test method
protective conductor resistance
What is protective conductor resistance why is it tested?
The protective conductor test used for devices in protection class I. It checks whether the protective conductor resistance is protective conductor resistance the limit values defined in the relevant standards. Only a protective earth conductor with sufficiently low resistance protective earth conductor safely dissipate dangerous voltages in the event of a fault and thus reliably protect people.
What risks are identified by the audit?
A functioning protective conductor connection is essential in order to:
- Safely discharge leakage currents to earth so that no increased touch voltage occurs on metal housing parts.
- Discharge dangerous fault currents in a short-circuit-proof manner, for example, if the insulation in device deteriorates device operation and a housing short circuit occurs.
- In the event of a fault, the fuse must be triggered to ensure that a sufficiently high short-circuit current protective earth conductor through the protective earth conductor
How is protective conductor resistance ?
For measurement purposes, a Test current defined in accordance with standards is protective earth conductor Test current the protective earth conductor . The following applies:
- The Test current usually at least 1.5 × the rated current of the device. Details can be found in the relevant device standard for your product.
- Typical test currents space 10 space 32 A, and in some cases higher in the USA and Canada. SCHLEICH test equipment with test currents above 100 A AC/DC. These high test currents are used less in production and more in laboratories and certification institutes for type testing.
- The protective conductor resistance Test current protective conductor resistance from the voltage drop generated and the known Test current .
To keep the measurement accurate regardless of the cable length, four-wire technology Kelvin measurement) is used:
Two conductors carry the Test current, while two others measurement voltage drop directly at the test point.
Practical implementation of the PE exam
The test is often performed using a manual protective conductor test probe at several test points on the test object. For more complex or serial test tasks, fully automatic systems with relay matrices can also be used. These enable:
- Testing of numerous PE points without manual reconnecting
- Flexible configurations ranging from "one point against PE" to "everyone against everyone" matrix methods.
Easy switch-over to Test from different test points against a central test point, e.g., the PE.
four-wire for Test between any test points according to the "everyone against everyone" method.
-
Manual, semi-automatic, and fully automatic testing devices
-
Systems with relay switching panels for testing at multiple PE points
-
four-wirefor maximum precision
standards bodies
For legal reasons, we are often unable to make any binding statements regarding test conditions. The currently valid standards for the product to be tested are decisive for its application.
The standard may vary depending on the geographical location where the product is used. Further information can also be found at the institutes listed below.
