Earth clamp tester Kew 4200/4202 cannot be used for earth measurements in following situations.

• Single earth systems (isolated from the other earth systems) like in many TT systems.
• Earth systems on which large fault current (over 2A) flows (This current can be checked by AC current range of our Kew 4200/4202)
• Earth systems with earth resistance values larger than 1500Ω
• When earth resistance under test is smaller than the total earth resistance (very rare case).