IEC 60335-1 leakage current measurement

EMengineer

Starting to get Involved
#1
Good day,

I have worked with IEC 60601-1 and IEC 60950-1 standards and there leakage current measurement principle was to measure current between appliance (enclosure, patient connections, etc.) and earth (simulate if human touches any part).
Recently I started to study IEC 60335-1 household appliances and there's leakage current measurement - but it slightly differs from mentioned above. The principle of current measurement is to measure it between one phase and enclosure. But what will I find when I measure current between primary circuit and enclosure? What is the main purpose/ idea of such measurement? As I understood during this measurement the earth connection should be open.
Here is the diagram from the IEC 60335-1:
 

Marcelo Antunes

Addicted to standards
Staff member
Admin
#2
I have worked with IEC 60601-1 and IEC 60950-1 standards and there leakage current measurement principle was to measure current between appliance (enclosure, patient connections, etc.) and earth (simulate if human touches any part).
Not sure where you got this. Leakage current is always measured between a "non-live"part of the equipment (as you mentioned, enclosure, patient connections, etc.) and live parts (energized parts, not earth. If you measure between a "non-live"part and earth you will always measure zero (or near zero).

This test from 60335 is a measurement of touch current (or enclosure leakage current in old standards). The exact same measurement same measurement (with some different setups) exists in 60601 and 60950.
 

EMengineer

Starting to get Involved
#3
Thank you for your reply, I think I got confused with terminology. Does the leakage current mean the electric current which flows from parts at hazardous voltages to accessible parts, and touch current is the electric current which flows through human body when it touches one or more accessible parts?
Because in 60601-1 standard earth leakage current, patient and etc is measured between accessible parts and earth (example below):
 

Marcelo Antunes

Addicted to standards
Staff member
Admin
#4
Earth leakage current is not a problem in itself, it's only there so there's a limit to prevent a huge leakage flux in the installation. The measurement in itself does not simulate a common condition, because it would simulate the person touching the live pin in one side and earth at the other.

The problematic leakage currents are the one from the enclosure (touch current) and patient (patient leakage current). Please note that patient leakage only exists in medical electrical equipment. Other standards are worried only with touch (enclosure) current.
 

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