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This manual will guide you through the functions of the TPI 85
which will give you many years of reliable service.
Your TPI 85 Multi-Function Earth Loop Tester comes complete
with:
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One Test lead incorporating a UK style 3 pin plug (fitted with
a 13 Amp fuse) at one end and a IEC type connector fitted
at the other end, which interfaces with the instrument for
testing via Socket Outlets
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A second test lead which is equipped with 3 separate probes
to enable testing via connections other than where a Socket
Outlet is present
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Instruction Manual
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Carry Case
2. Why Measure Earth Loop Impedance?
Whereas a digital multi-meter can be used to prove correct
wiring, voltage and polarity, the checking of Earth-Loop
Impedance can only be achieved using an instrument
specifically designed for this purpose.
The term ‘Impedance’ is defined as “the delay, or the preventing
of progress of something”. In the case of electricity, it is better
defined as “the opposition in a circuit to the flow of alternating
current, consisting of resistance and reactance”.
The TPI Multi-Function Tester is designed to indicate ‘Earth
Loop Impedance’, which can best be explained as a function
that can measure the resistance and reactance to the flow of an
alternating current in an electrical circuit.
Whereas measuring ‘Resistance to Earth’, using a digital multi-
meter will show that there is a good connection with low
resistance, between the two points being measured; it does not
prove how efficient the path to earth will be under fault
conditions.
5. Calibration & Servicing.
It is recommended that the unit is checked and calibrated as
annually. If required, TPI provide a service for the checking and
recalibration of instruments. Please consult Test Products
International for further details.
Appendix A:
Fault Conditions Indication Chart
The chart below details the correct and fault conditions as
indicated by the various combinations of LED’s as shown by
the ‘Correct Wiring Indicator’ display
Display
Tone
Condition Indicated
●
●●
Continuous
(3 seconds)
Correct
Intermittent
L & E reversed, or L, N, E Incorrectly
connected
Intermittent
L & N reversed, or L, N, E Incorrectly
connected
Intermittent
Neutral Fault, or L & E Incorrectly
connected
Intermittent
Earth Fault, or L & N reversed
Intermittent
Live Fault, or N & E Incorrectly
Connected
Ο
Ο
Ο
None
No mains present
(confirm against known power source)
Key:
●
Continuous display of LED to indicate correct condition
= Flashing display of LED to indicate fault condition
Ο = Blank display to indicate no power to LED
= green flashing LED. = Orange flashing LED.
=Red flashing LED