Zs from board supplying another board

[Mark Wright]

Ok thanks, surprised if it actually uses 230v for the test and doesn't use a transformer.

but maybe people should think a bit more before just plugging there tester into a socket and letting whatever A.C voltage 15mA flow through the earth etc.

 

[Ian1981]

Ok thanks, surprised if it actually uses 230v for the test and doesn't use a transformer.

but maybe people should think a bit more before just plugging there tester into a socket and letting whatever A.C voltage 15mA flow through the earth etc.

There is no danger,If the meter detects that the voltage rise is above the meters setting, typically 50v to earth then your meter will abort the tests, so the danger is removed.

 

[Mark Wright]

There is no danger,If the meter detects that the voltage rise is above the meters setting, typically 50v to earth then your meter will abort the tests, so the danger is removed.

Even a low voltage it might not be a "Danger"
but a child touching a metal faceplate in a residential property while a break in the CPC during such test it's obviously not very good, you can say you shouldn't be touching this and that but like I say some people probably don't take any precautions and work out R1+R2 from Zs test without even thinking a Live Current is flowing through the CPC.

 

[Ian1981]

Even a low voltage it might not be a "Danger"
but a child touching a metal faceplate in a residential property while a break in the CPC during such test it's obviously not very good.

The meter will not let you carry out the test if the voltage to earth rises above 50v by a break in the continuity of a cpc connecting to any exposed conductive parts
If we are talking initial verification, then continuity of the cpc and the connection to earth of any exposed conductive parts should have been verified before any live testing as prescribed in part 6 of bs7671

 

[davesparks]

Ok thanks, surprised if it actually uses 230v for the test and doesn't use a transformer.

but maybe people should think a bit more before just plugging there tester into a socket and letting whatever A.C voltage 15mA flow through the earth etc.

How would you connect a transformer to be able to test the loop impedance of the supply at anything other than the supply voltage?