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How to choose a relay interface based on the needs of your application
October 2023

Why are relays important? Why is there such a wide variety of relays?

Relays have always been an integrated part of all forms of communication and power infrastructure, but with the increased usage of closed control systems in automated applications there has been a constant growth and change in the usage of relays. Over the years, all industrial components including relays have constantly changed to the following effect:


Relays have undergone constant miniaturisation based on two aspects. The fact that their usage has changed from just switching power circuits to being used as switches in communication circuits and hence a reduction in the ‘load’ or ‘power’ they need to switch. Also, changes in material science and manufacturing techniques have enabled the relays to be built smaller with better housings and contacts. As a matter of fact, in the case of electronic relays, there is no physical contact and coil mechanism to enable switching. The switching is conducted entirely through a semiconductor switch.

Improved Efficiency:

When it comes to relays in specific, they are now able to switch at far higher speeds and with minimum power loss. Semiconductor or Electronic relays of course have become the norm when it comes to extremely high switching rates.

Improved Life:

The number of operations that a relay can now undertake has also increased significantly on account of the fact that the relays are built with far superior materials and the fact that they need to switch much smaller loads. Also in case of electronic relays the expected life is extremely high as there is no physical switching involved.

With the above said there cannot exist a modern automation system without the use of relays and since each system may have its own specific need, the choice of relay becomes a critical function.


Parameters to consider while choosing a relay or relay interface

Below is a list of parameters that an engineer may consider in arriving at the exact choice of relay or relay interface:

  1. What is the primary need: isolation or switching?

  2. What are the isolation levels needed?

  3. What is the load value to be switched?

  4. What is the desired input voltage for the relay?

  5. What is the switching speed needed to support the application?

  6. Are their physical constraints in terms of the size of the relay or relay interface?

  7. What is life (MTBF) expected from the relay or relay interface?

  8. Will the maintenance or replacement of the relay or relay interface be easy?

  9. Will it be easy to expand/increase the number of relay channels needed?

  10. Do any of the relays need to be bussed at input or output?

  11. What type of relay failure indication is needed?

  12. Is there a need for specific signal conditioning on the input or output side of the relay interface to prevent any inadvertent functioning or premature failure of the relay interface?



Connectwell Relay Interfaces: Flawless Switching. Every Time. Everywhere

Connectwell offers a wide range of Relay Interfaces designed to cater to the diverse needs and standards of the power and automation industry. Connectwell Relay Interface Range is split into four product groups.

Connectwell Relay Interface Range

CIMRE Series Next-Generation Relay Boards - BUILT TO DELIVER VALUE

  • Fully enclosed IP20 design, ensuring a sleek and appealing appearance.
  • Compliance with  IEC60664 standards enhances safety measures.
  • UL-approved components enable continuous operation with a full contact rating.
  • 2,4 and 8 Channel Modules for up to 32 Channel Board Extension possibility.
  • Convenient jumpering with long tail jumpers for channel grouping.
  • 1CO and 2CO configurations, with electromechanical relays.



CRM Series High-Performance Relay Modules - BUILT TO LAST

  • True Modular Design with IP20 Safety Rating.
  • Superior flammability rating of V0 grade.
  • Continuous operation at the true full contact rating.
  • Superior quality, offering an increased operational lifespan.
  • Choice of voltage inputs with Electromechanical relays.
  • Attractive aesthetics with a consistent profile for 1CO, 2CO, and 4CO contacts.




CSR Series Compact Slim Relay Modules - BUILT TO SAVE PANEL SPACE

  • Save Panel Space: Up To 66% Saving.
  • True Modular Design with IP20 Safety Rating.
  • Compliance with CE and UL international standards.
  • Designed for continuous operation at the true full contact rating.
  • Choice of Electromechanical and Solid State Relays.
  • Attractive aesthetics with a consistent profile for 1CO and 2CO contacts.



IMRE Series Custom Relay Interfaces - BUILT JUST FOR YOU

  • Customizable design with high-quality components and industrial standards.
  • Choice of electromechanical and electronic relays with different contact types.
  • Various input and output connector options for easy connectivity.
  • Ability to incorporate electronic safety components based on application needs. 


To meet the wide-ranging needs of the modern power and automation industry one needs to consider a wide variety of parameters as listed above and only then arrive at the exact choice of relay or relay interface. Connectwell offers a wide variety of relay interfaces which can address most of the needs of the power and automation industry.


Connectwell, your right connection partner

With more than 15 international product certifications backed by the most stringent quality standards, our products pass through more than 40 quality assurance tests. This has ensured a ready acceptance of Connectwell terminal blocks across 80+ countries and in thousands of projects and applications worldwide.

Through our 4 decades of experience with state-of-the-art operations which are ISO certified, Connectwell has grown to become one of the leading manufacturers of terminal blocks in the world.

More than 1 million connections are made every day across the globe with Connectwell terminal blocks, making Connectwell a synonym for… the right connection.

So, if you would like to build your projects with a solution that can accommodate both dense and simple wiring, while saving panel space, ensure that you select Connectwell Multiple Level Terminal Blocks and get the added flexibility you need.

To know more about how Connectwell can contribute to your applications, please reach out to us at or +912517120600 / +912516762600


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