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Application note for Zref and R1+R2 measurement:
On
initial verification
of a new electrical installation, the value for R1+R2 should be obtained by continuity
testing methods (dead testing) as per BS 7671:2001 or other international standards.
For periodic inspection reports (PIR) where it is not possible to isolate the supply, the user should first verify the
Circuit Protective Conductor (standard practice) prior to using the Zref and R1+R2 function on the instrument.
Prior to measuring Zref, all main equipotential bonding must be in place.
Note: Measurements made on live installations by this method may be lower than the Ze + (R1+R2) from those
obtained by continuity testing methods, due the existence of parallel earth return paths from extraneous
conductive parts.
To make use of the R1+R2 test feature, the reference/distribution board (Ze or Zdb) result must be stored in the
instrument’s memory (Zref), prior to measuring R
1
+ R
2.
5.8.1 Measuring Zref
1.
Switch the top range knob to [Zref]. The display will show the [
] symbol to indicate a Zref test mode
is selected.
2.
Select any loop test range as appropriate.
3.
Connect the instrument to the circuit under test as described in section 5.2, 5.3 or 5.4 as required.
4.
Press the [TEST] button to perform a loop test. The test result is displayed and stored internally as Zref.
5.8.2 Measuring R1+R2
5.
Switch the top range knob to the [R1+R2] range. The display will show the [
] symbol to indicate
an R1+R2 test mode is selected.
6.
All subsequent loop test measurements will have the Zref resistance subtracted.
7.
To view the stored value of Zref press the PFC key, press the PFC again to return to the R1+R2 value.
8.
If measured value of R1+R2 is less than zero, the display will show the measured value of R1+R2 for 2
seconds, then the error message [
] will be displayed to indicate such error. In which case repeat the
R1+R2 measurement. If the error persists, repeat with a new Zref measurement followed by R1+R2.
If a Zref measurement was not made prior to an R1+R2 test, an R1+R2 test will not be performed, and the
warning [
] will be displayed for 2 seconds.
6. Voltage and frequency measurement
WARNING: The instrument must not be used on CATII, CATIII or CATIV systems with voltages
greater than 300V phase to earth and 440V Phase to Phase.
6.1 Phase to Earth and Phase to Neutral voltage and frequency measurement
To measure the voltage of the electrical supply using the mains socket test lead:
1.
Set the instrument to the [V/Hz] range.
2.
Connect the
RED
plug of the mains socket test lead to the instrument.
3.
Connect the
GREEN
plug of the mains socket test lead to the instrument.
4.
Insert the plug into the mains outlet socket.
5.
The instrument will display the voltage and the frequency.
To measure the Phase-Neutral voltage, connect the
RED
and
BLUE
plug of the mains socket test lead to the
instrument.
To measure the voltage of the electrical supply using the RED/GREEN test leads:
1.
Set the instrument to the [V/Hz] range.
2.
Connect the
GREEN
test lead to the Protective Earth (PE) and the
RED
test lead to the phase to be
measured.
3.
The instrument will display the voltage and the frequency.
