Understanding how to connect solid-state relays is important, but understanding their applications is equally crucial.
By understanding their applications, we can know in which situations and how to best use them.
In this blog post, we’ll list 10 application areas for solid-state relays, including: temperature control, food and packaging equipment, smart homes, motor start/stop, and more.
1. Industrial heating temperature control system
Unlike the control of compressors in cooling systems (remember, frequent starting and stopping of compressors will greatly shorten their lifespan because, like motors, compressors have very high starting current, and frequent starting will cause the coils to overheat and burn out the compressor), the PID temperature controller in a precision heating temperature control system frequently activates and deactivates the controlled heating element to maintain a precise temperature.
Because of fast response time and short switching time of the solid-state relays, they are a perfect choice and thus widely used in the industrial heating temperature control system, such as HVAC, heaters.
2.Food and packaging automation equipment
Maintaining the right temperature is crucial in food production.
For example, high temperatures are used for sterilization to extend shelf life; and in the baking industry, precise temperature control makes bread more delicious.
In these industries, temperature controllers use actuators such as solid-state relays to control heaters, ensuring the required temperature is maintained.
Solid-state relays are also frequently used in packaging equipment, such as in heat-sealing or shrink packaging processes that require stable and precise heating to ensure packaging quality.
3.Smart home
Noise is an important factor to consider in the electrical design of smart homes.
Many electromagnetic contactors generate considerable noise when closed, which is why they are rarely seen in smart homes.
Relying on no noise characteristic of the solid-state relays can be used in smart home intelligent lighting systems, home electric heating, smart sockets, disinfection cabinets, and electric water heaters.
4.Motor start/stop and soft start
To be honest, AC contactors are more widely used for starting and stopping motors, but if you want to use alternative products to replace AC contactors, it is recommended to use solid-state relays.
In some special applications, such as flammable and explosive gas stations, it is more preferable to use single-phase or three-phase solid-state relays to control motors.
Another application of solid-state voltage regulators (a type of solid-state relay) is the soft starting of AC asynchronous motors. As the control signal increases or decreases, the solid-state voltage regulator can correspondingly increase or decrease its output voltage, making it an economical option for motor soft starting.
5.Medical and precision testing instruments
Solid-state relays can be used for temperature control in medical incubators, biochemical analyzers, physiotherapy heating equipment, and laboratory testing instruments. Their extremely low electromagnetic interference and non-contact nature ensures no interference with precision detection signals.
Medical and precision testing instruments require more reliable switching devices to ensure high reliability, and solid-state relays, with their high switching speed, noiseless operation, and long lifespan of 5-10 years, are the optimal choice.
6.Stage lighting and audiovisual equipment control
Another important application of solid-state relays is in the control of stage lighting and audiovisual equipment.
By using 3-32VDC control signals from PLCs, Arduinos, and Raspberry processors, you can instantly and silently turn 1000W or 2000W LEDs on or off.
Furthermore, due to the absence of electromagnetic interference, solid-state relays can also be used in audiovisual equipment that is highly sensitive to electromagnetic interference.
7.Flammable and explosive chemical explosion-proof scenarios
Solid-state relays are widely used in explosion-proof environments with flammable and explosive chemicals, such as petrochemical workshops, dusty environments, and flammable and explosive gas environments, for controlling pumps, valves, heating devices, explosion-proof fans, etc.
Solid-state relays feature fully sealed, non-contact, and spark-free switching characteristics, eliminating ignition sources at the source.
With explosion-proof housings, solid-state relays meet relevant explosion-proof requirements, and their intrinsic safety performance is superior to that of traditional contactors.
8.CNC machine tools and production line automation
CNC(Computer Numerical Control) machines are widely used in metal processing production.
They consist of 6 parts: control system, motion drive system, structural components, machining elements, sensing feedback system, and cooling and lubrication system.
Solid-state relays can be used in the cooling and lubrication systems of CNC machine tools to control cooling pumps, hydraulic solenoid valves, workstation indicator lights, fixture cylinders, etc., and can be directly driven by PLC in the control system section.
9.Photovoltaic and new energy DC systems
In off-grid solar power systems, solar panels generate direct current (DC), which is then stored in lithium-ion or lead-acid batteries via pulse-width modulation (PWM) or maximum power point tracking (MPPT) solar charge controllers.
In this DC solar power system, the battery management system (BMS) can use DC-controlled solid-state relays (SSRs) to control the switching of the DC energy storage system. Alternatively, we can also use DC/AC SSRs in the inverter section to control the switching of the load’s AC power supply.
10.Signal switching and data acquisition system
In some applications, solid-state relay modules can replace EMR modules in signal switching and data acquisition systems.
A product image of the module is shown below:
These solid-state relay modules can be single-channel, dual-channel, quad-channel, eight-channel, etc.
By receiving control signals from a PLC or other compressors, they can control individual loads subsequently.
For example, in an automatic sealing machine, the first channel controls the motor’s start and stop, the second channel controls the solenoid valve’s on/off state, the third channel controls heating, and the fourth channel controls the shearing action.
Conclusion
In summary, solid-state relays are not only used in the 10 applications mentioned above, but also in many other applications not mentioned here.
If you are looking for a reliable solid-state relay supplier to meet your specific application needs and would like to receive free technical support, you can send your inquiry to shonxu@lorentzzi.com, and Lorentzzi® Electric staff will be happy to assist you.
