YOKOGAWA CTW10 User manual
Models CTW10, CTW20, CTW100,
and CTW130
Clamp-on Current
Transformers
4. INSTALLATION
WARNING
Since there is a risk of electric shock during
installation, be sure to observe the following.
●Before connecting the transformer to any other
equipment, make sure the circuit is not receiving
any power in order to prevent electric shock.
●Fasten the connecting terminals securely so they
will not loosen readily.
●Do not touch the terminals or any other part of the
transformer when the circuit is live.
●Do not use the transformer under a circuit current
greater than the level specied for that model.
●Do not use the transformer under a circuit voltage
greater than 500 V AC.
CAUTION
The CTW contains a device for suppressing hazardous
voltages that ay arise when the secondary line is open-
circuited.
Install the transformer referring to the following gures.
Cable
Power-source side
K
Load side
L
Secondary-stage cable
k side = white; l side = black
Buckle
Example of Installation
①
Pull the buckle
in the direction
of the arrow.
①
How to Remove
Hook
①Hook the buckle.
②
Push the
buckle in the
direction of
the arrow
until it clicks.
②
①
How to Install
1.
CAUTIONARY NOTES FOR SAFE USE OF THE
PRODUCTS
The following symbol is used on the product and in this manual to
ensure safe usage.
WARNING
Calls attention to actions or conditions that could
cause serious or fatal injury to the user, and indicates
precautions that should be taken to prevent such
occurrences.
CAUTION
Calls attention to actions or conditions that could
cause injury to the user or damage to the instrument
or property and indicates precautions that should be
taken to prevent such occurrences.
2. CROSS-CHECK THE MODEL
Make sure the model and sux codes shown on the data plate
attached to the transformer are the same as specied in your
purchase order.
Models Names
CTW10 Clamp-on Current Transformer (for 100 A / 1 A)
Applicable cable diameter: less than Φ24 mm
CTW20 Clamp-on Current Transformer (for 200 A / 1 A)
Applicable cable diameter: less than Φ24 mm
CTW100 Clamp-on Current Transformer (for 500 A / 5 A)
Applicable cable diameter: less than Φ36 mm
CTW130 Clamp-on Current Transformer (for 800 A / 5 A)
Applicable cable diameter: less than Φ36 mm
3. HANDLING PRECAUTIONS AND
INSTALLATION LOCATION
CAUTION
●Note that these current transformers are designed
for use with general-purpose instruments and have
not yet gained any ocial certication. They cannot
therefore be used for the purpose of ascertaining
wattage or other electric parameters.
●Use each current transformers under a load no
greater than its rated level. When calculating
the load, you must calculate the sum of the load
given by the instruments to be connected to the
transformer and the load given by the lead-wire of
the secondary-stage cable.
●The inner-walls of the clamp are treated with rust
preventive. But if rusted, remove the rust with
CRC-5-56 (goods on the market) and spray rust
preventive on the inner-walls again for recovery.
Avoid installing the current transformers in locations subject to:
ambient temperatures outside the specied range of -20 °C to
50 °C, where condensation is likely; ambient humidity exceeding
80 % RH, where condensation is likely; relatively large amounts
of ammable or explosive gas, saline substance, lampblack or
dust; splashes of water, oil or solvent; radioactive rays or intense
electric or magnetic elds; frequent mechanical vibration or
shock; or direct sunlight.
IM 77C01W02-01E
©Copyright Nov. 2003
3rd Edition: Nov. 2019
User’s
Manual
1
Thank you for purchasing the Clamp-on Current Transformers.
Please read through this manual before use for correct handling.
2-9-32, Naka-cho Musashino-shi, Tokyo 180-8750 Japan
http://www.yokogawa.com/ns/powercert/
You can download the latest manuals from the following website:
● Attach the transformer to the cable according to the orientation
of the K and L symbols, as shown in the gure.
● Securely fasten the clamp using the buckle.
● Use a crimp-on terminal for 0.75 mm2 cables to connect the
secondary-stage cable.
● The wires of the secondary-stage cable are color-coded as
follows. k side=white; l side=black
Secure the current transformer and cable with a commercially
available cable tie as shown in the photo below.
CAUTION
When extending secondary-stage cable of the current
transformer, use a covered ring-sleeve or the like and
a cable of 1.25 to 2 mm². The standard cable length is
as follows.
When secondary-stage current is 5 A:
Up to 2.6 m for 1.25 mm², and up to 4.6 m for 2 mm²
When secondary-stage current is 1 A:
Up to 8.3 m for 1.25 mm², and up to 15 m for 2 mm²
5. DISPOSAL
These current transformers, when no longer serviceable, must be
disposed of as industrial refuse.
6. SPECIFICATIONS
6.1 General
The CTW series are clamp-on current transformers that can be
installed much easier than conventional current transformers,
whereby saving labor. These transformers are particularly useful
when expanding existing system since you can attach them to a
cable without having to cut it.
6.2 Characteristic Specications
Rated primary current (In) / Rated secondary current:
CTW10= 100A / 1A
CTW20= 200A / 1A
CTW100= 500A / 5A
CTW130= 800A / 5A
Rated frequency: 50 / 60 Hz
Rated burden:
CTW10, CTW20 = 0.5VA
CTW100, CTW130 = 2.5VA
Accuracy / Linearity: ±1.0% against rated primary current In
Phase dierence: Within ±2° against rated primary current In
Operating circuit voltage: Within 500 V AC
Insulation resistance: 100 MΩ or more at 500 V DC (across core
and output)
Withstand voltage: 2000 V AC for one minute (across core and
output)
Operating temperature range: -20 to 50°C (no condensation)
Operating conditions: Indoor location
Weight:
CTW10= Approx. 220 g
CTW20= Approx. 220 g
CTW100= Approx. 350 g
CTW130= Approx. 380 g
7. EXTERNAL DIMENSIONS
7.1 CTW10 and CTW20
43
25
41
42
0.75mm2×300l-2C
K
L
Φ70
Φ24
7.2 CTW100 and CTW130
53
25
51
42
0.75mm2×300l-2C
Φ90
Φ36
K
L
2IM 77C01W02-01E 1st Edition Nov.29. 2019-00
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3
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