NNoo TTrriipp MMooddee
For Zs testing where the circuit being tested is protected by an RCD there is the No Trip Loop
Test mode. In this mode testing can be made at sockets on the final circuit without fear of
tripping the RCD under normal circumstances.
This is achieved by testing at a current that is too low to trip an RCD on an otherwise healthy
circuit. The No Trip test is a 3-wire test that also checks the Live, Neutral/Earth conductors are
correctly connected before running the loop test.
Note- if there is abnormal standing leakage current on the circuit such as a faulty Microwave
Cooker for example then this abnormal leakage is added to low current used for the above test
and the RCD may trip.
However this can be seen as an advantage since it is pointing to a faulty appliance that should
be rectified or replaced.
Whilst No-Trip testing at points on the final circuit will normally function with a high level of
accuracy, it should be noted that the low current measurement technique used is more likely to
be adversely affected by external factors such as noise on the mains supply.
Circumstances such as testing at seldom used socket outlets with tarnished contacts or testing a
circuit with a lot of background noise from electronic apparatus can result in the occasional
erroneous reading.
For this reason it is recommended that multiple measurements are made when using the No-trip
mode and any isolated odd results are ignored. When taking multiple readings the tester should
be disconnected from the supply between consecutive tests.
For safety reasons the No-Trip mode is recommended for all measurements made on TT
systems.
Where practical all other equipment powered by the same circuit should be switched off before
testing. This will reduce the chances of the RCD tripping as a result of combined leakages.
PPFFCC//PPSSCC
In both Loop test mode the Ethos 8400 will also display the supply voltage and at the touch of
the PFC button the PFC/PSC depending on being connected L-E or L-N will be displayed.
TTeesstt lleeaadd ccoonnffiigguurraattiioonn
The Ethos 8400 Loop test function can be used with 2 types of connecting lead. It is important
to understand and use the correct lead configuration for each test mode or you may not obtain
the correct results.
Lead options
Ethos 2126 mains lead with 3 x 4mm plug to 13A plug
Ethos 2125 3-pole distribution board test lead set that can be fitted with either prod tips or
crocodile clips as required.
19
EETTHHOOSS 88440000
INSTRUCTION MANUAL
Mains supply wiring and voltage test
When first connected to a mains supply the Ethos 8400 will automatically conduct a safety test
to ensure that the Live, Neutral and Earth conductors are all connected correctly and that the
supply voltage is in the acceptable range (207-230V)
If all is well the VOLTAGE/POLARITY warning LED will light Green and the supply voltage will
be displayed in the primary display area.
In the event of a problem with either the mains voltage supply or reversed connections the
VOLTAGE/POLARITY warning LED will light Red, a warning tone will be sounded and testing
will be inhibited.
This condition will be indicated for you safety.
LLoooopp TTeesstt PPrroocceedduurreess
HHaannddss FFrreeee LLoooopp TTeessttiinngg
The hands free feature can be used in either No Trip or high current test modes.
To enable the hands free feature simply press Test Lock button once,The ‘T-LOCK’ annunciator
will appear flashing on the display and will continue to do so until cancelled by a further press
of the Test Lock button or by changing the function selector switch.
When the ‘T-LOCK’ annunciator is flashing all you need to do is connect the test lead to a mains
supply and the test will be carried out.
HHiigghh CCuurrrreenntt mmooddee
For Ze testing at the distribution board or at any point upstream of RCD protection there is a
traditional fast high current test mode. The high current mode is a 2-wire test that enables the
user to test the true impedance of both the Line-Neutral Loop and the Line-Earth loop and
therefore to establish both the PSC (prospective short circuit current) and the PFC (prospective
fault current) for the installation.
Unlike most testers that only measure the resistance of the Loop, the high current mode of the
Ethos 8400 will measure the impedance of the Loop which includes an element of reactance.
This can be significant where the distribution board is close to the mains supply transformer and
is therefore much more accurate than older Loop testing techniques.
You should be aware that because of this there may well be variations in reading compared to
ordinary loop testers or to the non-trip function of this tester, particularly when the
measurement is made near to the mains supply transformer.
18
EETTHHOOSS 88440000
INSTRUCTION MANUAL
To Next Page
Loading...