7.1.2. L-N or L-L circuits
L1
N
E
L-N (or L-L) selected Test performed
Test options in L-N (L-L) mode
In L-N (L-L) mode the MFT1800 series offers one type of loop test:
2Hi – A 2-wire high current test. A fast 3-4 second test using high test currents.
Where to use:
On ALL circuits except Phase – Earth measurements on RCD protected circuits.
7.1.3. Z, Zmax, Zref and R1+R2 (MFT1721)
The right range knob has additional options.
Z - Standard loop impedance measurements
Zmax - For multiple loop measurements where the worst case value is required
Zref - the Ze or Zdb value used when calculating the R1+R2 value
R1+R2 - The loop impedance less the Zref value.
For general loop impedance testing the Z setting should be selected.
Refer to section 7.5 to 7.7 for additional functionality.
7.2 Making a loop impedance measurement
7.2.1. Ze measurements at the origin (Phase to Earth)
1. Set the LEFT rotary range knob to the
L-PE
range.
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MFT1800 series
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Loop impedance testing
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