"Earthing" of Signal circuits
Usually we talk about "protective earth" to mean <0.1 ohm. This very low resistance is necessary to carry fault currents.
However, in the context of sinking leakage currents in the order of 1mA, we don't need to worry about 0.1ohm. In a Class I device, most signal circuits are "earthed" in the sense that they can sink a few mA of leakage current. An impedance of the signal circuit to earth of even 10,000ohms (resistive or capacitive) is unlikely to cause any increase in the voltage of accessible parts.
This is still considered "protective earthing" but is a special case. Both 2nd and 3rd edition allow for this special case in the clause for earthing.
Usually we talk about "protective earth" to mean <0.1 ohm. This very low resistance is necessary to carry fault currents.
However, in the context of sinking leakage currents in the order of 1mA, we don't need to worry about 0.1ohm. In a Class I device, most signal circuits are "earthed" in the sense that they can sink a few mA of leakage current. An impedance of the signal circuit to earth of even 10,000ohms (resistive or capacitive) is unlikely to cause any increase in the voltage of accessible parts.
This is still considered "protective earthing" but is a special case. Both 2nd and 3rd edition allow for this special case in the clause for earthing.
The rationale described in the annex A for 8.6.4b) seems not the case which mentioned above.