© Siemens AG
SIRIUS 3RN2
Siemens thermistor relay for direct motor protection with PTC sensors in the winding, in 17.5 mm and 22.5 mm widths, with a 24 to 240 V AC/DC supply and ATEX-approved versions
Price and delivery time are given after a technical review.
SIRIUS 3RN2 is the Siemens thermistor motor protection relay (PTC motor protection). Instead of measuring current it monitors the winding temperature directly: the motor manufacturer fits type A PTC sensors in the windings, and the relay switches its output off when a sensor reaches its rated response temperature (TNF). There is nothing to set on the device; the trip point is defined by the sensor.
That is why 3RN2 also protects where a current-based overload relay reacts late or not at all: heavy starting, frequent switching, long starting and braking, poor cooling, high ambient temperature and converter operation at low speed.
3RN2011, 3RN2012-.B.30, 3RN2013 and 3RN2023 are approved for protecting explosion-proof motors of type of protection Ex e, in Group II category (2) for gas (G) and dust (D) (certificate PTB 15 ATEX 3011), and reach SIL 1 to EN 50495. The relay itself must not be installed inside the hazardous area.
The control circuit must be wired so that a relay trip stops the motor immediately, even when the motor is fed from a converter. Automatic reset is not permitted where an unexpected restart endangers people or equipment, and in a hazardous area the relay must not run with Y1 and Y2 permanently jumpered.
| Model | Order code | Code type | Attributes | Request |
|---|---|---|---|---|
| 3RN2000-1AW30واحد فشردهٔ ۱۷٫۵ میلی‌متری با یک کنتاکت تبدیل، ریست خودکار و یک LED (تریپ)؛ ریشهٔ کنتاکت تبدیل به A1 وصل است؛ سنسور بایمتال هم قابل اتصال است؛ بدون ATEX | 3RN2000-1AW30 | Exact code |
| Request 3RN2000-1AW30 |
| 3RN2010-1CW30واحد فشردهٔ ۱۷٫۵ میلی‌متری با یک NO و یک NC، ریست خودکار و دو LED (آماده و تریپ)؛ سنسور بایمتال قابل اتصال است؛ بدون ATEX | 3RN2010-1CW30 | Exact code |
| Request 3RN2010-1CW30 |
| 3RN2010-2CA30همان 3RN2010 با ترمینال فنری (push-in) و تغذیهٔ ۲۴ ولت AC/DC | 3RN2010-2CA30 | Exact code |
| Request 3RN2010-2CA30 |
| 3RN2011-1BW30واحد استاندارد ۲۲٫۵ میلی‌متری با دو کنتاکت تبدیل، ریست دستی یا از راه دور (با قطع و وصل تغذیه)، تشخیص قطعی سیم و اتصال کوتاه سنسور، دکمهٔ TEST/RESET و تأییدیهٔ ATEX | 3RN2011-1BW30 | Exact code |
| Request 3RN2011-1BW30 |
| 3RN2012-1BW31نسخهٔ دوپایدار: با قطع تغذیه خروجی تغییر حالت نمی‌دهد و آخرین وضعیت را نگه می‌دارد (در این حالت موتور پایش نمی‌شود)؛ ریست دستی، خودکار یا از راه دور؛ حافظهٔ خطای غیرفرار؛ بدون ATEX | 3RN2012-1BW31 | Exact code |
| Request 3RN2012-1BW31 |
| 3RN2013-1BW30واحد استاندارد با ATEX، جداسازی ایمن همهٔ مدارها (protective separation)، ریست دستی، خودکار یا از راه دور، حافظهٔ خطای غیرفرار؛ برگهٔ داده SIL 1 و PL c را اعلام می‌کند | 3RN2013-1BW30 | Exact code |
| Request 3RN2013-1BW30 |
| 3RN2013-1GW30همان 3RN2013 با دو کنتاکت تبدیل روکش‌طلای سخت برای خروجی سازگار با ورودی‌های الکترونیکی | 3RN2013-1GW30 | Exact code |
| Request 3RN2013-1GW30 |
| 3RN2023-1DW30دو مدار سنسور مستقل: مدار هشدار (یک NO، فقط ریست خودکار) و مدار قطع (یک CO، ریست دستی، خودکار یا از راه دور)؛ سه LED؛ ATEX؛ جداسازی ایمن | 3RN2023-1DW30 | Exact code |
| Request 3RN2023-1DW30 |
| 3RN2 article number scheme (push-in example)ساختار کد سفارش: رقم هشتم (بعد از خط تیره) نوع ترمینال است، ۱ پیچی و ۲ فنری (push-in)؛ حرف بعد کنتاکت‌ها را مشخص می‌کند (A یک تبدیل، B دو تبدیل، C یک NO و یک NC، D یک NO و یک CO، G دو تبدیل روکش‌طلا) و حرف بعد ولتاژ تغذیه را (A ۲۴ ولت، W ۲۴ تا ۲۴۰ ولت). این ردیف فقط شکل کد است، نه شمارهٔ تأییدشده | 3RN2013-2… | Example code |
| Request 3RN2 article number scheme (push-in example) |
| Protection principleProtection principle | Direct winding-temperature monitoring with PTC sensors |
|---|---|
| Connectable sensorsConnectable sensors | Type A PTC (IEC 60947-8); bimetallic switch on 3RN2000 and 3RN2010 only |
| Versions in the familyVersions in the family | 3RN2000, 3RN2010, 3RN2011, 3RN2012, 3RN2013, 3RN2023 |
| StandardsStandards | IEC 60947-8, IEC 61000-6-2, IEC 61000-6-4 |
| Trip and restart temperature against TNFTrip and restart temperature against TNF | 3 sensors: TNF +3 K / TNF -7 K; 6 sensors: TNF -4 K / TNF -19 K |
|---|---|
| Reset threshold (sensor resistance)Reset threshold (sensor resistance) | < 1500 Ω |
| Maximum sensor cable length, without short-circuit detection (3RN2000, 3RN2010)Maximum sensor cable length, without short-circuit detection (3RN2000, 3RN2010) | 2 x 2800 m (2.5 mm²); 2 x 1500 m (1.5 mm²); 2 x 500 m (0.5 mm²) |
| Maximum sensor cable length, with short-circuit detection (3RN2011, 3RN2012, 3RN2013, 3RN2023)Maximum sensor cable length, with short-circuit detection (3RN2011, 3RN2012, 3RN2013, 3RN2023) | 2 x 250 m (2.5 mm²); 2 x 150 m (1.5 mm²); 2 x 50 m (0.5 mm²) |
| Wire-break and short-circuit detection in the sensor circuitWire-break and short-circuit detection in the sensor circuit | 3RN2011, 3RN2012, 3RN2013, 3RN2023 |
| Rated control supply voltageRated control supply voltage | 24 V AC/DC; 24 ... 240 V AC/DC |
|---|---|
| Output contactsOutput contacts | 1 CO; 1 NO + 1 NC; 2 CO; 1 NO + 1 CO (3RN2023) |
| Contact current AC-15 at 250 VContact current AC-15 at 250 V | 3 A |
| Contact current DC-13Contact current DC-13 | 1 A at 24 V; 0.2 A at 125 V; 0.1 A at 250 V |
| Output operating principleOutput operating principle | Closed-circuit principle (monitors loss of supply); exceptions: warning output of 3RN2023 and bistable 3RN2012-.BW31 |
| Tolerated supply dipTolerated supply dip | < 30 ms |
| Reset modesReset modes | 3RN2000/3RN2010: auto; 3RN2011: manual and remote; 3RN2012/3RN2013/3RN2023: manual, auto and remote |
|---|---|
| Non-volatile fault memoryNon-volatile fault memory | 3RN2012, 3RN2013, 3RN2023 |
| Self-test and test functionSelf-test and test function | Self-test at power-up (about 0.6 s); TEST/RESET button held > 2 s simulates a trip |
| LED indicatorsLED indicators | 3RN2000: TRIPPED; 3RN2010 to 3RN2013: READY, TRIPPED; 3RN2023: READY, WARNING, TRIPPED |
| ATEX approvalATEX approval | Ex II (2) G and D, PTB 15 ATEX 3011 (3RN2011, 3RN2012-.B.30, 3RN2013, 3RN2023) |
|---|---|
| Functional safety (ATEX versions)Functional safety (ATEX versions) | SIL 1 (IEC 62061, IEC 61508), PL c (EN ISO 13849-1) |
| Protective separation of circuitsProtective separation of circuits | 3RN2013, 3RN2023: up to 300 V |
| Dimensions (width x height x depth)Dimensions (width x height x depth) | 17.5 or 22.5 x 100 x 90 mm |
|---|---|
| MountingMounting | Snap-on 35 mm DIN rail (EN 60715) or screw mounting with adapter; any position |
| TerminalsTerminals | Removable; screw-type or spring-loaded (push-in) |
| Ambient temperature, operationAmbient temperature, operation | -25 ... +60 °C |
SIRIUS terminal, 2-pole, screw-type, 1 x 2.5 mm² (3ZY1122-1BA00)
Spare 2-pole screw-type terminal for 3RN2 devices
SIRIUS terminal, 2-pole, push-in, 1 x 2.5 mm² (3ZY1122-2BA00)
Spare 2-pole push-in terminal for 3RN2 devices
SIRIUS lugs for screw fastening (3ZY1311-0AA00)
Lugs for screw fastening instead of a DIN rail (12 units per pack)
Coding pins for SIRIUS terminals (3ZY1440-1AA00)
Coding pins that prevent terminals from being swapped
Manual
SIRIUS 3RN2 thermistor motor protection relay, manual
SIRIUS 3RN2 thermistor motor protection relay, manual
Language: English · Version 10/2016
Brochure
SIRIUS 3RN2 thermistor motor protection relays, brochure
SIRIUS 3RN2 thermistor motor protection relays, brochure
Language: English · Version 01/2019
Catalog
SIRIUS relays, chapter 12 of the Industrial Control Catalog IC 10 (Siemens Canada 2019)
SIRIUS relays, chapter 12 of the Industrial Control Catalog IC 10 (Siemens Canada 2019)
Language: English · Version 2019
Brochure
Monitoring, Controlling and Switching with SIRIUS Relays
Monitoring, Controlling and Switching with SIRIUS Relays
Language: English · Version 2019
Data sheet
Data sheet 3RN2013-1BW30
Data sheet 3RN2013-1BW30
Language: English
Data sheet
Data sheet 3RN2010-1CW30
Data sheet 3RN2010-1CW30
Language: English
Data sheet
Data sheet 3RN2023-1DW30
Data sheet 3RN2023-1DW30
Language: English
An overload relay measures current, whereas 3RN2 reads the real winding temperature from the PTC sensor, so it also protects during heavy starting, frequent switching, poor cooling or high ambient temperature. It is not always a full replacement: on motors whose rotor heats up faster than the stator, temperature detection in the stator winding can come too late and the standards ask for additional protection such as an overload relay. For frequent starting and braking Siemens recommends combining both: the overload relay is set higher and 3RN2 monitors the winding temperature.
A type A PTC sensor to IEC 60947-8; normally the motor manufacturer fits one sensor in each winding overhang and the sensors are connected in series. A bimetallic switch (such as Klixon or Thermoclick) can only be connected to 3RN2000 and 3RN2010, because its resistance is practically zero below the opening temperature and short-circuit detection is not possible. Never use a bimetallic switch in an explosive atmosphere.
If auto reset and a bimetallic sensor are enough, take 3RN2000 (one changeover contact) or 3RN2010 (one NO and one NC, or two changeover contacts). If you need wire-break and short-circuit detection and manual reset, go for 3RN2011, 3RN2012 or 3RN2013; all three have ATEX except the bistable 3RN2012-.BW31. 3RN2013 also gives protective separation of the circuits, and 3RN2023 is for when you want a warning signal from a second sensor in addition to tripping.
Only where an unexpected restart of the motor does not endanger people or equipment. When the relay resets itself after the sensor has cooled, the motor must not start again on its own, so a separate ON button has to be in the circuit. In a hazardous area permanent automatic reset (Y1 and Y2 jumpered) is not allowed.
Yes; Siemens lists protection at low speed with frequency converters as one of the main uses of 3RN2. The control circuit must be wired so that the machine or plant stops immediately when the relay trips, even when the motor is fed from a converter.
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Send your order code or requirement; after a technical review we give you the price and delivery time.