credit should be given
he uses a megger tester to check  the wiring

and i  havent  see  any wireman /electrician  carry/have  expensive test tools to do a proper job.

haa...    you know  simple wiring  ??  really 
talk K only  !
tnb  supply  is 230V        ......    so we use 220 ...  where ?? 

and a megger tester  is for  insulation test  . 
since when a megger tester  measure mA  ?? 
Megger multimeter
The Megger insulation tester is a small, portable instrument that gives you a direct reading of insulation resistance in ohms or megohms. ... This method is non- destructive; that is, it does not cause deterioration of the insulation.