Numele complet al produsului: SIRIUS side-mounted auxiliary switch block, 4-pol, 2NU+2NC, terminale cu șuruburi
Stare produs: Întrerupt (PLM PM500). It is an older accessory for 3RT1 contactoare. The new-generation replacement series is 3RH29xx
- Nomenclatura modelului
3RH: SIRIUS auxiliary switches / contactor relay accessories
19: External side-mounted auxiliary contacts for contactors
21: Side snap-on mounting, fits S0~S3 contactor sizes
1: Borne cu șuruburi; 2 = spring-cage terminals (3RH1921-2HA22)
HA: 4-pole side-mounted contact block
22: Configurarea contactului 2 Deschis normal + 2 În mod normal închis (2NU+2NC)
- Parametrii tehnici cheie
- Contacte: 2NU+2NC, 4-pol, conform EN 50012
- Montare: Snap-on side installation on the contactor
- Compatible base unit: SIRIUS 3RT1 motor contactors, frame sizes S0 / S2 / S3
- Terminale: Tip șurub, wire cross-section 0.5~2.5 mm²
- Protecţie: Front face IP20
- Tensiunea nominală de izolație: 690 V (gradul de poluare 3), tensiune de rezistență la impuls 6 kV
- Endurance: Durata de viata mecanica 10 million operating cycles; AC-15 230V electrical life 200,000 cicluri
- Temperatura de functionare: -25 ~ +60 °C; temperatura de depozitare: -55 ~ +80 °C
- Contact reliability: 17 V / 1 mA, max 1 failure within 100 milioane de operațiuni
- Scenarii de aplicare
Side expansion of auxiliary contacts for 3RT1 (S0~S3) Contactoare AC
PLC feedback signals, indicație de stare, circuite de interblocare, fault signal output
Motor start-stop control circuits, ventilator & water pump control panels, low-voltage switchgear cabinets
Nota: Side auxiliary switches can only be fitted on the left side of the contactor. The total number of NC contacts is limited; positively driven contacts must be verified for safety interlock applications.
- Selectarea înlocuirii (Discontinued Upgrade)
Modelul original a fost întrerupt. The corresponding side-mounted unit for new 3RT2 (S0~S3) contactoare:
3RH2921-1DA22 (borna cu șurub, 2NO+2NC side-mounted auxiliary switch)
- Depanare & Inspection Guidelines
- Common failures: Oxidare de contact, contact burning, loose snap-fit clips leading to intermittent feedback signals
- Multimeter test: With the contactor de-energized, NC contacts shall be conducting and NO contacts open; contact status flips when the coil is energized
- Wiring check: Tighten all terminal screws firmly; loose thin wires frequently cause unstable PLC digital inputs
- Înlocuire: Direct snap-on disassembly without touching the main power circuit; always test interlock logic after replacement
- Cross-reference List for the Same Series
3RH1921-1HA22: Borne cu șuruburi, 2NU+2NC, side mount S0–S3 (Întrerupt)
3RH1921-2HA22: Spring-cage terminals, same contact configuration (Întrerupt)
3RH2921-1DA22: New-generation screw-type side-mounted 2NO+2NC (Model de înlocuire)
Siemens 3RT1 Contactor Replacement Overview
3RT1 (S00~S3, ≤95A) este întreruptă (PLM PM500). First-choice official direct replacement: 3RT2 (imported SIRIUS Innovation series). For cost-saving domestic alternatives, select 3RT6 / 3RT5. Larger frame 3RT1 (>95O) remains available with no forced phase-out schedule
- 3RT2 [Importat, Preferred OEM Replacement]
Serie: 3RT20xx, direct replacement for legacy 3RT10xx
Frame size match: S00 / S0 / S2 / S3, AC-3 current range 7A~95A
Replacement rule:
Exemplu: 3RT1024-1BB40 → 3RT2024-1BB40. Keep coil voltage and rated current unchanged; only change the middle digit from 1 la 2.
Critical compatibility note (relevant to your 3RH1921 auxiliary contacts):
Old 3RH1921 cannot be used on 3RT2; you must upgrade to 3RH2921 series auxiliary switches together with the contactor body.
- Large-size 3RT1 (S6 / S10 / S12, Still Active, Not Discontinued)
S6 (3RT105×, Frame S6, 115A~150A, 55kW~75kW @400V)
| Base Order No. | AC-3 Current | Puterea motorului (400V) | Tip terminal | Accesorii potrivite |
| 3RT1054 | 115 O | 55 kW | Şurub / box terminals | Contact auxiliar: 3RH1951; Overload relay: 3RU1156 |
| 3RT1055 | 150 O | 75 kW | Şurub / box terminals | Contact auxiliar: 3RH1951; Overload relay: 3RU1156 |
Complete model examples: 3RT1054-6AF36, 3RT1055-6NB36
S10 (3RT106×, Frame S10, 185A~225A, 90kW~110kW @400V)
| Base Order No. | AC-3 Current | Puterea motorului (400V) | Tip terminal | Accesorii potrivite |
| 3RT1064 | 185 O | 90 kW | Busbar terminals | Contact auxiliar: 3RH1961; Overload relay: 3RU1166 |
| 3RT1065 | 225 O | 110 kW | Busbar terminals | Contact auxiliar: 3RH1961; Overload relay: 3RU1166 |
S12 (3RT107×, Frame S12, 265A~300A, 132kW~160kW @400V)
| Base Order No. | AC-3 Current | Puterea motorului (400V) | Tip terminal | Accesorii potrivite |
| 3RT1075 | 265 O | 132 kW | Busbar terminals | Contact auxiliar: 3RH1971; Overload relay: 3RU1176 |
| 3RT1076 | 300 O | 160 kW | Busbar terminals | Contact auxiliar: 3RH1971; Overload relay: 3RU1176 |
S14 (Extra-large frame, still available)
3RT1096: 400O / 200kW
3RT1097: 500O / 250kW
- Dedicated Accessories for S6/S10/S12 (Not Interchangeable with S00~S3)
(1) Side-mounted auxiliary switches (Base unit already has built-in 2NO+2NC; add-on optional)
S6: 3RH1951
S10: 3RH1961
S12: 3RH1971
Important reminder: 3RH1921 (for small frames) cannot be installed here due to incompatible snap-in geometry.
(2) Plug-in thermal overload relays (direct plug-on mounting with 3RT1)
S6: 3RU1156
S10: 3RU1166
S12: 3RU1176
(3) Mechanical interlocks (for reversing contactor pairs)
S6: 3RT1951
S10: 3RT1961
S12: 3RT1971
- Coil Voltage Suffix Codes (Universal for all frames)
1AB36: AC/DC 24 V
1AD36: AC/DC 48 V
6AF36: AC/DC 110~127 V
6AU36: AC/DC 200~277 V (wide-voltage coil)
- Phase-out Boundary Rules (Critic)
- 3RT101~3RT104 (S00~S3, ≤95A): PM500, fully discontinued. Must migrate to 3RT2 / 3RT6.
- 3RT105~3RT107 (S6/S10/S12): PM300, active production, long-term supply, no end-of-life plan.
- Future upgrade path (if needed): 3RT105 → 3RT205; 3RT106 → 3RT206; 3RT107 → 3RT207. Replace accessories with 3RH2951/2961/2971 accordingly.
- Popular Complete Order Numbers
- 3RT1054-6AF36|S6, 115O, AC/DC 110V coil
- 3RT1055-6NB36|S6, 150O, wide-voltage coil
- 3RT1064-6AU36|S10, 185O, AC/DC 240V coil
- 3RT1065-6AU36|S10, 225O, AC/DC 240V coil
- 3RT1075-6AU36|S12, 265O
- 3RT1076-6AU36|S12, 300O
Contactor,întrerupător de circuit,senzor,Codificator,PLC,Convertor


















NH42-63-318x560.png)



