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3.3 Using the EZ2500
3.3.1 Connection
It is recommended that testing is carried out, as far as it possible, on a circuit
where all appliances are disconnected. Ensure you have read the Precautions
(Section 3.1) before proceeding.
N
Plug the E-ZeTest EZ 2500 into the socket to be tested using the IEC lead
supplied.
N
Ensure the socket is switched on.
N
View the messages on the display.
If you are using the E-ZeTest EZ2500 with TL88 leads to test wiring, connect the
green clip to earth, black to neutral and red to live in that order and then plug the
TL88 lead into the IEC inlet socket of the E-ZeTest EZ2500.
3.3.2 Start Up
Every time the E-ZeTest EZ2500 is plugged in it will, display a brief series of
messages, before it calculates and displays the Phase Neutral Loop Impedance,
Phase Earth Impedance and related fault currents.
Note:
If the E-ZeTest EZ2500 display does not illuminate, this could mean that
the supply voltage is less than 30V, or could mean a simultaneous fault on both
earth and neutral (see Precautions section 3.1).
Verify the E-ZeTest EZ2500 in a known correctly-wired socket. If the E-ZeTest
EZ2500 is shown to be functioning correctly, investigate the socket where a fault
response occurred.
3.3.3 Phase Neutral & Earth Loop Impedance Test
If the wiring is correct and the supply voltage of the circuit under test is between
198V and 264V the E-ZeTest EZ 2500 will perform a Phase Neutral and Earth
Loop Impedance check automatically. No interaction is required by the user;
simply note down the Phase Neutral and Earth Loop Impedance value displayed
at the end of the message sequence.
3.3.4 Wiring and Voltage Check
If the E-ZeTest EZ2500 detects a fault condition in the wiring under test, or the
supply voltage is less than 198V (<198V) or greater than 264V (>264V), or the Earth
Loop Impedance is greater than 3000
Ω
(>3000
Ω)
or Phase Neutral Impedance is
greater than 3000
Ω
, the LCD will display an appropriate message or set of
messages, according to table 3.4. The Phase Neutral and Earth Loop Impedance
measurements will not be displayed depending on error and noise conditions
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encountered whilst measuring.
In such circumstances, always have suspect wiring investigated and unplug as
many unnecessary appliances from the mains as possible.
Note:
It is always better to unplug an appliance completely rather than merely switch it off.
Note:
The E-ZeTest EZ2500 is designed to operate and detect faults if phase is
available on any one of the three input pins and a neutral or earth return is available
on one or both of the remaining two input pins. This ensures that the unit will alert the
user to the need for investigation under a wide variety of wiring fault conditions.
The fault messages that are displayed relate to the most common wiring faults.
However, these common wiring faults share symptoms with other unusual faults
that may exist.
In such circumstances, the wiring fault could be different to that reported on the display.
For example, the symptoms detected and displayed as a "phase neutral reversed"
fault would also be present for a fault where the neutral was open between the
distribution board and the socket under test and the neutral was shorted to the
phase within the socket under test.
Therefore, always investigate wiring faults with care, testing for live voltages on all
pins. Ensure that all wiring faults are rectified without delay.
Note:
An indicated low voltage value, or a “ Voltage Low” message, may be the
result of a low supply voltage, or be the result of a high impedance value on the
incoming phase conductor.
Note:
As with all other testers, the E-ZeTest EZ2500 does not detect earth-neutral
reversal.
3.3.5 Repeat measurements
If the E-ZeTest EZ2500 is left plugged into a socket, the display will not be updated
but will continue to show the last measured value of Phase Neutral and Earth Loop
Impedance.To take a fresh measurement, disconnect the E-ZeTest EZ2500 from
the supply then re-connect, to re-start the measurement process.
