Guide to electrical symbols in industry

We would like to introduce to our customers some common acronyms (symbols) in industrial electricity for customers to easily read technical drawings as well as extract the volume of equipment. Where the following symbols add after the letter "R", it means that it is a protective relay device. Example: ELR is the leakage current protective relay.

• OC : (Over Current), Only electrical equipment with overcurrent protection function (PCT included)
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• UC : (Under Current), only electrical equipment with protective function lack electricity
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• EF : (Earth Fault), only electrical equipment with ground protection function (PCT included)
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• EL : (Earth Leakage), only electrical equipment with function of leakage current protection, anti shock (With ZCT)
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• PL : (Phase Loss, Phase Failure), Only electrical equipment that provides phase loss protection
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• PR : (Phase Reversal, Phase Sequence), only electrical equipment with phase-order (phase-out) protection
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• OV : (Over Voltage), only electrical equipment functions overvoltage protection (over voltage)
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• UV : (Under Voltage), only electrical equipment with protection functions lacking voltage (low voltage)
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• UBV : (UnBalance Voltage) Only electrical equipment has the function of voltage imbalance protection
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• UBC : (UnBalance Current) Only electrical devices that provide electrical current imbalance protection
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• OF : (Over Frequency) Only electrical equipment with over-frequency protection function
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• UF : (Under Frequency) only electrical equipment with protective function lacks frequency
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• MCT : (Metering Current Transformer) Variable current measurement
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• PCT : (Protection Current Transformer) Variable current protection
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• ZCT : (Zero sequence Current Transformer) Order line variable zero
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• CBCT : (Core Balance Current Transformer) Another way to call ZCT
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• OSC : (OSCilloscope) Oscilloscope, oscillation sign
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• DSO : (Digital Storage Oscilloscope)Digital oscilloscope, digital oscillation
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• FG : (Function Generator) Broadcast machine
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• PWS : (Power Supply) the source, supplies
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• DC : (Direct Current) direct current
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• AC : (Alternating Current) Alternating Current
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• KW : kilowatt capacity meter
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• KWH : kilowatt / hour power meter
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• A, V, Hz : current meter, voltage, frequency
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• AS, VS : Switching switches for current and voltage meters