Operation Manual

14 GMC-I Messtechnik GmbH

Protective Conductor Resistance

Applications

Continuity and resistance of the protective conductor must be

measured.

Definition

Protective conductor resistance is the resistance of the

connection of a protection class I device (PC1) between any

exposed conductive parts which are connected to the protective

conductor and the protective contact at the mains plug or the

mains side of the permanent connection.

Protective conductor resistance is the sum of the following

resistances:

• Connector cable or device connector cable resistance

• Contact resistance of the plug and terminal connections

• Resistance of the extension cable

Measuring Method

Resistance is measured:

• Between each exposed conductive part of the housing which

is connected to the protective conductor (probe contact) and

the earthing contacts at the mains and the device plug (if a

removable mains connector cable is used).

• Between the earthing contacts at the mains plug and the

earthing contacts at the device plug for device connector

cables

test socket connection

Note



The protective conductor of the test socket (which is not

connected with the protective conductor of the mains termi-

nal for this measurement) is permanently connected with

sockets 3 and 4 to which a second probe can be con-

nected.