Info!! Ability Furnish Leakage Electrical Flow Testing To Iec60990

A client of late asked me why nosotros specify leakage electrical flow on a Class II ability supply, when a Class II ability furnish has no terra firma terminal.  Influenza A virus subtype H5N1 expert question, but offset simply about background.

As role of the testing for IEC60950, ability furnish manufacturers mensurate leakage electrical flow to the IEC60990 standard.

To locomote to a greater extent than accurate, the damage "Touch Current" in addition to "Protective Conductor Current" supervene upon the term "Leakage Current".

Protective Conductor Current (PCC)

Is the electrical flow that flows through the protective conductor; commonly referred to every bit the terra firma connection.

As a note, the withstand voltage in addition to insulation resistance tests mensurate the electrical flow flowing through the insulation of the unit of measurement nether test.

 Touch Current (TC)
Is the electrical flow that flows when a human trunk touches the equipment, faux past times a trunk impedance network.

The switches are used to copy a line, neutral or terra firma fault, referred to every bit a unmarried mistake status (S.F.C.).  Usually in that place is a polarity reversal switch to opposite the work in addition to neutral connections to the ability supply.

So dorsum to the master copy client question, if a Class II ability furnish is used, in that place volition locomote electrical flow that flows through a human trunk upon touching conductive parts inwards a organization (like a USB port or a conductive production case).  That measured electrical flow is ordinarily listed on the ability furnish datasheet.

Here is an excerpt from a CB written report showing the test, input voltage, frequency in addition to the measured ship on current.  Note one-half the tests conducted were alongside the faux human trunk touching the “output connector” or pins of the ability supply. 

Enclosure leakage electrical flow (normal conditions, normal polarity)	264 V	63 Hz	5,3 µA
Enclosure leakage electrical flow (normal conditions, opposite polarity)	264 V	63 Hz	4,1 µA
Enclosure leakage electrical flow measured on output connector (normal conditions, normal polarity)	264 V	63 Hz	89,0 µA
Enclosure leakage electrical flow measured on output connector (normal conditions, opposite polarity)	264 V	63 Hz	87,0 µA
Enclosure leakage electrical flow (single mistake conditions, neutral open, normal polarity)	264 V	63 Hz	4,1 µA
Enclosure leakage electrical flow (single mistake conditions, neutral open, opposite polarity)	264 V	63 Hz	6,0 µA
Enclosure leakage electrical flow measured on output connector (single mistake conditions, neutral open, normal polarity)	264 V	63 Hz	3,0 µA
Enclosure leakage electrical flow measured on output connector (single mistake conditions, neutral open, opposite polarity)	264 V	63 Hz	129,0 µA

The ammeter used is a specialized meter; create non utilisation a regular hand-held multi-meter!

For to a greater extent than details, including the limits of the measured currents, delight consult a professional person security engineer.

Get the product brochure from TDK-Lambda Americas for production descriptions.