Leakage current testers

Leakage current testers are used to verify the electrical safety of devices and systems in accordance with standards. The leakage current refers to the current that flows through the insulation or via capacitive coupling from live parts to grounded parts or to the enclosure. To to ensure the safety of people and equipment, this current must not exceed certain limit values.

The leakage current tester applies a defined operating voltage to the device under test and measures the current that flows through the protective earth conductor or non-conductive parts.

Measurements are performed in accordance with relevant standards, such as:

• DIN EN 60601 (Medical Technology)
• DIN EN 60335 (Household Appliances)
• DIN EN 60950 / 62368 (IT and audio/video equipment)
• UL regulations
• etc.

leakage current test involves determining the amount of current that flows from the current-carrying conductors to the e protective earth conductor , or to parts of the enclosure due to insulation failure and/or design-related factors. Various testing standards (e.g., VDE, EN, IEC, UL, etc.) require the measurement and evaluation of leakage current.

Why the " leakage current test " is so important.

Electrical appliances can only be operated safely if they have a high level of electrical insulation resistance. In the worst-case scenario, poor insulation can lead to electrical accidents resulting in serious injury or even death.

The electrical product is typically tested using a TEST VOLTAGE that is set at a percentage value specified in the standard above the product's nominal voltage . This value is often 1.1 times the nominal voltage.

What types of " leakage current test " are there?

leakage current s can be measured in two ways:

The " device under test " is in function

• • The standard refers to Procedure A
  • This method is also known as “Warmleakage current test.”
  • TEST VOLTAGE is supplied with single-phase power between the device under test L and N terminals.
    • There are two options for feeding power into the grid:
      • A1: L to phase – N to neutral
      • A2: N to phase – L to neutral

• • TEST VOLTAGE is supplied in three phases via the device under test connections L1, L2, L3, and N.
    • There are four ways to feed power into the grid:
      • L1, L2, L3, N / Normal state
      • open, L2, L3, N / fault condition
      • L1, open, L3, N / fault condition
      • L1, L2, open, N / fault condition

" device under test " is not in function

• • The standard refers to Procedure B
  • This method is also known as “Cold leakage current test.”
  • TEST VOLTAGE is fed between the bridged device under test terminals L and N to the PE.

What are some typical standards?

Globally, two standards are of central importance in Europe:

EN 60990 – Methods for measuring touch current and protective conductor current

• • Touch current on accessible metal parts of the test object
  • leakage current in the test object's " protective earth conductor "

EN 60601 – Methods for measuring leakage currents in medical devices and systems

• • Touch current on accessible metal parts of the test object
  • leakage current in the test object's " protective earth conductor "
  • leakage current on patient ports, etc.
  • Various types of patient leakage currents under a wide range of fault conditions
  • Various types of patient assistance currents under a wide range of fault conditions
  • Measurement of leakage current with frequency components up to 1 MHz

SCHLEICH offers the appropriate testing equipment for all European and global standards, such as UL, and their respective applications.

What are the "good/bad" criteria?

leakage current test 's performance is always evaluated based on the current level. It must not exceed a configurable limit.

What is an MD?

The MD (Measurement Device) is a measurement circuit consisting of resistors and capacitors used to determine the leakage current. In principle, it simulates the person at risk through whom the leakage current would flow in the event of a fault.

The standards list various MD variants. All of these variants can be integrated into a SCHLEICH leakage current tester.

What is the " substitute leakage current test"?

substitute leakage current test is a cold leakage current test using Method B, but with a reduced TEST VOLTAGE of, for example, 40 V AC. The current flowing during this process is then extrapolated in proportion to the current that would flow at 110% nominal voltage .

Here's how to find the right leakage current tester.

If you only want to use the leakage current test on your device under test run , a single-unit tester is the right choice. However, this unit already includes two test methods: the function test and the leakage current test.
The function test is required to operate the device under test according to methods A1/A2 at voltage .

If the device under test also requires a more comprehensive safety and functional check, we recommend our combination testers/multifunction testers. These allow you to conveniently combine various test methods—such as insulation, high-voltage, and protective earth resistance test —in a single device . The test method selection feature in the device ensures that no test leads need to be manually reconnected to the device under test during the test.

Thanks to the intuitive and user-friendly operation of our leakage current testers, every test is performed quickly, accurately, and cost-effectively.