YOKOGAWA CL320 User Manual

User’s
Manual

CL320
Leakage Clamp-on Tester

IM CL320

Contents

 Precautions for Safety Use of the Instrument

1. Instrument Layout

2. Measurement

2.1 Preparation for Measurement

2.2 AC Current Measurement

2.3 How to Use Frequency Selector Button

2.4 Peak Current Measurement

3. Other Functions

3.1 Auto-Power-Off Function

3.2 Data Hold Function

3.3 Optional Accessories

4. Battery Replacement

5. Specifications

6. Calibration and After-sales Service

 Precautions for Safe Use of the Instrument

When handling the instrument, ALWAYS observe all of the cautionary
notes on safety given below. Yokogawa M&C Corporation is not at all
liable for damage resulting from misuse of this product by the user
that is contrary to these cautionary notes.
Various symbols are used on the instrument and in this manual to
ensure the product is used safety and to protect operators and prop­erty from possible hazards or damage. The following safety symbols
are used where appropriate. Read the explanations carefully and
familiarize yourself with the symbols before reading the text.

The instrument and this manual use the following safety symbols:

Danger! Handle with Care.

This symbol indicates that the operator must refer to an ex­planation in the User’s Manual in order to avoid the risk of
personal injury or death and/or damage to the instrument.

Double Insulation

This symbol indicates double insulation.

AC Voltage/Current

This symbol indicates AC voltage or current.

Ground

Indicates that there is a possibility of serious personal injury or loss of
life if the operating procedure is not followed correctly and describes
the precautions for avoiding such injury or loss of life.

Indicates that there is a possibility of serious personal injury of dam­age to the instrument if the operating procedure is not followed cor­rectly and describes the precautions for avoiding such injury or dam­age.

NOTE

Draws attention to information essential for understanding the opera­tion and features.

● Never make measurement on a circuit above 300V AC.

● Do not use the instrument in an atmosphere where any flammable

● Do not attempt to make measurement in the presence of flamma-

● Avoid using the instrument if it has been exposed to rain or mois-

● Do not exceed the maximum allowabIe input of any measurement

This symbol indicates ground (earth)

WARNING

CAUTION

WARNING

or explosive gas is present.

ble gasses, fumes, vapor or dust. Otherwise, the use of the instru­ment may cause sparking, which can lead to an explosion.

ture or if your hands are wet.

range.

1st Edition: Apr. 2003 (MC)

IM CL320

● Never open the battery compartment cover when making meas­urement.

● Do not use the instrument if there is any damage to the casing or
when the casing is removed.

● Do not install substitute parts or make any modification to the in­strument. Return the instrument to Yokogawa M&C or your dis­tributor for repair or re-calibration.

● Always switch off the instrument before opening the battery com­partment cover for battery replacement.

WARNING

To avoid damage to the instrument or electric shock!
The restrictions on the maximum voltage level for which the CL320
testers can be used, depend on the over-voltage categories specified
by the safety standards. These category specifications are formulated
to protect operators against transient impulse voltage in power lines.

Function

Over-voltage category I (CAT.I):

Signal level, special equipment or parts of equipment, telecommunication,

electronic etc., with smaller transient over-voltages than CAT.II.

Over-voltage category II (CAT.II)

Local level, appliance, portable equipment etc., with smaller transient

over-voltages than CAT.III.

Over-voltage category III (CAT.III):

Distribution level, fixed installation, with smaller transient over-voltages than

CAT.IV.

A

Maximum Allowable Input

OVERVOLTAGE CATEGORY III

Measuring circuit voltage : 300Vrms AC

200Arms AC

CAUTION

● Be sure to set the Range switch to the "OFF" position after use.

When the instrument will not be in use for a long period of time,
Place it in storage after removing the battery.

● Use a damp cloth and detergent for cleaning the instrument. Do not
use abrasives or solvents.

NOTE

● Radiation immunity affects the accuracy of CL320 testers under the
conditions specified in EN 61000-4-3:1997.

● If equipment generating strong electromagnetic interference is
located nearly, the testers may malfunction.

1. Instrument Layout

Open/Close Lever

Transformer

LCD

Frequency
response of
50/60Hz

Frequency
response of WIDE

Low battery indicator

Data Hold Switch

Range Switch

Frequency Selector Switch

Data hold mode
indicator

Unit of measurement
quantity

Hand Strap

Display

2. Measurement

2.1 Preparation for Measurement

WARNING

Do not make measurement on a circuit above 300V AC. This may
cause shock hazard or damage to the instrument or equipment under
test.

CAUTION

● The jaw section is a delicate, precision sensor. Do not subject the

jaw to unreasonably strong shock, vibration, or force when using it.

● If dust gets into the tops of the jaws, remove it immediately. Do not

close the jaws when dust is trapped in its joints as the sensor may
break.

● Please check that the Range switch is set to the desired position

before measurement.

NOTE

● During current measurement, keep the transformer jaws fully

closed. Otherwise, accurate measurement cannot be made. The
maximum measurable conductor size is approx. 24mm in diameter.

● When measuring large current, the transformer jaws may buzz.

This has no effect on the instrument’s performance or safety.

2.2 AC Current Measurement

(1) Set the Range switch to the desired position. Current to measure

should be within the selected measuring range.

(2) Normal measurement :

Press the jaw open/close lever to open the transformer jaws and
close them over one conductor only. Measured current value is
shown on the display. Earth leakage current or small current that
flows through a grounded wire can also be measured by this
method.

Correct Wrong

Load

(3) Measuring out of balance leakage current :

Clamp onto all conductors except a grounded wire. Measured
current value is shown on the display.

Load

3-phase 3-wire

Note : In case of 3-phase 3-wire,
clamp four wires for measurement.

Note : In case of 1-phase 3-wire,
clamp three wires for measurement.

1-phase 2-wire

2.3 How to Use Frequency Selector Button

When high frequencies from such equipment as inverters are present
in the circuit under test, the instrument measures AC current of not
only 50Hz or 60Hz of fundamental frequency but also of these high
frequencies and harmonics.
To eliminate the effect of such high frequency noise and measure AC
current of 50Hz or 60Hz fundamental frequency, a "high-cut" filter
circuit in incorporated into the instrument which works when
"50/60Hz" frequency response is selected with the Frequency Selec­tor button. Cut-off frequency of "high-cut" filter is about 100Hz with
attenuation characteristic of approx. -24dB/octave.

NOTE

Characteristic of -24dB/octiave means that signal magnitude declines
to about one sixteenth of that at the initial frequency when frequency
doubles.
The Frequency Selector button has the following two positions.

● WIDE (40Hz or more) :
Permits measurement of currents of fundamental frequencies as
well as currents of high frequencies generated by such equipment
as inverters.

● 50/60Hz (40 to approx. 100Hz) :
Filters out high frequency currents and measures current of fun­damental frequency only.

When the
left side of the display. When the
frequency response is switched to WIDE with "WIDE" mark shown on
the display.

Attenuation

(dB)

Recently there has been increased use of power through inverters,
switching regulators, etc. When the high frequency noise from such
appliances leaks or flows into the ground through capacitors not
filtering completely, the earth leakage breaker may trip even though
there is no "actual" leakage. In such a case, the instrument do not
give leakage current reading if "50/60Hz" frequency response is se­lected.
Take care readings with the 50/60Hz and WIDE frequency responses
respectively to make effective use of the Frequency Selector button.

button is pressed, "50/60Hz" mark is shown on the

Frequency characteristics

button is pressed again,

All ranges WIDE

position

All ranges at 50/60Hz Position
(-24dB/oct)

f (Hz)Frequency

Load

3. Other Functions

3.1 Auto-Power-Off Function

This is a function to prevent the instrument from being left powered on
and conserve battery power. The instrument automatically turns off
about 10 minutes after the last switch or button operation. To return to
the normal mode, turn the Range switch to OFF, then to the desired
position.

3.2 Data Hold Function

Load

This is a function to freeze the reading on the display. When the

button is pressed once, the current reading is held even though
current under test varies. "
corner of the display.

To exit the data hold mode, press the

NOTE

When the auto-power-off function works while the instrument is in the
data hold mode, data hold is cancelled.

" mark is shown on the upper right

button again.

3.3 Optional Accessories

Clamp Adapter Model 99025 (For AC current measurement only)

Clamp Adapter Model 99025 is designed to increase the measuring
capability of a clamp meter. With the use of the Clamp Adapter, you
can not only extend current range over 2000A, but also clamp on a
large bus-bar or conductor.

(1) Set the Range switch to the desired position.
(2) As shown in the figure right, clamp Model CL320 onto the pickup

coil of Model 99025.
(3) Clamp Model 99025 onto the bus-bar or conductor under test.
(4) Take the reading on Model CL320 and multiply it by 10.

NOTE

The clamp adapter is not applicable to leakage current measurement.
For detailed specification, refer to the Clamp Adapter User’s Manual.

4. Battery Replacement

WARNING

To avoid electric shock hazard, never try to replace batteries during
measurement.

CAUTION

● Do not mix new and old batteries.

● Make sure to install battery in correct polarity as indicated in bat-

tery compartment.

Percentage

If the battery voltage becomes too low for the instrument to operate
normally, "
Note that when the battery is completely exhausted, the display
blanks without "

(1) Set the Range switch to the "OFF" position.
(2) Press in the hole on the battery compartment cover with the tip of

a pointed object, then slide open the cover.
(3) Replace the battery observing correct polarity. Use two new

LR-44 or SR-44 batteries.
(4) Slide the battery compartment cover back in place.

" is shown on the display. Then, replace the battery.

" shown.

5. Specifications

 Instrument Specifications

Measuring Ranges and Accuracy (at 23 ±5°C, relative humidity up to 75%)

AC Current

Ranges

40mA 0 to 19.99mA

200mA 0 to 199.9mA

200A

General Specifications

● Operating System : Dual integration

● Measurement Function : AC current

● Display : Liquid crystal display with maximum counts of 1999

● Overrange Indication : "1" flashes on the highest digit

● Response Time : Approx. 2 seconds.

● Sample Rate : Approx. 2 times per seconds.

● Temperature and Humidity for Guaranteed Accuracy : 23°C ±5°C,

relative humidity up to 75% without condensation

● Operating Temperature and Humidity : 0 to 40°C, relative humidity
up to 85% without condensation

● Storage Temperature and Humidity : -10 to 50°C, relative humidity
up to 75% without condensation

● Effect of conductor position :

The difference between maximum and minimum values to a 10

mm-dia conductor, at every part inside the jaws;
Within 5dgt for 0 to 50A
Within 2% for 50 to 200A

● Effect of external magnetic field : 10 mA or less in proximity to a

14.5 mm-dia conductor carrying 100 A

● Effect of residual current : 10 mA or less in proximity to a 10
mm-dia conductor carrying 50 A

● Power Source : Two LR-44 or SR-44 battery

● Battery Life : Approx. 15 hours (continuous)

● Current Consumption : Approx. 5mA

● Auto-power-off function : Turns power off approx. 10 minutes after

the last switch operation

● Withstanding Voltage : 3700V AC, 1 minute between electrical
circuit and housing case or metal part of the jaws

● Insulation Resistance : 10MΩ or greater at 1000V between elec-
trical circuit and housing case or metal part of the jaws

● Conductor Size : Approx. 24mm diameter max.

● Dimensions : Approx. 60(W) x 149(H) x 26(D) mm

● Weight : Approx. 120g

● Safety Standard: EN 61010-1

● EMC Standard : EN 61326

EN 55022

● Accessories : LR44 batteries···························2

● Optional Accessories : Clamp adapter Model 99025

Measuring

range

0 to 100.0A

100.1 to 199.9A

Carrying case Model 93033·······1
User’s Manual ···························1

WIDE position 50/60 position

±2.0% rdg ±4dgt
(50/60Hz)
±5.0% rdg ±6dgt
(40 to 400Hz)

±5.0% rdg ±4dgt
(50/60Hz)

EN 61010-2-032
(300V AC CAT III, Pollution degree2, indoor use)

Accuracy

Frequency Selector Switch

±3.0% rdg ±5dgt
(50/60Hz)

±5.0% rdg ±5dgt
(50/60Hz)

6. Calibration and After-sales Service

Should any failure occur while you are using the tester, follow the
instructions given below. If the tester still fails to operate correctly and
needs repair, contact the vendor from whom you purchased the in­strument or the nearest Yokogawa M&C sales office.

● Turn off the POWER switch once, then turn it back on again.

● If the tester does not turn on, replace the battery with a new one.

Calibration
It is recommended that the instrument be calibrated once every year.

YOKOGAWA M&C CORPORATION
International Sales Dept.

2-9-32 Nakacho, Musashino-shi, Tokyo, 180-8750 Japan
Phone: [phone] Facsimile: 81-422-55-8654

YOKOGAWA CORPORATION OF AMERICA (U.S.A.)

Phone: [phone] Facsimile: 1-770-251-2088

YOKOGAWA EUROPE B. V. (THE NETHERLANDS)

Phone: [phone] Facsimile: 31-334-64-16 10

YOKOGAWA AMERICA DO SUL S. A. (BRAZIL)

Phone: [phone] Facsimile: 55-11-5681-1274

YOKOGAWA ENGINEERING INSTRUMENTS KOREA CORPORATION (KOREA)

Phone: [phone] to -0664 Facsimile: 82-2-551-0665

YOKOGAWA AUSTRALIA PTY. LTD. (AUSTRALIA)

Phone: [phone] Facsimile: 61-2-9888-1844

YOKOGAWA BLUE STAR LTD. (INDIA)

Phone: [phone] Facsimile: 91-80-227-4270

LTD. YOKOGAWA ELECTRIC (RUSSIAN FEDERATION)

Phone: [phone] Facsimile: 7-095-737-7869

KIM3E-2003.2