typical earth leakage values

[goasis]

hi all,

If there is such a thing as 'typical' values, what, in your experience would you consider these to be from equipment such as pc's and other IT, washing machines and any other significant sources?

thanks

 

[Vortigern]

3 ma per computer. Regs delineate what is acceptable as well. Of course you can measure each appliance of you wanted to know specific cases.

 

[Lucien Nunes]

3mA is at the high end of the range even for a PC, monitor and printer together; it's a sensible allowance for design purposes but I don't think I'ver ever actually registered as high as 3mA from any one consumer electronic product. Typical electronic goods tend to leak 0.1-0.5mA. I have to test some stuff tomorrow so I'll post the specific figures.

 

[Dartlec]

I believe there is a standard or technical document out there that lists expected values for equipment - it was mentioned in a recent E5 podcast I think, but I forget the name/number of it.

I think it's like most of the other standards - too expensive for most of the people who need it to ever get to see it

 

[pc1966]

Page 26 of the Schneider RCD guide CA908066E has a handy table:
https://download.schneider-electric.com/files?p_enDocType=Catalog&p_File_Name=CA908066E+(web).pdf&p_Doc_Ref=CA908066E

It lists a desktop PC at 2mA, printer at 1mA, portable computer (laptop I guess) at 0.5mA where it has a functional earth for EMC control.

It is a generally good guide to read, though obviously pushing their RCDs and telling us that type B is the dog's danglies for the future (not mentioning the price). Also it explains the reasons for "RCD uplift" in Zs measurements with a Fluke MFT on page 60.

 

[pc1966]

We used to see some stuff in the 3.5mA region at out work, but they had both inlet EMC filters as part of the IEC socket and also EMC filters in the internal PSUs, hence being about double the typical values seen.

 

[Wilko]

And just for fun - there is capacitance between L and E conductors in cables, so there is reactance at 50Hz as well. It’s not much, but I did have a go at measuring the capacitance just now and got 190pF/m (on 4m of 2.5/1.5 with my cheapo multimeter). If I’ve done my maths correctly this will give about 1.4mA leakage current in the CPC for each 100m roll used. Some time back I tried to measure this leakage directly with an earth leakage clamp meter and my best guess from that was about 1mA/100m in the real world.

Next question is - does an RCD even see leakage current with PF=0 ?

 

[static zap]

Page 26 of the Schneider RCD guide CA908066E has a handy table:
https://download.schneider-electric.com/files?p_enDocType=Catalog&p_File_Name=CA908066E+(web).pdf&p_Doc_Ref=CA908066E

That's a good document , it has some references to 10mA DC offset from
leaking Inverter supplies (Store high DC voltage relative to earth) ..
..Or why not to get them Wet--hence washing machine worries -Earth that box !

 

[hiren4776]

can some one help me with this problem?
I have one spike guard which has only neutral and line wires. but the sockets on the spike guard are 3 pin, the problem I am facing is that : I am getting current into my earthing line, I have got shocked many times from chargers, fridge surfaces, etc.
I am pretty sure that, there might be problem in the spike guard or in some device?