-
After making the changes, press the
OK
key.
Please refer to section 4.7 if an external clamp-on current
transformer is used.
7.
Pressing
ESC
function key, will return the user to the three-phase
measurement screen.
8.
Phase A voltage input is taken as the reference for phase angle
measurement. The operator may change the reference to either
VAN, VBN, VCN, IA, IB
or
IC
, by pressing the
Select Phase Ref
function key.
4.7
CLAMP-ON CURRENT AND POTENTIAL TRANSFORMER OPERATION
For application requiring direct measurement of primary current, five different
optional clamp-on current transformers ratios are pre-set with this instrument.
These ratios are
1000:1
,
1000:5
,
3000:1
,
3000:5
and
200:1
. If the clamp-on
being used does not match any of the pre-set options, simply move the cursor to
the
Customize
CT or PT.
There are two manners in which the clamp-ons can be utilized:
1.
Measuring Primary current, watts and vars in a single- or three-phase
installation.
2.
Verifying the ratios of CTs, used in relaying and metering installations.
The following sections detail the operation for each of these applications.
4.7.1
MEASURING
PRIMARY
CURRENT
1.
For this application, connect the clamp-on CT(s) directly to the
current channel terminals on the front panel. Up to three clamp-ons
can used for three-phase applications. Note that the CTs are only
rated for 600 Volts class circuits.
2.
To select the clamp-on ratio desired, proceed as follows:
20
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