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Electromechanical Relays (EMRs) vs. Solid State Relays Comparison (SSRs)

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Electromechanical Relays (EMR) Pros (Advantages) Lower initial cost compared to solid state relays. Provides complete electrical isolation. Tolerates high current & voltage transients. Insensitive to electromagnetic interference (EMI) / radio frequency interference (RFI). Higher open resistance (air gap). Lower closed resistance. Available with many poles/circuits (up to 8 or more). Many different circuit configurations available. Multiple packaging & feature options. Most typical failure mode is open. Electromechanical Relays (EMR) Cons (Disadvantages) Higher control (coil) power consumption. Contact arcing can cause pitting & eventual open/short failure. Contacts can be affected by corrosion, oxidation or contamination. Contact bounce possible due to shock & vibration. Generates electromagnetic interference (EMI) / radio frequency interference (RFI). Can be orientation sensitive. Can be affected by external magnetic fields. Subject to mechanic

What is a solid-state relay (SSRs) / solid state contactor (SSCs)?

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A solid-state relay (SSR) or solid-state contactor (SSC) is an electronic component that switches power (AC or DC current) to a load circuit and provides electrical isolation between an application’s control circuit and load circuit. It is a competitive technology to electromechanical relays (EMRs) and other switching technologies such as mercury displacement relays (MDRs). Why use solid state switching technology? Long service life Quiet operation Minimum electrical noise Low power consumption Shock & vibration resistant Ideal for harsh environments High compatibility with control systems Reduced weight Position insensitive Fast switching Magnetic noise immunity Reduce energy cost Solid state relays & solid-state contactors applications Although there are literally thousands of individual uses for solid state relays and solid-state contactors, most can be categorized into the following applications: Heating control application This encompass