• Max test current of 27A @ 550V test voltage & 20Ω
  • 16 to 400Hz operating frequencies
  • 300V CAT IV Phase to Earth & 550V Phase to Phase
    • 400V supply voltage at 16Hz
    • ±5% ±2V accuracy
  • Choice of 20 or 200Ω loop impedance
    • ±5% ±0.03Ω accuracy, 0.01Ω resolution (20Ω)
    • ±5% ±0.05Ω accuracy, 0.1Ω resolution (200Ω)
  • IP54 dust and water protection
  • Meets IEC61010-1, EN61557, & IEC61326-1

What's in the Box

  • Red/green 2-wire test lead set
  • Certificate of test
  • Hard carry case


The Megger LT300 high current loop tester uses two-wire operation and works over a wide range of frequencies and supply voltages. Loop testers are used to measure earth fault loop impedance and determine prospective fault currents.

The supply frequency is automatically determined upon connection. It will set the measured supply frequency to either 16, 50/60 or 400Hz which encompasses even more operating frequencies.

Please be aware that high current load loop testers used to be the norm but, with the introduction of RCDs on many circuits, the industry is moving toward lower test currents to prevent tripping during a loop test.