Siemens 3RT20171AD02 Contactor — S00 Size, 12 A, 42 VAC Coil
Catalog identity and series context
The 3RT20171AD02 belongs to the Siemens SIRIUS 3RT2017 series, identified by the "3RT20" prefix and size class S00 (the smallest frame in the SIRIUS contactor family). The suffix "1AD02" encodes the coil voltage (AD = 42 VAC) and the auxiliary contact arrangement (1 NC). This MPN represents the 42 VAC coil variant configured with one normally-closed auxiliary contact on a 3PST-NO power pole set.
Key parameters
| Parameter | Value |
|---|---|
| Coil Voltage | 42 VAC |
| Must Operate Voltage | 35.7 VAC |
| Coil Power | 33 VA |
| Contact Rating (Current) | 12 A |
| Contact Form | 3PST-NO (3 Form A) |
| Operate Time | 35 ms |
| Operating Temperature | 25°C ~ 60°C |
| Mounting Type | Chassis Mount, DIN Rail |
| Encapsulation | Box |
| Features | Auxiliary Contacts |
| Base Product Number | 3RT2017 |
In-catalog comparison (42 VAC coil variants)
The table below shows S00 3RT2017 contactors sharing the same coil voltage class. All variants carry 12 A contact ratings, 3PST-NO contact forms, auxiliary contacts, and DIN Rail/chassis mounting unless noted otherwise.
| MPN | Coil Voltage | Must Operate Voltage | Coil Power | Encapsulation | Operate Time |
|---|---|---|---|---|---|
| 3RT20171AD02 | 42 VAC | 35.7 VAC | 33 VA | Box | 35 ms |
| 3RT20171AD01 | 42 VAC | 35.7 VAC | 33 VA | Box | 35 ms |
| 3RT20171AH02 | 48 VAC | 40.8 VAC | 33 VA | Box | 35 ms |
| 3RT20171AB02 | 24 VAC | 20.4 VAC | 37 VA | Bulk | 33 ms |
Why the listed alternates are catalog-peers: Each variant shares the same base product number (3RT2017), size class (S00), contact rating (12 A), contact form (3PST-NO), mounting type, and auxiliary-contact feature. They differ in coil voltage, must-operate voltage, and—in the case of 3RT20171AB02—coil power and encapsulation packaging. The AD01 variant additionally swaps the auxiliary contact from NC to NO while retaining identical electrical ratings.
Selection notes
- Coil voltage determines control-circuit compatibility; the must-operate voltage (35.7 VAC) represents the minimum pickup threshold for the 42 VAC coil.
- The "1NC" auxiliary contact configuration suits power-monitoring or interlock circuits where a normally-closed status signal is required.
- Operating temperature range 25°C ~ 60°C is typical for enclosed panel environments; elevated ambient conditions may affect contact life.
- Box encapsulation indicates individual packaging; bulk-pack variants (e.g., 3RT20171AB02) may suit high-volume assembly.
FAQ
What is the contact arrangement of the 3RT20171AD02? The main poles are configured as 3PST-NO (three normally-open power contacts). The auxiliary contact is one normally-closed (NC) contact.
Can the 3RT20171AD02 be mounted on DIN Rail? Yes — the device supports both chassis mount and DIN Rail mounting.
What is the must-operate voltage for this contactor? The must-operate voltage is 35.7 VAC, which is the minimum coil voltage required to assure contact closure.