What Are The Advantages of Solid State Relays?

There are two main types of relays in the industrial sector — electromechanical and solid-state. Both have their place in the industrial sector. But solid-state relays are gaining popularity in industrial applications where electromechanical relays have traditionally been used.

So, what are solid-state relays and what advantages do they offer over other relay types? Our guide explains everything.

What Are Solid State Relays?

Relays are switches that control circuits’ opening and closing. The two main types are solid-state and electromechanical.

A solid-state relay (SSR) switches on and off when an external voltage is applied across the relay’s input terminals. Solid-state relays rely solely on electronic operation. There are no physically moving parts, which is why it is called a solid state.

An electromechanical relay (EMR) uses an electromagnetic coil that has a control signal applied to it to create an electromagnetic field. It has moving contacts, operated by applying an electrical signal. It operates via electrical and mechanical energy, which is why it is called electromechanical.

SSR vs EMR

• Solid-state relays use a low-power electrical signal to generate an optical semiconductor signal. This transmits the output signal. In other words, the input optical signal acts as the “switch” allowing a high-voltage signal to pass through the SSR’s output.

• Electromechanical relays use electromagnetic forces from an electromagnetic coil for the low-power input signal to generate movement of a physically moving part. And this mechanical part connects contacts in the output component.

Unlike electromechanical relays, which use magnetism and moving contacts, SSRs use semiconductors and optoelectronics to switch things on and off. It is the lack of moving parts that offers many of the advantages of solid-state relays.

5 Key Advantages of Solid State Relays

When constructing machinery and control panels, engineers and control panel builders carefully consider the advantages vs disadvantages of each component. This includes relay switches. When compared to electromechanical relays, solid-state relays offer five distinct advantages.

Shorter Response Times

Does your control equipment require very fast switching? A solid-state relay is the better choice because their lack of moving parts means much shorter response times. They can switch on and off much faster than relays that rely on physical moving parts.

Even if it seems minimal, these faster responses make all the difference in safety systems to prevent workplace incidents and equipment damage. When extra speed counts the most, SSRs are the way to go, for example as motor overload relays.

Reduced Wear and Tear

Moving parts inevitably suffer from wear and tear over time. This is an inescapable fact of industrial equipment and components. And it’s what control panel builders and engineers love about SSRs. Solid-state relays don’t have the moving parts other relays do.

This means they suffer less mechanical wear, and therefore offer greater reliability. There’s no more mechanical wear or contact failure to worry about. This means less to repair or replace over time, and therefore less downtime and expense. 

Less Sensitivity to Environmental Factors

Industrial sites are harsh environments, prone to constant wear and excessive noise and vibration. However, this is not a problem for the solid-state relay. Because it has no moving parts, SSRs are less sensitive to environmental factors.

A solid-state relay can continue operating despite magnetic fields or excessive vibration and shock. All the parts are electronic, and typically sealed. This contributes to the impressive longevity of electromechanical relays.

Quieter Operation

Electromagnetic interference (EMI), unwanted electrical noise in an electrical path caused by external factors, is a common problem in industry. It disrupts electronic operations, causes equipment to malfunction, and can even lead to complete equipment failure. But this problem is reduced with SSRs.

Solid State Relays use electronic circuits for switching, with minimal to no electromagnetic interference noise. This leads to two distinct benefits — significantly less EMI interference than electromechanical relays and quieter overall operation.

Greater Energy Conservation

Energy efficiency is becoming more and more important in the industrial sector. If you are looking for ways to conserve energy, you’ll be glad to know that SSRs meet this need, too. Solid-state relays require minimal power, even when handling higher power loads.

Solid-state relays use less energy than electromechanical relays, making them the best choice for dependable control while conserving energy. Your control systems will be much more efficient, and ideal for HVAC system automation and control.

Conclusion

The choice of which type of relays to use when constructing automation control panels is a very important one. Solid-state relays offer several crucial advantages over electromechanical relays, which increase equipment longevity and reliability.

Do you need dependable relays that offer quiet, dependable operation even in harsh environments? At AEC, we stock the relays/timers and other control components you need to keep your operations running smoothly. Contact us for all your electrical automation and control needs.