Siemens 3RT20174AR61 Electromechanical Contactor

Overview

In a motor branch circuit, this S00-frame contactor occupies minimal DIN rail or chassis space while performing the switching function for a 12 A load at 400 VAC. The catalog entry lists coil power at 43 VA and must-operate voltage at 374 VAC, but critical coordination data—breaking capacity (Icu/Ics), AC-3 utilization classification, and coil inrush vs. sealed VA—are not present in the supplied fields. Selection must not proceed on short-circuit coordination or thermal coordination until the Siemens SIRIUS 3RT2017 datasheet is consulted.

Key Parameters (from catalog fields)

Verification required before selection

• Breaking capacity (Icu/Ics) and coordination class (Type 1 / Type 2) — not supplied.
• AC-3 utilization category — the contactor class for inductive motor switching.
• Coil inrush vs. sealed power — 43 VA is a single figure; control transformer sizing requires both.
• Maximum mechanical and electrical endurance cycles — not listed.
• Terminal torque and wire range — not in catalog fields.
• Certifications — UL, CE, or IEC 60947 suitability not confirmed in supplied data.

Ordering Code / Family Context

The prefix 3RT2017 identifies the SIRIUS 3RT2 series, S00 size, with a 12 A thermal current rating (Ith). The subsequent characters encode coil voltage and auxiliary contact type. In the Siemens numbering scheme:

• R in position 9 → 440 VAC coil (400 V class)
• 6 in position 10 → auxiliary contact configuration (1 = NO, 2 = NC)
• 1 in position 11 → coil control voltage variant

The alternates share the same 3RT2017 base part number but differ in coil voltage (K = 120 VAC, N = 220 VAC, G = 110 VAC, B = 24 VAC) and in auxiliary contact polarity (61 = NO, 62 = NC). This pattern permits side-by-side coil voltage substitution within the same frame size, but the auxiliary contact polarity change (61 vs. 62) is a functional difference for control circuit wiring.

Integration Notes

The catalog confirms DIN rail or chassis mounting for S00, which implies a compact form factor suitable for motor starter combinations with overload relays (e.g., 3RU2116/3RB3 series). The box encapsulation suggests basic protection against dust; IP rating is not specified and should be confirmed for the specific enclosure.

The one NO auxiliary contact provides a feedback or interlock path in the control circuit without requiring an external relay. When combining with an overload relay, verify that the auxiliary contact allocation meets the required feedback and safety interlock count.

Coil VA of 43 VA at 440 VAC implies a control transformer or switching device must be sized for inrush; the single figure prevents precise sealed vs. inrush breakdown from the catalog. The must-operate voltage of 374 VAC (85% pickup) aligns with IEC standards but verify that the control supply can sustain this under minimum operating conditions.

Operating temperature range of 25°C to 60°C is narrower than many industrial contactors (typically −25°C to +60°C); confirm that the enclosure ambient does not exceed 60°C at the contactor location.

Selection / Substitution Guidance

Substitution of 3RT20174AR61 with any alternate requires verifying:

1. Coil voltage match — The alternate must match the control voltage (do not substitute a 110 V or 220 V coil for a 440 V coil in a 400 V system without redesign).
2. Contact configuration — 61 suffix provides NO auxiliary; 62 suffix provides NC auxiliary. Confirm the control circuit requires NO vs. NC feedback.
3. Coordination class — All listed parts appear to be the same series; confirm that any alternate maintains the same Icu/Ics and coordination class required by the motor feeder design.
4. Environmental rating — Operating temperature, IP, and certifications must meet the installation requirements.

The 12 A contact rating and 400 VAC switching voltage are common across all alternates. The coil voltage difference is the primary variable; the auxiliary contact type is the secondary variable.

Similar Catalog Parts

The catalog returned eight alternates, all sharing the 3RT20174A prefix and 3RT2017 base number. The key differentiators are coil voltage and auxiliary contact polarity.

Why they appear similar: All parts share the same 3RT2017 base product number, the same S00 frame size, the same 12 A contact rating, the same box encapsulation, the same mounting type, the same operate time, and the same auxiliary contact feature. The catalog similarity scores reflect shared parameters and prefix proximity. The sole functional variable among these three alternates is coil voltage (120 V, 220 V, and 110 V respectively vs. 440 V in the primary), which dictates must-operate thresholds and suitability for different control systems. Coil power also differs for the 120 V variant (36 VA vs. 43 VA), suggesting a different coil design for lower voltage.

Substitution across coil voltage families requires redesign of the control circuit; these are not drop-in replacements without verifying coil voltage compatibility.

Additionally, 3RT20174AR62, 3RT20174AK62, 3RT20174AN62, 3RT20174AG62, and 3RT20174AB02 share the same series parameters but carry the NC auxiliary contact variant (62 suffix). They differ from the primary by contact polarity and, in some cases, coil voltage. They are not substitutes for the primary if the NO auxiliary contact is required for the control logic.

FAQ

Q: Can 3RT20174AK62 substitute for 3RT20174AR61 if the control voltage is 120 VAC? A: Only if the application control voltage is 120 VAC. The coil voltage must match the control system; a 120 VAC coil cannot be applied to a 400/440 VAC coil circuit. The NC auxiliary (62) vs. NO auxiliary (61) is also a functional difference that must align with the control circuit design. Verify Icu/Ics coordination and mechanical mounting before use.

Q: Does 3RT20174AR61 meet IEC 60947-4-1 for AC-3 motor switching at 12 A / 400 V? A: The catalog fields do not list the AC-3 utilization category, breaking capacity Icu, or coordination class. The 12 A rating and 400 VAC title suggest suitability for light motor duty, but the official Siemens datasheet for the 3RT2017 series must be consulted to confirm IEC certification and coordination type (Type 1 or Type 2).

Q: What is the maximum cable size or terminal torque for the power contacts? A: The data source did not provide terminal torque specifications, wire range, or termination type. These details are critical for proper installation and are available in the Siemens datasheet for the 3RT2017 series.