A power system fault can be cleared in less than a tenth of a second. Yet a slow trip circuit can turn that brief event into months of repair work. That is exactly why the Hitachi RXMB High Speed Relay earns its place in modern protection schemes.
The Hitachi RXMB Auxiliary Relay is a fast-acting relay that repeats and multiplies protection signals. It switches trip and control circuits within milliseconds. Engineers use it to send quick trip commands and isolate faults before equipment suffers damage. Furthermore, it comes in many contact and coil versions for AC and DC systems.
This guide explains where RXMB relays fit, how they work, and how to choose one. As a supplier of Hitachi auxiliary relays in India, DSG Enterprises Ltd answers these questions every day. We also cover the factors behind the Hitachi RXMB Relay Price, because buyers ask about it first.
What Is the Hitachi RXMB Auxiliary Relay?
An auxiliary relay receives signals from a protection relay and operates the required contacts. The Hitachi RXMB Auxiliary Relay supports fast switching and flexible configurations for protection panels.
Think of the protection relay as the brain and the auxiliary relay as the muscle. The protection relay detects the fault, while the auxiliary relay repeats the trip signal or operates additional circuits. This makes auxiliary relay selection important for reliable panel operation.
The RXMB family offers several useful features:
- Flexible Configurations: Multiple contact and coil options suit different panel requirements.
- High-Speed Operation: Supports applications requiring fast auxiliary tripping.
- Pin Compatibility: Compatible versions can simplify replacement of RXMA 2 relays.
- Compact Design: Selected configurations support multiple relay elements in one assembly.
- LED Indication: Available on selected versions for easier status monitoring.
- AC and DC Options: Availability depends on the specific model.
Always verify the exact model specifications, contact arrangement, and supply requirements before selecting a relay.
How Does the Hitachi RXMB High Speed Relay Work in a Trip Circuit?
Speed is critical in protection systems because delays can prolong fault current. In a 50 Hz system, one cycle lasts 20 milliseconds, so fast relay operation matters.
The Hitachi RXMB High Speed Relay helps reduce delays within the trip circuit by operating its contacts quickly after receiving a signal.
A typical trip sequence works as follows:
- The protection relay detects a fault.
- Its output contact sends a trip signal.
- The RXMB operates its contacts.
- A contact energises the circuit breaker trip coil.
- Other contacts activate alarms or related control functions.
- The relay resets according to its operating characteristics.
Multiple contacts allow one input signal to trigger several actions, supporting coordinated protection and control.
The RXMB 2 offers faster pick-up and drop-out than the RXMA 2, making it suitable for applications requiring rapid switching. Actual fault clearing time still depends on the protection relay, auxiliary relay, trip circuit, and circuit breaker performance.
Key Applications in Power System Protection
The RXMB series suits protection schemes requiring fast signal repetition and multiple contacts. It is used in substations, power plants, and industrial control panels. Compact configurations can also help panel builders save space.
Common applications include:
- Trip Auxiliary Duty: Repeating trip signals to associated control circuits.
- Contact Multiplication: Operating alarms, interlocks, and indicators from one input.
- Lockout and Backup Schemes: Supporting coordinated protection logic.
- Alarm and Annunciation: Sending status signals to indicators and control systems.
- Control and Relay Panels: Combining multiple relay elements in compact assemblies.
- Panel Upgrades: Pin-compatible versions can simplify replacement of older relays.
Substations and Utilities
Utilities use auxiliary relays to repeat trip signals from line, transformer, and busbar protection schemes. The RXMB supports coordinated breaker tripping and related control functions. Its compact configurations can help simplify panel layouts.
Power Plants and Industry
The Hitachi RXMB Auxiliary Relay supports generator, transformer, and motor feeder control circuits. The Hitachi RXMB High Speed Relay is suitable for applications requiring rapid contact operation. Selected versions include LED indicators for easier status checks.
Retrofits and Upgrades
Compatible RXMB versions can replace certain older RXMA and RXMM relays. Confirm the exact model and pin arrangement before upgrading to minimise wiring changes and installation time.
Overall, the RXMB provides a flexible option for auxiliary switching in protection and control systems.
RXMB 1 and RXMB 2: Choosing the Right Version
Select the appropriate version based on contact requirements, operating speed, and available panel space.
RXMB 1: Compact and Versatile
The RXMB 1 supports general auxiliary relay applications and is pin-compatible with the RXMA 1 and RXMM 1 in compatible configurations. It offers different contact and coil arrangements, with LED indication available on selected versions.
RXMB 2: More Contacts and Faster Operation
The RXMB 2 builds on the RXMB 1 with additional contacts and faster pick-up and drop-out than the RXMA 2. Available configurations include up to 15 contacts or 10 change-over contacts. Some assemblies contain four independent relays, each with two change-over contacts.
A change-over contact switches between two circuit paths, supporting flexible control arrangements. Verify the contact layout and compatibility of the selected model before replacement.
Before ordering a Hitachi RXMB Auxiliary Relay, check the following:
- Supply Requirements: Confirm coil voltage and AC or DC supply.
- Contact Count: Verify the required contacts and any spare capacity.
- Status Indication: Determine whether LED indication is needed.
- Model Compatibility: Check the existing relay type and pin arrangement.
- Operating Speed: Ensure the relay suits the protection scheme’s requirements.
Choosing a Hitachi RXMB Relay Supplier: Price and Support
Choosing the right Hitachi RXMB Relay Supplier helps ensure correct specifications, product documentation, and timely delivery. Before ordering, check these points:
- Product authenticity and supporting documentation.
- Guidance on contact and coil configurations.
- Quotation turnaround and delivery timelines across India.
- Support for compatible RXMA and RXMM replacements.
Request the datasheet and confirm the coil voltage and contact arrangement before placing an order. This helps reduce selection errors and commissioning delays.
The Hitachi RXMB Relay Price depends on several factors:
- Relay Version: RXMB 1 or RXMB 2.
- Configuration: Contact arrangement and coil specifications.
- Supply Rating: AC or DC requirements.
- Order Quantity: Number of units required.
- Availability: Current stock and delivery requirements.
Since pricing varies by configuration and availability, share your technical requirements with the supplier for an accurate quotation. For bulk orders, compare pricing, delivery schedules, and technical support before making a decision.
Frequently Asked Questions
Q: What is the Hitachi RXMB used for?
The Hitachi RXMB is a high-speed auxiliary relay used in protection and control panels. It repeats trip signals and multiplies contacts for breaker tripping, alarms, and interlocking. The Hitachi RXMB High Speed Relay suits applications in substations, power plants, and industrial facilities.
Q: What is the difference between RXMB 1 and RXMB 2?
The RXMB 1 supports general auxiliary switching and is compatible with certain RXMA 1 and RXMM 1 versions. The RXMB 2 offers additional contacts and faster pick-up and drop-out than the RXMA 2. Available configurations vary by model.
Q: Does the RXMB come in AC and DC versions?
Yes, AC and DC versions are available for selected RXMB models. Coil options and LED indication depend on the version. Confirm the supply voltage and contact arrangement before ordering a Hitachi RXMB Auxiliary Relay.
Q: How do I find a reliable supplier in India?
Choose a Hitachi RXMB Relay Supplier that provides product documentation, clear specifications, and technical support. Request a written quotation confirming the relay model, coil rating, contact configuration, and delivery timeline.
Conclusion
The Hitachi RXMB High Speed Relay gives protection engineers fast, flexible, and space-saving switching. Because the Hitachi RXMB Auxiliary Relay repeats signals quickly, it shortens the path from fault to breaker trip. It also multiplies contacts for alarms and interlocks. Furthermore, the RXMB 1 and RXMB 2 versions cover everything from compact panels to contact-heavy schemes.
Looking to buy the Hitachi RXMB Relay for your protection panel requirements? Contact DSG Enterprises Ltd to check availability and request a competitive quotation based on your specifications. Visit the Hitachi RXMB product page for product details. Call +91 7021624024 or email info@dsgeneterprises.in to discuss your requirements and get a quote today.
