges 50-200 A, 55-250 A and 160-630 A
  • Busbar connection or straight-through transformer versions
  • For mounting on contactors and stand-alone installation
  • Auxiliary contacts 1 NO + 1 NC, manual/automatic RESET, TEST and self-monitoring

Specifications

Class 5E/10E/20E/30E adjustable
Product line SIRIUS 3RB2
Aux. contacts 1 NO + 1 NC
Power supply Internal
Brand Siemens
Catalog section IC 10 ch. 7 Protection equipment
Category Electronic Overload Relays
Poles 3
Rated frequency 50/60 Hz
Source Siemens Catalog IC 10 · 2026, p. 7/103-7/103
3RB2153-4FC2 Size: S6 | Setting range: 50–200 A | Motor rating: 30–90 kW | Version: Busbar connection | Connection: Screw (aux. circuit)
3RB2153-4FF2 Size: S6 | Setting range: 50–200 A | Motor rating: 30–90 kW | Version: Busbar connection | Connection: Spring-loaded (aux. circuit)
3RB2153-4FW2 Size: S6 | Setting range: 50–200 A | Motor rating: 30–90 kW | Version: Straight-through transformer | Connection: Screw (aux. circuit)
3RB2153-4FX2 Size: S6 | Setting range: 50–200 A | Motor rating: 30–90 kW | Version: Straight-through transformer | Connection: Spring-loaded (aux. circuit)
3RB2163-4GC2 Size: S10/S12 | Setting range: 55–250 A | Motor rating: 30–132 kW | Version: Busbar connection | Connection: Screw (aux. circuit)
3RB2163-4GF2 Size: S10/S12 | Setting range: 55–250 A | Motor rating: 30–132 kW | Version: Busbar connection | Connection: Spring-loaded (aux. circuit)
3RB2163-4MC2 Size: S10/S12 | Setting range: 160–630 A | Motor rating: 90–355 kW | Version: Busbar connection | Connection: Screw (aux. circuit)
3RB2163-4MF2 Size: S10/S12 | Setting range: 160–630 A | Motor rating: 90–355 kW | Version: Busbar connection | Connection: Spring-loaded (aux. circuit)
Electronic Overload RelaysSiemens
8 product codes available in this family
Sourced direct from KoreaExport-ready supplyCompetitive pricing
RFQ List 0 Email about this

Need a different model, or a part not listed here? Send us your parts list →

Siemens SIRIUS 3RB21 Electronic Overload Relays (S6–S12, Adj. Class)

Brand Siemens·Electronic Overload Relays

Available part numbers (8)

3RB2153-4FC2, 3RB2153-4FF2, 3RB2153-4FW2, 3RB2153-4FX2, 3RB2163-4GC2, 3RB2163-4GF2, 3RB2163-4MC2, 3RB2163-4MF2

How to order

Send the Siemens part numbers and quantities through our RFQ form or to info@prosourcemro.com. We confirm price, availability and lead time within 1 business day — no account needed.

RFQ List 0 →
View full details
Product codes & specifications
0 selected
RFQ List (0)
Product codeSpec
3RB2153-4FC2Size: S6 | Setting range: 50–200 A | Motor rating: 30–90 kW | Version: Busbar connection | Connection: Screw (aux. circuit)
3RB2153-4FF2Size: S6 | Setting range: 50–200 A | Motor rating: 30–90 kW | Version: Busbar connection | Connection: Spring-loaded (aux. circuit)
3RB2153-4FW2Size: S6 | Setting range: 50–200 A | Motor rating: 30–90 kW | Version: Straight-through transformer | Connection: Screw (aux. circuit)
3RB2153-4FX2Size: S6 | Setting range: 50–200 A | Motor rating: 30–90 kW | Version: Straight-through transformer | Connection: Spring-loaded (aux. circuit)
3RB2163-4GC2Size: S10/S12 | Setting range: 55–250 A | Motor rating: 30–132 kW | Version: Busbar connection | Connection: Screw (aux. circuit)
3RB2163-4GF2Size: S10/S12 | Setting range: 55–250 A | Motor rating: 30–132 kW | Version: Busbar connection | Connection: Spring-loaded (aux. circuit)
3RB2163-4MC2Size: S10/S12 | Setting range: 160–630 A | Motor rating: 90–355 kW | Version: Busbar connection | Connection: Screw (aux. circuit)
3RB2163-4MF2Size: S10/S12 | Setting range: 160–630 A | Motor rating: 90–355 kW | Version: Busbar connection | Connection: Spring-loaded (aux. circuit)

Need a different model, or a part not listed here? Send us your parts list →

Related products

All Relays & Switches →