KYORITSU 6011A - Manual (Page 23)

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Fig 10
BLACK NEUTRAL
RED PHASE
GREEN EARTH
7. PROSPECTIVE SHORT CIRCUIT CURRENT（PSC）TESTS
WARNING
NEVER CONNECT THIS INSTRUMENT ACROSS 2 PHASES.
N E V E R AT T E M P T TO M E A S U R E T H E P H A S E TO P H A S E
PROSPECTIVE SHORT CIRCUIT CURRENT.
7.1 What is Prospective Short Circuit Current?
The Prospective Short Circuit or Fault Current at any point within an electrical
installation is the current that would flow in the circuit if no circuit protection
operated and a complete (very low impedance) short circuit occurred. The value
of this fault current is determined by the supply voltage and the impedance of the
path taken by the fault current. Measurement of Prospective Short Circuit Current
(PSC) can be used to check that protective devices within the system will operate
within safety limits and in accordance with the safe design of the installation.
7.2 Testing Prospective Short Circuit Current
PSC is normally measured at the distribution board between the phase and
neutral, or at a socket outlet between phase and earth.
If testing at a distribution board proceed as follows:-
In order to test the PSC, the OMA DIEC(Model7133) of option is necessary.