Connection Diagrams - Circutor Getest Instruction Manual

7.-

CONNECTION DIAGRAMS

Hardware earthing and auxiliary earthing connection
Connect one of the GETEST's injection terminals (IP) to the hardware earthing or the transformer
substation's or substation's protection earthing. Do not confuse the hardware earthing with that of
the service, although in some earthing systems they will be interconnected. Connect the other
GETEST injection terminal (IP) to the auxiliary earthing that we have previously created. As an
example, if you wish to inject 5 A you must have a sum of earthing connections that does not
exceed 110 Ω and for 50 A it must not exceed 10 Ω
You must find or build a good auxiliary earthing, as it will determine whether the unit
can inject the test current. Bearing in mind that the ohmic value of the hardware
earthing can not be reduced; try to reduce the auxiliary earthing resistance instead. If
you use spikes to make an auxiliary earthing, you can reduce the ohmic value if you
add more spikes in parallel, wet the ground itself, nail the spikes deeper into the
ground, etc.
There are several options for making an auxiliary earthing:
• Use a neutral earthing from the installation as long as it is not connected to the hardware
earthing.
• Nail several spikes into the ground with some distance between them.
• Use the earthing from other elements outside the transformer substation or substation
Hardware earthing detail
Page 18 of 24
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