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7 Setting and procedure for operation
QE81WH4W
7.5.3.1 Current circuit connection
For the current circuit connection, there are two ways as follows:
1) You can connect current sensor to the circuit, or
2) You can attach the 5 A current sensor to the secondary of the existing current transformer.
(1) To attach current sensor (for low voltage circuit) to the circuit
Select an appropriate current sensor according to the current capacity of the circuit to be measured.
Item
Specifications
Model name
EMU-CT50
EMU-CT100 EMU-CT250 EMU-CT400 EMU-CT600
Primary current
50 A
100 A
250 A
400 A
600 A
Supplementary
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Make sure that before connecting the cable, the orientation of the current sensor is correct for
attachment. K to L is the correct direction. K: power source side, L: load side.
The length of the cable to be used for wiring is 50 m max for the following device: EMU-CT50,
EMU-CT100, EMU-CT250, EMU-CT400, EMU-CT600.
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How to attach EMU-CT50/CT100/CT250
Follow the procedure below to attach to the cable of the target
circuit.
Primary
conductor
(Cable)
Movable core
Fixing hook
Movable core
Fixing hook
Movable core
Stopper
Movable core split
surface
Protective cover
1) Open the movable core, as shown in the figure on the right.
Lift slowly the hooks located on both sides of the movable core, and
detach them from the stopper.
Do not force to open it. You may
break the hook.
2) Do not let the cable touch on the core-spilt surface. Thus, carefully
pass the cable from underneath. Before passing the cable, check the
direction symbols of K and L, in order to attach the sensor in the
correct orientation. (Direction from power source
side (K) to load side (L) is indicated with the
arrow.)
3) Make sure no dust or foreign object is attached
on the split-core surface, and after that, close the
movable core. Lift the movable core until the
stoppers are firmly locked. (When the hooks on both side of movable
core are locked to the stoppers, you will hear click sound twice.)
H ole for fixing
(3×2)
H ole for fixing
(3×2)
Binding band
Binding band
Primary
conductor
(Cable)
Current
direction
4) Put a binding cable through a hole for fixing the current sensor, and
then tie it with the cable. Do not tie it too tightly. (Holes for fixing the
current sensor are located on both side of the current sensor. )
5) Cut off the extra portion of binding cable, using a nipper, etc, to
avoid interference of the cable.
6) Lift a protective cover of the secondary terminal, by holding the center
portion of the protective cover, and remove it. And then, connect the
given sensor cable.
Check the terminal symbols printed on the
secondary terminal surface, so that connection is performed
correctly.
Supplementary
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When opening the movable core on current sensor,
do not widen the hook for fixing the
movable core too widely.
It may break the hook.
Refer to the table below for appropriate size of electric wires.
EMU-CT50
EMU-CT100
EMU-CT250
EMU-CT400
EMU-CT600
IV cable
60 mm
2
or less
60 mm
2
or less
150 mm
2
or less
500 mm
2
or less
500 mm
2
or less
Usable wires
size (reference)
CV cable
38 mm
2
or less
38 mm
2
or less
150 mm
2
or less
500 mm
2
or less
500 mm
2
or less
Size of electric wires conforms to what is described in the catalog of general PVC insulated
wires. Thickness of external PVC insulation is different for different wire. Check with the external
dimension diagram of this product and make sure the wire can go through the given space.
