Solid State Relays have been the standard in switching technology since the early 70's due to their high switching frequency, resistance to shock and vibration and superior lifetime.
Long Life Reliability
When properly used, a Solid State Relay (SSR) provides a high degree of reliability, long life and reduced electromagnetic interference (EMI), together with fast response and high vibration resistance, as compared to an electromechanical relay (EMR). An SSR offers all the inherent advantages of solid state circuitry, including consistency of operation and a typically longer usable lifetime. This is possible because the SSR has no moving parts to wear out or arcing contacts to deteriorate, which are primary causes of failure of an electromechanical relay. When properly applied, an SSR will have a normal life expectancy of many millions of operations, 10–1000 times more than most electromechanical relays. SSRs also have environmental advantages compared to mercury contactors.
Solid state relays can switch up to 120 times per second, much faster than any electromechanical relay. When used in heating applications, fast cycling can dramatically improve the life of the heater by reducing thermal stress.
Low Input Power Required
SSRs allow the switching of large loads via ultra-sensitive input power. A low level logic signal (TTL) can activate a switch for as much as 125 Amps.
Completely quiet switching, beneficial in medical applications, environmental controls or other areas where quiet operation is desirable. Zero-crossing control also means low electrical noise when used near computers, PLC™s, SCADA systems, or other factory automation control systems.
Eurotherm by Schneider-Electric is an industry leader in product innovation. We were the first company in the U.S. to produce and market a fully integrated DIN Rail mountable solid state relay with heat sink. We have proven that leadership again with the introduction of the Zelio family of SSRs.