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Appliances Can Kill... Safety First!
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Electrical Terminology
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Number Prefixes
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Ohms Law
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An overview of our safe working practices
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What is Earth Loop Testing
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TN-S Earth System
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TN-C-S System
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TT System
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Testing a TN-S Earth System
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Testing a TN-C-S System
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Testing a TT System
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How to perform an earth loop test from a hard wired appliance
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What is Earth Continuity
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Earth Continuity Test Sequence
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What is Insulation Resistance?
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Insulation Resistance Test Sequence
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How to test Earth Continuity and Insulation resistance on a freestanding appliance.
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How to test Earth Continuity and Insulation resistance on a hard wired appliance.
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Safe Isolation
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Water Regulations
Quizzes
Prefixes are commonly used in conjunction with electrical terminology. Most modern ‘Auto-ranging’ test equipment will also convert test readings into prefixes.
For example, when testing a Temperature Sensor (NTC) at 20 degrees we can expect the multimeter to show a reading of 6.05KΩ, this is 6050Ω
So it is very important to understand what the number prefixes are as-well as the electrical terminology.
These prefixes can commonly be found stamped on components, this can help to identify what test reading can be expected. Some test equipment will auto range and automatically show the prefix but some won’t.
When carrying out an insulation resistance test on the element pictured to the left. We get a reading of 0.127MΩ. Without the prefix, this is 127000 ohms.
The tumble dryer capacitor pictured to the right is labeled as 8µF. That is 8 microfarads. When testing this could also be displayed as 0.000008 farads.
