Panasonic KW8M, Руководство пользователя

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KW8M Eco-POWER METER
8
◆
How to attach the Current Transformer (CT)
・
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.
・
Check beforehand that the thickness of the electric wire is smaller than the through-hole of the CT.
・
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.
・
The CT has polarity. Wire correctly according to the K and L marks.
Wrong direction can’t measure correctly.
・
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.
・
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.
･
If there is some distortion by harmonic or waveform, it may not measure correctly. Please check with
the actual system before adopting it.
・
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.
◇
To connect CT with secondary current 5A
How to connect the unit to measure by combination with existing commercial CT
(1) Select 5A at CT type setting mode (CT-T).
(2) Set the primary current of measured commercial CT (secondary current 5A) at primary side
current of CT setting mode (CT-1).
< ex > If the measured CT is 400A/5A, set to”400”.
(3) Clamp the dedicated CT for 5A (AKW4801), which is connected to the main unit first, to
secondary side of the commercial CT. CT direction (K
→
L) should be set for the commercial CT
direction.
(Connection example)
With Ammeter etc.
Secondary current
Breaker
Dedicated CT for 5A
Ammeter etc.
Power supply
CT with 2nd current 5A
L K
K
L
Eco-POWER
METER
Load