KW1M-H Eco-POWER METER
7
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When measuring a load with exceed input voltage
Voltage transformer (VT) is needed when you measure a load with over rated input voltage (440V).
Use VT, those secondary rating is 110V.
Grounding the secondary side of VT and CT is not necessary with low-voltage circuit.
Single-phase two-wire system
Single-phase, three-wire system
Three-phase, three-wire system
Three-phase, four-wire system
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Using the clock correction function by frequency of the measured voltage
It corrects the clock by using the measured voltage frequency input to P1-P0 as a reference
frequency.
When P1-P0 terminals are not connected or it set OFF for clock correction function, it doesn’t correct
the clock.
3.3 How to attach the Current Transformer (CT)
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One current transformer (CT) is needed to measure 1P2W system. Two CTs are needed to measure a
1P3W/3P3W system. Three CTs are needed to measure a 3P4W system. Using all CT should be the
same.
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Check beforehand that the thickness of the electric wire is smaller than the through-hole of the CT.
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When connecting CT, connect the secondary side to the terminal of the main unit first, and after that
wire the primary side to a load electric wire.
Incorrect order might cause an electric shock or break CT.
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The CT has polarity. Wire correctly according to the K and L marks.
Wrong direction can’t measure correctly.
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When closing clamp-on type CT, check that there is no foreign materials on the divided face. And
make sure it is closed securely once the wire is in place;
if not the measurement value will be not
accurate.
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When CT’s cable is extended, it is possible to extend up to about 10m with the cable of AWG#22 or
more cross section under the environment without noise at all. Please use the thick cable as much as
possible. *Please check beforehand with the actual system in case of extending the cable.
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If there is some distortion by harmonic or waveform, it may not measure correctly. Please check with
the actual system before adopting it.
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Separate the wiring (strong electric part) of the measured voltage input terminal (operating power
supply terminal) from the CT cable. It may not satisfy the accuracy due to noise.
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Only same color housing of cable and connector of CT can be connected.
That of different color (blue and white) can't be connected.
