3RU21464MB0 | Thermal Overload Relay 80 – 100 A, Contactor Mounting, Auto/Manual Reset, Suitable For S3 Size Contactor – Siemens

Name: Siemens 3RU21464MB0 Thermal Overload Relay 80-100A
Brand: Siemens
SKU: 3RU21464MB0

SKU: 3RU21464MB0

Out of stock

20 People watching this product now!

Order protection

Buy with complete confidence.

We back each order with genuine supply, on-time dispatch and GST or commercial invoicing as required.

Buyer protection on every order

Global DeliveryShipped pan-India and to export markets.

On-Time DeliveryPacked and dispatched on schedule.

100% OriginalFrom brand-authorised channels only.

GST InvoiceCompliant, ITC-ready tax invoice.

Secure PaymentEncrypted, trusted payment gateways.

Also included Dedicated account manager Technical support Bulk & business pricing 3-day replacement

📋 Technical Specifications

Parameter	Value
Brand	Siemens
Part Number / SKU	3RU21464MB0
Category	Overload Relay
Current Rating	80–100 A
Standard	IEC 60947-4-1 / IS 13947-4-1
Certifications	BIS certified, CE, cULus (select models)

⚡ Key Features

Adjustable current range 80–100 A — set to the motor nameplate FLC for accurate overload detection; range covers multiple motor sizes from a single relay model.
Bimetal thermal element with phase-loss sensitivity — independently monitors each phase; trips if any phase carries more than ~115% of the set current, or on complete phase failure.
Normally open (NO) and normally closed (NC) auxiliary contacts built in — NO contact wired to motor run indicator; NC contact wired to PLC fault input or motor starter stop circuit.
Manual/automatic reset selectable — set to manual for attended machinery requiring operator acknowledgement; auto-reset for unattended remote installations.
Manufactured to IEC 60947-4-1 / IS 13947-4-1 — complies with the applicable Indian BIS and IEC international standards for this product category.
BIS certified, CE, cULus (select models) — meets Indian regulatory requirements for use in government, commercial, and industrial electrical installations.
Genuine authorised Siemens product — sourced directly from the official distribution network with full manufacturer traceability and warranty.
GST invoice provided for India orders — valid for corporate procurement, government project orders, and public tender supply via myelectric.in.
Worldwide export available — UAE, Singapore, UK, USA, Sri Lanka & more. Contact +91 94814 00316 for bulk pricing and international shipping.

❓ Frequently Asked Questions

Q: How do I set the 80–100 A adjustable range on the 3RU21464MB0 for my motor?

A: Turn the setting dial to the motor’s nameplate full-load current (FLC) — the FLC must fall within the 80–100 A range of this device. Setting it at the motor FLC (not the maximum of the range) gives correct overload trip timing while still riding through normal starting inrush. If the motor FLC is outside this range, select the adjacent rating in the same series.

Q: Does the 3RU21464MB0 provide single-phase (phase loss) protection?

A: Siemens thermal overload relays include single-phase sensitivity: if one phase is lost, the remaining phases carry higher current, causing the bimetal to heat and trip within the specified time. For critical motors, add a dedicated phase-loss relay for faster response independent of load — overload relay phase-loss protection is load-dependent and may take minutes to trip at light load.

Q: How do I set the 3RU21464MB0 to protect a motor without causing nuisance trips on starting?

A: Set the thermal overload dial to the motor’s nameplate full-load current (FLC) — ensure the FLC is within the 80–100 A range of this relay. For star-delta starters, set the overload relay to 58% of motor FLC (line current in delta = FLC × 0.58). Allow 10 trips for the relay’s thermal memory to stabilise before adjusting the setting.

Q: What is the difference between an Overload Relay and a standard MCB — and why use the 3RU21464MB0?

A: A standard MCB protects against overload and short-circuit only. An Overload Relay provides thermal overload protection calibrated to motor FLC, protecting the motor from sustained overloads that would destroy windings before a standard MCB trips. Choose the 3RU21464MB0 when the application specifically requires overload relay characteristics.

Customer Reviews

Rated 0 out of 5

0 reviews

Rated 5 out of 5

Rated 4 out of 5

Rated 3 out of 5

Rated 2 out of 5

Rated 1 out of 5

Reviews

Clear filters

There are no reviews yet.

Be the first to review “3RU21464MB0 | Thermal Overload Relay 80 – 100 A, Contactor Mounting, Auto/Manual Reset, Suitable For S3 Size Contactor – Siemens”