Why do we use 24V circuit control (PLC and relay system) instead of 5V?
The 24V control circuit is the industry standard because it offers superior noise immunity, long-distance signal transmission, dependable switching, and interoperability with industrial devices while staying safe for human use.
Using 24V control circuits in PLC and relay systems instead of 5V is widely used because of the following advantages:
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Compared to lower voltage signals like 5V, higher voltage signals (24V) are less vulnerable to electrical noise and interference.
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Electrical noise is frequently produced by motors, VFDs, and other high-power equipment found in industrial settings. Unreliable functioning could result from the easy manipulation of a 5V signal.
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Much greater distances can be covered with a 24V control signal without experiencing noticeable interference or voltage drop.
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5V signals need more buffering because they are weaker and can deteriorate over long the cables.
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The majority of industrial actuators, relays, and sensors are made to run on 24V.
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24V DC is frequently used as the control voltage for contactors, solenoids, and PLCs.
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Compatibility is made easier and less additional voltage conversion is required when 24V is used.
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Relays and PLC inputs and outputs operate more dependably when signals with higher voltage are present.
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In order to prevent oxidation and poor conductivity, contacts in relays and switches need a minimum voltage and current.
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It’s possible that 5V signals won’t produce enough energy to turn industrial relays consistently.
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Although 24V DC is far more dependable than 5V, it is still regarded as a safe level for human interaction.
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Unintentional voltage drops are more likely to occur with 5V control systems, which can lead to failures.
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A balance between dependability and safety is offered by 24V.
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For optimum operation, many industrial solenoids, pneumatic valves, and contactors need at least 12V or 24V.
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It would be more difficult to control certain kinds of equipment directly if 5V was used.
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Voltage × Current (P = V × I) equals power.
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We can obtain the same power at one-fifth of the current if we utilize 24V rather than 5V.
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Reduced power losses, thinner cables, and less heat dissipation are all results of lower current.
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24V DC is the standard for industrial control systems and PLCs because it guarantees dependability, security, and interoperability with sensors, actuators, and other devices.
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24V DC is readily supported by the majority of industrial power supply and batteries.
Why not use 5V?
- Susceptible to interference and noise.
- Restricted distance for transmission.
- Increased chance of voltage dips and erratic relay switching.
- Not compatible with a large number of industrial actuators and sensors.