Siemens Overload Relay Price List: Navigating Costs and Value with Simply Buy

When checking the Siemens overload relay price list, you’ll find compact bimetal models starting affordably, while advanced electronic options cost more for added features. The final price depends on the current range, reset type, and integration needs, which companies like Simply Buy can help you navigate and choose.

Understanding Siemens SIRIUS Thermal Overload Relays (3RU Series)

A Siemens SIRIUS thermal overload relay (3RU series) protects motors from overheating and damage caused by overload or phase failure. Using a bimetal strip mechanism, the relay disconnects the motor when unsafe currents persist, safeguarding both equipment and personnel.

Why They Matter

• Adjustable trip settings to match the motor’s Full Load Amps (FLA).
• Direct mounting beneath Siemens 3RT contactors for compact starters.
• Auxiliary contacts (95–96 NC, 97–98 NO) for coil protection and signaling.
• Reset selector for manual or automatic reset modes.
  

These features make Siemens thermal overload relays trusted across industries where reliable motor protection and ease of use are critical. Examples include HVAC, automation, and machinery.

Siemens Overload Relay Price List

When reviewing a Siemens overload relay price list, you’ll notice costs vary depending on the series, current rating, and whether the relay uses bimetal (thermal) or electronic sensing

• Small 3RU relays (up to ~12 A): Basic Siemens bimetal overload relays in the S00 frame typically cost $20–$50 USD. They are compact, reliable, and well-suited for fractional to small horsepower motors.
  Mid-range 3RU relays (12–50 A): Popular for industrial motors, these units often cost between $100 and $150. For instance, a 3RU1136 (≈32 A) is commonly listed between $130 and $180.
• Large 3RU relays (50–100 A): Designed for bigger motors, these models range from $180–$250 depending on supplier. They remain cost-effective compared to electronic versions.
  
• Electronic 3RB relays: Solid-state designs offering adjustable trip classes and advanced features such as phase-loss detection. Prices start around $150–$250 for smaller models, climbing above $500 for heavy-duty units rated up to 630 A.

Factors impacting cost include current range and frame size, trip technology (thermal vs. electronic), optional accessories (like remote reset), and supplier pricing policies.

At Simply Buy, we stock the full range of Siemens SIRIUS thermal overload relays and electronic models. Our online catalog doubles as a Siemens overload relay price list, and customers can request tailored quotes for bulk orders or specialized applications.

Step-by-Step Installation Guide

Installing a Siemens SIRIUS 3RU thermal overload relay is straightforward but requires care. Always follow the Siemens thermal overload relay manual and observe lockout/tagout procedures.

1. Safety First

Disconnect all power and verify circuits are de-energized with a multimeter. Follow lockout-tagout (LOTO) policies and wear PPE before starting work.

2. Mounting the Relay

Snap the 3RU relay directly beneath a compatible Siemens 3RT contactor (e.g., 3RT505) to form a compact motor

starter. For standalone use, mount via DIN rail or adapter. Ensure the relay is upright, secure, and aligned.

3. Power Wiring (Main Circuit)

Route the contactor’s three outputs into the relay’s inputs (2T1, 4T2, 6T3). Connect motor leads to the relay outputs (T1, T2, T3). Tighten screws to Siemens torque specs and check continuity to confirm correct phase alignment.

4. Control Circuit Wiring

Wire the NC contact (95–96) in series with the contactor coil (A1–A2). This ensures the coil drops when the relay trips. Use the NO contact (97–98) for indication lamps, alarms, or PLC inputs. Test wiring with the relay’s built-in TEST function.

5. Setting the Current

Adjust the dial to match the motor’s full-load current (per the motor nameplate). Example: for a 10 A motor, set the dial at 10 A. Choose Manual (M) or Automatic (A) reset mode on the relay front.

At this stage, the relay is installed. Re-check connections, remove tools, and supervise a first motor run to confirm proper operation.

How to Reset a Siemens SIRIUS Overload Relay

When an overload occurs, the relay must be reset before restarting.

Identify the Trip

The relay’s front trip indicator shows when it has tripped.

Allow Cooling Time

The bimetal elements must cool before the relay resets. This can take several minutes.

Manual Reset

Press the blue reset button on the relay front. This is the most common method.

Automatic Reset

Some relays allow an auto-reset mode via a selector switch. Auto reset is useful for unattended systems but should be applied cautiously to avoid repeated tripping.

(If you’ve looked up “how to reset Siemens solid state relay overload assembly YouTube,” note that the same sequence applies to SIRIUS thermal models.)

Practical Tips for Reducing Relay Costs

There are ways to save when sourcing Siemens SIRIUS overload relays:

• Check frame compatibility: Match your relay with the correct Siemens SIRIUS 3RT contactor frame. Buying the pair together often lowers total cost.
• Leverage bulk discounts: Many suppliers (including Simply Buy) reduce unit prices when ordering multiple relays for projects.
• Consider service factor:  If your motor has a higher service factor, ensure the relay’s setting covers that margin. This prevents overspending on a larger relay than needed.
• Plan for accessories: Optional items like auxiliary contacts, remote reset modules, or manual/auto reset selectors add cost. Budgeting for these upfront avoids surprises later.
• Use updated catalogs: A Siemens thermal overload relay price list can shift with market conditions. Always refer to current listings or request a quote to lock in accurate pricing.

Sourcing Genuine Siemens Relays and Expert Support from Simply Buy

When comparing a Siemens thermal overload relay price list, factor in more than cost. Authenticity, manuals, and support matter too.

Simply Buy provides:

• 100% genuine Siemens SIRIUS overload relays.
• Direct links to Siemens SIRIUS overload relay manual and Siemens thermal overload relay manual for installation reference.
• Competitive pricing and bulk discounts on both thermal overload relay Siemens 3RU and electronic 3RB models.
• Expert guidance to help you choose between options (manual reset vs. automatic reset, bimetal vs. electronic).

By pairing pricing transparency with technical support, Simply Buy helps you choose and maintain the right overload relay with confidence.

Conclusion

After reading this guide, the next step is selecting the correct model for your motor’s current range and application. Review your motor’s FLA, consult the Siemens thermal overload relay manual, and use a Siemens overload relay wiring diagram to double-check your setup. With genuine products and expert support from Simply Buy, you can protect your motors with confidence.