Hioki 3120 User manual

Overview
This noncontact type of voltage detector unit enables the hot-line
state of AC voltage to be checked through the wire or cable cover-
ing.
Initial Inspection
When you receive the instrument, inspect it carefully to ensure that no
damage occurred during shipping. If damage is evident, or if it fails to
operate according to the specifications, contact your dealer or Hioki rep-
resentative.
Maintenance and Service
• To clean the instrument, wipe it gently with a soft cloth moistened
with water or mild detergent. Never use solvents such as ben-
zene, alcohol, acetone, ether, ketones, thinners or gasoline, as
they can deform and discolor the case.
• If the instrument seems to be malfunctioning, confirm that the
batteries are not discharged, before contacting your dealer or
Hioki representative.
This manual contains information and warnings essential for safe op-
eration of the instrument and for maintaining it in safe operating con-
dition. Before using it, be sure to carefully read the following safety
precautions.
Safety Symbol
The following symbols in this manual indicate the relative impor-
tance of cautions and warnings.
Measurement categories (Overvoltage categories)
This instrument complies with CAT IV (600 V) safety requirements. To
ensure safe operation of measurement instruments, IEC 61010
establishes safety standards for various electrical environments, cate-
gorized as CAT I to CAT IV, and called measurement categories.
These are defined as follows.
CAT I : Secondary electrical circuits connected to an AC electrical
outlet through a transformer or similar device.
CAT II : Primary electrical circuits in equipment connected to an AC
electrical outlet by a power cord (portable tools, household appli-
ances, etc.)
CAT III :Primary electrical circuits of heavy equipment (fixed installa-
tions) connected directly to the distribution panel, and feeders from
the distribution panel to outlets.
CAT IV : The circuit from the service drop to the service entrance, and
to the power meter and primary overcurrent protection device (distri-
bution panel).
Higher-numbered catego-
ries correspond to electri-
cal environments with
greater momentary energy.
So a measurement device
designed for CAT III envi-
ronments can endure
greater momentary energy
than a device designed for
CAT II. Using a measurement instrument in an environment desig-
nated with a higher-numbered category than that for which the instru-
ment is rated could result in a severe accident, and must be carefully
avoided. Never use a CAT I measuring instrument in CAT II, III, or IV
environments. The measurement categories comply with the Over-
voltage Categories of the IEC60664 Standards.
Follow these precautions to ensure safe operation and to obtain the full
benefits of the various functions.
Performance Check and Voltage Detection
Safety
This instrument is designed to comply with IEC 61010
Safety Standards, and has been thoroughly tested for
safety prior to shipment. However, mishandling during
use could result in injury or death, as well as damage to
the instrument. Be certain that you understand the
instructions and precautions in the manual before use.
We disclaim any responsibility for accidents or injuries
not resulting directly from instrument defects.
HEAD OFFICE
81 Koizumi, Ueda, Nagano 386-1192, Japan
TEL [phone] / FAX [phone]
E-mail: [e-mail] URL http://www.hioki.com/
HIOKI USA CORPORATION
6 Corporate Drive, Cranbury, NJ 08512, USA
TEL [phone] / FAX [phone]
May 2008 Revised edition 3
Printed in Japan
3120A980-03 08-05H
Introduction
Thank you for purchasing the
HIOKI “Model 3120 VOLTAGE
DETECTOR.” To obtain maximum
performance from the instrument,
please read this manual first, and
keep it handy for future reference.
3120
VOLTAGE
DETECTOR
INSTRUCTION MANUAL
In the manual, the symbol indicates particularly important
information that the user should read before using the instrument.
The symbol printed on the instrument indicates that the user
should refer to a corresponding topic in the manual (marked with
the symbol) before using the relevant function.
Indicates a double-insulated device.
Indicates AC (Alternating Current).
Indicates that incorrect operation presents an extreme haz-
ard that could result in serious injury or death to the user.
Indicates that incorrect operation presents a significant haz-
ard that could result in serious injury or death to the user.
Indicates that incorrect operation presents a possibility of
injury to the user or damage to the device.
Indicates advisory items related to performance or correct
operation of the instrument.
Usage Notes
• This instrument is designed for use indoors. It can be operated
at temperatures between 0 and 40°C without degrading safety.
• This instrument is not designed to be entirely water- or dust-
proof. Do not use it in an especially dusty environment, nor
where it might be splashed with liquid. This may cause damage.
• To avoid damage to the instrument, protect it from physical
shock when transporting and handling. Be especially careful to
avoid physical shock from dropping.
A weak green light indicates dead battery. Replace the batteries im-
mediately.
Detection
The maximum rated voltage between input terminals and
ground is 600V AC. Attempting to measure voltages
exceeding 600V with respect to ground could damage the
instrument and result in personal injury.
• The green LED indicates battery consumption but is not a guar-
antee of the performance of the instrument. Be sure to check its
performance using a known power source (e.g., AC outlet) prior
to use.
• The 3120 voltage detector works using a live AC circuit. It will not
work using an earthed wire or neutral point. If there are several
lines, such as 2-phase wires and 3-phase wires, perform voltage
detection on each line separately.
• The 3120 cannot perform voltage detection on a shielded wire.
• Be sure to grip the 3120 firmly during measurement. But, do not
touch the portion beyond the barrier. It will not produce any
detection.
• Make sure the detecting element properly contacts the object to
be measured. (See the right figure.)
3120 VOLTAGE DETECTOR Object to be Measured
The red LED lights up and the
buzzer sounds. Live.
Only the green LED lights up. Not live or below the measurement-voltage
range (70 V or less).
Performance Check
Detection
The green LED is still lighting up..
OK
OK NG
2. Turn the switch ON.
(Turn it clockwise.)
3. Grip the 3120 firmly and apply the detecting
element to a known power supply
(e.g., AC outlet) in order to check the
performance.
Turn on the switch. In the state that the green LED
is lighting up, apply the detecting element to the ob-
ject to be measured. If there are several wires, con-
duct a voltage check of each wire separately. (Check
some points for bundle of wires.)
The object cannot perform voltage detec-
tion. (It is not live or the earth potential is
below the measurement-voltage range
(70 V or less).)
The green LED lights up. The green LED does not light up or is dim.
The batteries are running
The red LED lights up
and the buzzer sounds.
The red LED does not light up
or the buzzer does not sound.
The 3120 is operating
The 3120 may be malfunctioning.
properly. It can be used.
Do not use it.
The red LED lights up and the buzzer sounds.
The object is live.
Switch
1. Inspect the 3120 carefully to ensure that no damage.
There is no damage. The 3120 is damaged.
Be sure to check the following before use to avoid electrical
Contact your dealer or Hioki representative.
OK NG
×
Voltage detection is not
○
performed properly. it is parallel to the object.
Position the detecting element so that
Detecting
element
Barrier
The red LED and buzzer
sound are getting off.
low. Replace the batteries.
NG
NG
The batteries are running
low. Replace the batteries.
shock.
Replacing the batteries
• After replacing the batteries, replace the switch section
before using the instrument.
• To avoid the possibility of explosion, do not short circuit, dis-
assemble or incinerate batteries.
• Handle and dispose of batteries in accordance with local
regulations.
• Do not mix old and new batteries, or different types of bat-
teries. Also, be careful to observe battery polarity during
installation. Otherwise, poor performance or damage from
battery leakage could result.
• Use R03 manganese battery or LR03 alkaline battery.
• After use, always turn OFF the power.
Specifications
Basic Specifications
Measurement funcion Detection
Measurement voltage 70 to 600 VAC (when in contact with an IV2mm2
or equivalent insulated wire)
Measurement frequency 50/60 Hz
Pilot light The red LED lights up and the buzzer sounds
when the wire is live.
Battery check
The green LED is dim or out when the batteries are
low.
Power supply Two R03 manganese batteries or Two LR03
alkaline batteries.
Dimensions Approx. 149H ×φ18.5 mm (5.87”H × φ0.73”)
(excluding projections)
Mass Approx. 38 g (1.3 oz.)
(including two R03 manganese batteries)
Operating environment Indoors, altitude up to 2000 m (6562-ft.)
Operating temperature and
humidity range 0 to 40°C (32 to 104
°F ), 80%RH max.
(with no condensation)
Storage temperature and
humidity range -20 to 60°C (68 to 140
°F ), 80%RH max.
(with no condensation)
Accessories Instruction manual Two R03 manganese batteries (For monitor
built into the main unit)
Standards applying Safety
EMC
EN61010,Pollution degree2,
Measurement category IV 600 V
(anticipated transient overvoltage 8000 V)
UL1436:1998, CSA C22.2 No.160-M1985
EN61326
Electrical Specifications
Maximum rated voltage to earth600 VAC
Withstand voltage 6.88 kVrms
Rated supply voltage 1.5 VDC ×2
Operating supply-voltage range From 3.45 V to the voltage at which the green
LED goes out (central value: 2.1 V)
Maximum rated power 170 mW (Max) Power supply voltage 3.0 VDC
Rated power 27 mW (Typ) Power supply voltage 3.0 VDC
(Power ON Standby state)
Continuous operating time
R03 manganese batteries: Approx.100 hours
LR03 alkaline batteries : Approx.200 hours
(Power ON Standby state)
12
3
①
②
Turn the switch off. Press and hold down the switch, then turn it
counterclockwise to remove the switch section.
Replace the old battery with a new
4
Install the switch section back
into place by holding it down
Replacing the batteries
one. Confirm correct polarity when
installing the new battery. and turning clockwise.
This mark
should be
[ OFF ].

Overview
This noncontact type of voltage detector unit enables the hot-line
state of AC voltage to be checked through the wire or cable cover-
ing.
Initial Inspection
When you receive the instrument, inspect it carefully to ensure that no
damage occurred during shipping. If damage is evident, or if it fails to
operate according to the specifications, contact your dealer or Hioki rep-
resentative.
Maintenance and Service
• To clean the instrument, wipe it gently with a soft cloth moistened
with water or mild detergent. Never use solvents such as ben-
zene, alcohol, acetone, ether, ketones, thinners or gasoline, as
they can deform and discolor the case.
• If the instrument seems to be malfunctioning, confirm that the
batteries are not discharged, before contacting your dealer or
Hioki representative.
This manual contains information and warnings essential for safe op-
eration of the instrument and for maintaining it in safe operating con-
dition. Before using it, be sure to carefully read the following safety
precautions.
Safety Symbol
The following symbols in this manual indicate the relative impor-
tance of cautions and warnings.
Measurement categories (Overvoltage categories)
This instrument complies with CAT IV (600 V) safety requirements. To
ensure safe operation of measurement instruments, IEC 61010
establishes safety standards for various electrical environments, cate-
gorized as CAT I to CAT IV, and called measurement categories.
These are defined as follows.
CAT I : Secondary electrical circuits connected to an AC electrical
outlet through a transformer or similar device.
CAT II : Primary electrical circuits in equipment connected to an AC
electrical outlet by a power cord (portable tools, household appli-
ances, etc.)
CAT III :Primary electrical circuits of heavy equipment (fixed installa-
tions) connected directly to the distribution panel, and feeders from
the distribution panel to outlets.
CAT IV : The circuit from the service drop to the service entrance, and
to the power meter and primary overcurrent protection device (distri-
bution panel).
Higher-numbered catego-
ries correspond to electri-
cal environments with
greater momentary energy.
So a measurement device
designed for CAT III envi-
ronments can endure
greater momentary energy
than a device designed for
CAT II. Using a measurement instrument in an environment desig-
nated with a higher-numbered category than that for which the instru-
ment is rated could result in a severe accident, and must be carefully
avoided. Never use a CAT I measuring instrument in CAT II, III, or IV
environments. The measurement categories comply with the Over-
voltage Categories of the IEC60664 Standards.
Follow these precautions to ensure safe operation and to obtain the full
benefits of the various functions.
Performance Check and Voltage Detection
Safety
This instrument is designed to comply with IEC 61010
Safety Standards, and has been thoroughly tested for
safety prior to shipment. However, mishandling during
use could result in injury or death, as well as damage to
the instrument. Be certain that you understand the
instructions and precautions in the manual before use.
We disclaim any responsibility for accidents or injuries
not resulting directly from instrument defects.
HEAD OFFICE
81 Koizumi, Ueda, Nagano 386-1192, Japan
TEL [phone] / FAX [phone]
E-mail: [e-mail] URL http://www.hioki.com/
HIOKI USA CORPORATION
6 Corporate Drive, Cranbury, NJ 08512, USA
TEL [phone] / FAX [phone]
May 2008 Revised edition 3
Printed in Japan
3120A980-03 08-05H
Introduction
Thank you for purchasing the
HIOKI “Model 3120 VOLTAGE
DETECTOR.” To obtain maximum
performance from the instrument,
please read this manual first, and
keep it handy for future reference.
3120
VOLTAGE
DETECTOR
INSTRUCTION MANUAL
In the manual, the symbol indicates particularly important
information that the user should read before using the instrument.
The symbol printed on the instrument indicates that the user
should refer to a corresponding topic in the manual (marked with
the symbol) before using the relevant function.
Indicates a double-insulated device.
Indicates AC (Alternating Current).
Indicates that incorrect operation presents an extreme haz-
ard that could result in serious injury or death to the user.
Indicates that incorrect operation presents a significant haz-
ard that could result in serious injury or death to the user.
Indicates that incorrect operation presents a possibility of
injury to the user or damage to the device.
Indicates advisory items related to performance or correct
operation of the instrument.
Usage Notes
• This instrument is designed for use indoors. It can be operated
at temperatures between 0 and 40°C without degrading safety.
• This instrument is not designed to be entirely water- or dust-
proof. Do not use it in an especially dusty environment, nor
where it might be splashed with liquid. This may cause damage.
• To avoid damage to the instrument, protect it from physical
shock when transporting and handling. Be especially careful to
avoid physical shock from dropping.
A weak green light indicates dead battery. Replace the batteries im-
mediately.
Detection
The maximum rated voltage between input terminals and
ground is 600V AC. Attempting to measure voltages
exceeding 600V with respect to ground could damage the
instrument and result in personal injury.
• The green LED indicates battery consumption but is not a guar-
antee of the performance of the instrument. Be sure to check its
performance using a known power source (e.g., AC outlet) prior
to use.
• The 3120 voltage detector works using a live AC circuit. It will not
work using an earthed wire or neutral point. If there are several
lines, such as 2-phase wires and 3-phase wires, perform voltage
detection on each line separately.
• The 3120 cannot perform voltage detection on a shielded wire.
• Be sure to grip the 3120 firmly during measurement. But, do not
touch the portion beyond the barrier. It will not produce any
detection.
• Make sure the detecting element properly contacts the object to
be measured. (See the right figure.)
3120 VOLTAGE DETECTOR Object to be Measured
The red LED lights up and the
buzzer sounds. Live.
Only the green LED lights up. Not live or below the measurement-voltage
range (70 V or less).
Performance Check
Detection
The green LED is still lighting up..
OK
OK NG
2. Turn the switch ON.
(Turn it clockwise.)
3. Grip the 3120 firmly and apply the detecting
element to a known power supply
(e.g., AC outlet) in order to check the
performance.
Turn on the switch. In the state that the green LED
is lighting up, apply the detecting element to the ob-
ject to be measured. If there are several wires, con-
duct a voltage check of each wire separately. (Check
some points for bundle of wires.)
The object cannot perform voltage detec-
tion. (It is not live or the earth potential is
below the measurement-voltage range
(70 V or less).)
The green LED lights up. The green LED does not light up or is dim.
The batteries are running
The red LED lights up
and the buzzer sounds.
The red LED does not light up
or the buzzer does not sound.
The 3120 is operating
The 3120 may be malfunctioning.
properly. It can be used.
Do not use it.
The red LED lights up and the buzzer sounds.
The object is live.
Switch
1. Inspect the 3120 carefully to ensure that no damage.
There is no damage. The 3120 is damaged.
Be sure to check the following before use to avoid electrical
Contact your dealer or Hioki representative.
OK NG
×
Voltage detection is not
○
performed properly. it is parallel to the object.
Position the detecting element so that
Detecting
element
Barrier
The red LED and buzzer
sound are getting off.
low. Replace the batteries.
NG
NG
The batteries are running
low. Replace the batteries.
shock.
Replacing the batteries
• After replacing the batteries, replace the switch section
before using the instrument.
• To avoid the possibility of explosion, do not short circuit, dis-
assemble or incinerate batteries.
• Handle and dispose of batteries in accordance with local
regulations.
• Do not mix old and new batteries, or different types of bat-
teries. Also, be careful to observe battery polarity during
installation. Otherwise, poor performance or damage from
battery leakage could result.
• Use R03 manganese battery or LR03 alkaline battery.
• After use, always turn OFF the power.
Specifications
Basic Specifications
Measurement funcion Detection
Measurement voltage 70 to 600 VAC (when in contact with an IV2mm2
or equivalent insulated wire)
Measurement frequency 50/60 Hz
Pilot light The red LED lights up and the buzzer sounds
when the wire is live.
Battery check
The green LED is dim or out when the batteries are
low.
Power supply Two R03 manganese batteries or Two LR03
alkaline batteries.
Dimensions Approx. 149H ×φ18.5 mm (5.87”H × φ0.73”)
(excluding projections)
Mass Approx. 38 g (1.3 oz.)
(including two R03 manganese batteries)
Operating environment Indoors, altitude up to 2000 m (6562-ft.)
Operating temperature and
humidity range 0 to 40°C (32 to 104
°F ), 80%RH max.
(with no condensation)
Storage temperature and
humidity range -20 to 60°C (68 to 140
°F ), 80%RH max.
(with no condensation)
Accessories Instruction manual Two R03 manganese batteries (For monitor
built into the main unit)
Standards applying Safety
EMC
EN61010,Pollution degree2,
Measurement category IV 600 V
(anticipated transient overvoltage 8000 V)
UL1436:1998, CSA C22.2 No.160-M1985
EN61326
Electrical Specifications
Maximum rated voltage to earth600 VAC
Withstand voltage 6.88 kVrms
Rated supply voltage 1.5 VDC ×2
Operating supply-voltage range From 3.45 V to the voltage at which the green
LED goes out (central value: 2.1 V)
Maximum rated power 170 mW (Max) Power supply voltage 3.0 VDC
Rated power 27 mW (Typ) Power supply voltage 3.0 VDC
(Power ON Standby state)
Continuous operating time
R03 manganese batteries: Approx.100 hours
LR03 alkaline batteries : Approx.200 hours
(Power ON Standby state)
12
3
①
②
Turn the switch off. Press and hold down the switch, then turn it
counterclockwise to remove the switch section.
Replace the old battery with a new
4
Install the switch section back
into place by holding it down
Replacing the batteries
one. Confirm correct polarity when
installing the new battery. and turning clockwise.
This mark
should be
[ OFF ].

Overview
This noncontact type of voltage detector unit enables the hot-line
state of AC voltage to be checked through the wire or cable cover-
ing.
Initial Inspection
When you receive the instrument, inspect it carefully to ensure that no
damage occurred during shipping. If damage is evident, or if it fails to
operate according to the specifications, contact your dealer or Hioki rep-
resentative.
Maintenance and Service
• To clean the instrument, wipe it gently with a soft cloth moistened
with water or mild detergent. Never use solvents such as ben-
zene, alcohol, acetone, ether, ketones, thinners or gasoline, as
they can deform and discolor the case.
• If the instrument seems to be malfunctioning, confirm that the
batteries are not discharged, before contacting your dealer or
Hioki representative.
This manual contains information and warnings essential for safe op-
eration of the instrument and for maintaining it in safe operating con-
dition. Before using it, be sure to carefully read the following safety
precautions.
Safety Symbol
The following symbols in this manual indicate the relative impor-
tance of cautions and warnings.
Measurement categories (Overvoltage categories)
This instrument complies with CAT IV (600 V) safety requirements. To
ensure safe operation of measurement instruments, IEC 61010
establishes safety standards for various electrical environments, cate-
gorized as CAT I to CAT IV, and called measurement categories.
These are defined as follows.
CAT I : Secondary electrical circuits connected to an AC electrical
outlet through a transformer or similar device.
CAT II : Primary electrical circuits in equipment connected to an AC
electrical outlet by a power cord (portable tools, household appli-
ances, etc.)
CAT III :Primary electrical circuits of heavy equipment (fixed installa-
tions) connected directly to the distribution panel, and feeders from
the distribution panel to outlets.
CAT IV : The circuit from the service drop to the service entrance, and
to the power meter and primary overcurrent protection device (distri-
bution panel).
Higher-numbered catego-
ries correspond to electri-
cal environments with
greater momentary energy.
So a measurement device
designed for CAT III envi-
ronments can endure
greater momentary energy
than a device designed for
CAT II. Using a measurement instrument in an environment desig-
nated with a higher-numbered category than that for which the instru-
ment is rated could result in a severe accident, and must be carefully
avoided. Never use a CAT I measuring instrument in CAT II, III, or IV
environments. The measurement categories comply with the Over-
voltage Categories of the IEC60664 Standards.
Follow these precautions to ensure safe operation and to obtain the full
benefits of the various functions.
Performance Check and Voltage Detection
Safety
This instrument is designed to comply with IEC 61010
Safety Standards, and has been thoroughly tested for
safety prior to shipment. However, mishandling during
use could result in injury or death, as well as damage to
the instrument. Be certain that you understand the
instructions and precautions in the manual before use.
We disclaim any responsibility for accidents or injuries
not resulting directly from instrument defects.
HEAD OFFICE
81 Koizumi, Ueda, Nagano 386-1192, Japan
TEL [phone] / FAX [phone]
E-mail: [email protected] URL http://www.hioki.com/
HIOKI USA CORPORATION
6 Corporate Drive, Cranbury, NJ 08512, USA
TEL [phone] / FAX [phone]
May 2008 Revised edition 3
Printed in Japan
3120A980-03 08-05H
Introduction
Thank you for purchasing the
HIOKI “Model 3120 VOLTAGE
DETECTOR.” To obtain maximum
performance from the instrument,
please read this manual first, and
keep it handy for future reference.
3120
VOLTAGE
DETECTOR
INSTRUCTION MANUAL
In the manual, the symbol indicates particularly important
information that the user should read before using the instrument.
The symbol printed on the instrument indicates that the user
should refer to a corresponding topic in the manual (marked with
the symbol) before using the relevant function.
Indicates a double-insulated device.
Indicates AC (Alternating Current).
Indicates that incorrect operation presents an extreme haz-
ard that could result in serious injury or death to the user.
Indicates that incorrect operation presents a significant haz-
ard that could result in serious injury or death to the user.
Indicates that incorrect operation presents a possibility of
injury to the user or damage to the device.
Indicates advisory items related to performance or correct
operation of the instrument.
Usage Notes
• This instrument is designed for use indoors. It can be operated
at temperatures between 0 and 40°C without degrading safety.
• This instrument is not designed to be entirely water- or dust-
proof. Do not use it in an especially dusty environment, nor
where it might be splashed with liquid. This may cause damage.
• To avoid damage to the instrument, protect it from physical
shock when transporting and handling. Be especially careful to
avoid physical shock from dropping.
A weak green light indicates dead battery. Replace the batteries im-
mediately.
Detection
The maximum rated voltage between input terminals and
ground is 600V AC. Attempting to measure voltages
exceeding 600V with respect to ground could damage the
instrument and result in personal injury.
• The green LED indicates battery consumption but is not a guar-
antee of the performance of the instrument. Be sure to check its
performance using a known power source (e.g., AC outlet) prior
to use.
• The 3120 voltage detector works using a live AC circuit. It will not
work using an earthed wire or neutral point. If there are several
lines, such as 2-phase wires and 3-phase wires, perform voltage
detection on each line separately.
• The 3120 cannot perform voltage detection on a shielded wire.
• Be sure to grip the 3120 firmly during measurement. But, do not
touch the portion beyond the barrier. It will not produce any
detection.
• Make sure the detecting element properly contacts the object to
be measured. (See the right figure.)
3120 VOLTAGE DETECTOR Object to be Measured
The red LED lights up and the
buzzer sounds. Live.
Only the green LED lights up. Not live or below the measurement-voltage
range (70 V or less).
Performance Check
Detection
The green LED is still lighting up..
OK
OK NG
2. Turn the switch ON.
(Turn it clockwise.)
3. Grip the 3120 firmly and apply the detecting
element to a known power supply
(e.g., AC outlet) in order to check the
performance.
Turn on the switch. In the state that the green LED
is lighting up, apply the detecting element to the ob-
ject to be measured. If there are several wires, con-
duct a voltage check of each wire separately. (Check
some points for bundle of wires.)
The object cannot perform voltage detec-
tion. (It is not live or the earth potential is
below the measurement-voltage range
(70 V or less).)
The green LED lights up. The green LED does not light up or is dim.
The batteries are running
The red LED lights up
and the buzzer sounds.
The red LED does not light up
or the buzzer does not sound.
The 3120 is operating
The 3120 may be malfunctioning.
properly. It can be used.
Do not use it.
The red LED lights up and the buzzer sounds.
The object is live.
Switch
1. Inspect the 3120 carefully to ensure that no damage.
There is no damage. The 3120 is damaged.
Be sure to check the following before use to avoid electrical
Contact your dealer or Hioki representative.
OK NG
×
Voltage detection is not
○
performed properly. it is parallel to the object.
Position the detecting element so that
Detecting
element
Barrier
The red LED and buzzer
sound are getting off.
low. Replace the batteries.
NG
NG
The batteries are running
low. Replace the batteries.
shock.
Replacing the batteries
• After replacing the batteries, replace the switch section
before using the instrument.
• To avoid the possibility of explosion, do not short circuit, dis-
assemble or incinerate batteries.
• Handle and dispose of batteries in accordance with local
regulations.
• Do not mix old and new batteries, or different types of bat-
teries. Also, be careful to observe battery polarity during
installation. Otherwise, poor performance or damage from
battery leakage could result.
• Use R03 manganese battery or LR03 alkaline battery.
• After use, always turn OFF the power.
Specifications
Basic Specifications
Measurement funcion Detection
Measurement voltage 70 to 600 VAC (when in contact with an IV2mm2
or equivalent insulated wire)
Measurement frequency 50/60 Hz
Pilot light The red LED lights up and the buzzer sounds
when the wire is live.
Battery check
The green LED is dim or out when the batteries are
low.
Power supply Two R03 manganese batteries or Two LR03
alkaline batteries.
Dimensions Approx. 149H ×φ18.5 mm (5.87”H × φ0.73”)
(excluding projections)
Mass Approx. 38 g (1.3 oz.)
(including two R03 manganese batteries)
Operating environment Indoors, altitude up to 2000 m (6562-ft.)
Operating temperature and
humidity range 0 to 40°C (32 to 104
°F ), 80%RH max.
(with no condensation)
Storage temperature and
humidity range -20 to 60°C (68 to 140
°F ), 80%RH max.
(with no condensation)
Accessories Instruction manual Two R03 manganese batteries (For monitor
built into the main unit)
Standards applying Safety
EMC
EN61010,Pollution degree2,
Measurement category IV 600 V
(anticipated transient overvoltage 8000 V)
UL1436:1998, CSA C22.2 No.160-M1985
EN61326
Electrical Specifications
Maximum rated voltage to earth600 VAC
Withstand voltage 6.88 kVrms
Rated supply voltage 1.5 VDC ×2
Operating supply-voltage range From 3.45 V to the voltage at which the green
LED goes out (central value: 2.1 V)
Maximum rated power 170 mW (Max) Power supply voltage 3.0 VDC
Rated power 27 mW (Typ) Power supply voltage 3.0 VDC
(Power ON Standby state)
Continuous operating time
R03 manganese batteries: Approx.100 hours
LR03 alkaline batteries : Approx.200 hours
(Power ON Standby state)
12
3
①
②
Turn the switch off. Press and hold down the switch, then turn it
counterclockwise to remove the switch section.
Replace the old battery with a new
4
Install the switch section back
into place by holding it down
Replacing the batteries
one. Confirm correct polarity when
installing the new battery. and turning clockwise.
This mark
should be
[ OFF ].

Overview
This noncontact type of voltage detector unit enables the hot-line
state of AC voltage to be checked through the wire or cable cover-
ing.
Initial Inspection
When you receive the instrument, inspect it carefully to ensure that no
damage occurred during shipping. If damage is evident, or if it fails to
operate according to the specifications, contact your dealer or Hioki rep-
resentative.
Maintenance and Service
• To clean the instrument, wipe it gently with a soft cloth moistened
with water or mild detergent. Never use solvents such as ben-
zene, alcohol, acetone, ether, ketones, thinners or gasoline, as
they can deform and discolor the case.
• If the instrument seems to be malfunctioning, confirm that the
batteries are not discharged, before contacting your dealer or
Hioki representative.
This manual contains information and warnings essential for safe op-
eration of the instrument and for maintaining it in safe operating con-
dition. Before using it, be sure to carefully read the following safety
precautions.
Safety Symbol
The following symbols in this manual indicate the relative impor-
tance of cautions and warnings.
Measurement categories (Overvoltage categories)
This instrument complies with CAT IV (600 V) safety requirements. To
ensure safe operation of measurement instruments, IEC 61010
establishes safety standards for various electrical environments, cate-
gorized as CAT I to CAT IV, and called measurement categories.
These are defined as follows.
CAT I : Secondary electrical circuits connected to an AC electrical
outlet through a transformer or similar device.
CAT II : Primary electrical circuits in equipment connected to an AC
electrical outlet by a power cord (portable tools, household appli-
ances, etc.)
CAT III :Primary electrical circuits of heavy equipment (fixed installa-
tions) connected directly to the distribution panel, and feeders from
the distribution panel to outlets.
CAT IV : The circuit from the service drop to the service entrance, and
to the power meter and primary overcurrent protection device (distri-
bution panel).
Higher-numbered catego-
ries correspond to electri-
cal environments with
greater momentary energy.
So a measurement device
designed for CAT III envi-
ronments can endure
greater momentary energy
than a device designed for
CAT II. Using a measurement instrument in an environment desig-
nated with a higher-numbered category than that for which the instru-
ment is rated could result in a severe accident, and must be carefully
avoided. Never use a CAT I measuring instrument in CAT II, III, or IV
environments. The measurement categories comply with the Over-
voltage Categories of the IEC60664 Standards.
Follow these precautions to ensure safe operation and to obtain the full
benefits of the various functions.
Performance Check and Voltage Detection
Safety
This instrument is designed to comply with IEC 61010
Safety Standards, and has been thoroughly tested for
safety prior to shipment. However, mishandling during
use could result in injury or death, as well as damage to
the instrument. Be certain that you understand the
instructions and precautions in the manual before use.
We disclaim any responsibility for accidents or injuries
not resulting directly from instrument defects.
HEAD OFFICE
81 Koizumi, Ueda, Nagano 386-1192, Japan
TEL [phone] / FAX [phone]
E-mail: [email protected] URL http://www.hioki.com/
HIOKI USA CORPORATION
6 Corporate Drive, Cranbury, NJ 08512, USA
TEL [phone] / FAX [phone]
May 2008 Revised edition 3
Printed in Japan
3120A980-03 08-05H
Introduction
Thank you for purchasing the
HIOKI “Model 3120 VOLTAGE
DETECTOR.” To obtain maximum
performance from the instrument,
please read this manual first, and
keep it handy for future reference.
3120
VOLTAGE
DETECTOR
INSTRUCTION MANUAL
In the manual, the symbol indicates particularly important
information that the user should read before using the instrument.
The symbol printed on the instrument indicates that the user
should refer to a corresponding topic in the manual (marked with
the symbol) before using the relevant function.
Indicates a double-insulated device.
Indicates AC (Alternating Current).
Indicates that incorrect operation presents an extreme haz-
ard that could result in serious injury or death to the user.
Indicates that incorrect operation presents a significant haz-
ard that could result in serious injury or death to the user.
Indicates that incorrect operation presents a possibility of
injury to the user or damage to the device.
Indicates advisory items related to performance or correct
operation of the instrument.
Usage Notes
• This instrument is designed for use indoors. It can be operated
at temperatures between 0 and 40°C without degrading safety.
• This instrument is not designed to be entirely water- or dust-
proof. Do not use it in an especially dusty environment, nor
where it might be splashed with liquid. This may cause damage.
• To avoid damage to the instrument, protect it from physical
shock when transporting and handling. Be especially careful to
avoid physical shock from dropping.
A weak green light indicates dead battery. Replace the batteries im-
mediately.
Detection
The maximum rated voltage between input terminals and
ground is 600V AC. Attempting to measure voltages
exceeding 600V with respect to ground could damage the
instrument and result in personal injury.
• The green LED indicates battery consumption but is not a guar-
antee of the performance of the instrument. Be sure to check its
performance using a known power source (e.g., AC outlet) prior
to use.
• The 3120 voltage detector works using a live AC circuit. It will not
work using an earthed wire or neutral point. If there are several
lines, such as 2-phase wires and 3-phase wires, perform voltage
detection on each line separately.
• The 3120 cannot perform voltage detection on a shielded wire.
• Be sure to grip the 3120 firmly during measurement. But, do not
touch the portion beyond the barrier. It will not produce any
detection.
• Make sure the detecting element properly contacts the object to
be measured. (See the right figure.)
3120 VOLTAGE DETECTOR Object to be Measured
The red LED lights up and the
buzzer sounds. Live.
Only the green LED lights up. Not live or below the measurement-voltage
range (70 V or less).
Performance Check
Detection
The green LED is still lighting up..
OK
OK NG
2. Turn the switch ON.
(Turn it clockwise.)
3. Grip the 3120 firmly and apply the detecting
element to a known power supply
(e.g., AC outlet) in order to check the
performance.
Turn on the switch. In the state that the green LED
is lighting up, apply the detecting element to the ob-
ject to be measured. If there are several wires, con-
duct a voltage check of each wire separately. (Check
some points for bundle of wires.)
The object cannot perform voltage detec-
tion. (It is not live or the earth potential is
below the measurement-voltage range
(70 V or less).)
The green LED lights up. The green LED does not light up or is dim.
The batteries are running
The red LED lights up
and the buzzer sounds.
The red LED does not light up
or the buzzer does not sound.
The 3120 is operating
The 3120 may be malfunctioning.
properly. It can be used.
Do not use it.
The red LED lights up and the buzzer sounds.
The object is live.
Switch
1. Inspect the 3120 carefully to ensure that no damage.
There is no damage. The 3120 is damaged.
Be sure to check the following before use to avoid electrical
Contact your dealer or Hioki representative.
OK NG
×
Voltage detection is not
○
performed properly. it is parallel to the object.
Position the detecting element so that
Detecting
element
Barrier
The red LED and buzzer
sound are getting off.
low. Replace the batteries.
NG
NG
The batteries are running
low. Replace the batteries.
shock.
Replacing the batteries
• After replacing the batteries, replace the switch section
before using the instrument.
• To avoid the possibility of explosion, do not short circuit, dis-
assemble or incinerate batteries.
• Handle and dispose of batteries in accordance with local
regulations.
• Do not mix old and new batteries, or different types of bat-
teries. Also, be careful to observe battery polarity during
installation. Otherwise, poor performance or damage from
battery leakage could result.
• Use R03 manganese battery or LR03 alkaline battery.
• After use, always turn OFF the power.
Specifications
Basic Specifications
Measurement funcion Detection
Measurement voltage 70 to 600 VAC (when in contact with an IV2mm2
or equivalent insulated wire)
Measurement frequency 50/60 Hz
Pilot light The red LED lights up and the buzzer sounds
when the wire is live.
Battery check
The green LED is dim or out when the batteries are
low.
Power supply Two R03 manganese batteries or Two LR03
alkaline batteries.
Dimensions Approx. 149H ×φ18.5 mm (5.87”H × φ0.73”)
(excluding projections)
Mass Approx. 38 g (1.3 oz.)
(including two R03 manganese batteries)
Operating environment Indoors, altitude up to 2000 m (6562-ft.)
Operating temperature and
humidity range 0 to 40°C (32 to 104
°F ), 80%RH max.
(with no condensation)
Storage temperature and
humidity range -20 to 60°C (68 to 140
°F ), 80%RH max.
(with no condensation)
Accessories Instruction manual Two R03 manganese batteries (For monitor
built into the main unit)
Standards applying Safety
EMC
EN61010,Pollution degree2,
Measurement category IV 600 V
(anticipated transient overvoltage 8000 V)
UL1436:1998, CSA C22.2 No.160-M1985
EN61326
Electrical Specifications
Maximum rated voltage to earth600 VAC
Withstand voltage 6.88 kVrms
Rated supply voltage 1.5 VDC ×2
Operating supply-voltage range From 3.45 V to the voltage at which the green
LED goes out (central value: 2.1 V)
Maximum rated power 170 mW (Max) Power supply voltage 3.0 VDC
Rated power 27 mW (Typ) Power supply voltage 3.0 VDC
(Power ON Standby state)
Continuous operating time
R03 manganese batteries: Approx.100 hours
LR03 alkaline batteries : Approx.200 hours
(Power ON Standby state)
12
3
①
②
Turn the switch off. Press and hold down the switch, then turn it
counterclockwise to remove the switch section.
Replace the old battery with a new
4
Install the switch section back
into place by holding it down
Replacing the batteries
one. Confirm correct polarity when
installing the new battery. and turning clockwise.
This mark
should be
[ OFF ].

Overview
This noncontact type of voltage detector unit enables the hot-line
state of AC voltage to be checked through the wire or cable cover-
ing.
Initial Inspection
When you receive the instrument, inspect it carefully to ensure that no
damage occurred during shipping. If damage is evident, or if it fails to
operate according to the specifications, contact your dealer or Hioki rep-
resentative.
Maintenance and Service
• To clean the instrument, wipe it gently with a soft cloth moistened
with water or mild detergent. Never use solvents such as ben-
zene, alcohol, acetone, ether, ketones, thinners or gasoline, as
they can deform and discolor the case.
• If the instrument seems to be malfunctioning, confirm that the
batteries are not discharged, before contacting your dealer or
Hioki representative.
This manual contains information and warnings essential for safe op-
eration of the instrument and for maintaining it in safe operating con-
dition. Before using it, be sure to carefully read the following safety
precautions.
Safety Symbol
The following symbols in this manual indicate the relative impor-
tance of cautions and warnings.
Measurement categories (Overvoltage categories)
This instrument complies with CAT IV (600 V) safety requirements. To
ensure safe operation of measurement instruments, IEC 61010
establishes safety standards for various electrical environments, cate-
gorized as CAT I to CAT IV, and called measurement categories.
These are defined as follows.
CAT I : Secondary electrical circuits connected to an AC electrical
outlet through a transformer or similar device.
CAT II : Primary electrical circuits in equipment connected to an AC
electrical outlet by a power cord (portable tools, household appli-
ances, etc.)
CAT III :Primary electrical circuits of heavy equipment (fixed installa-
tions) connected directly to the distribution panel, and feeders from
the distribution panel to outlets.
CAT IV : The circuit from the service drop to the service entrance, and
to the power meter and primary overcurrent protection device (distri-
bution panel).
Higher-numbered catego-
ries correspond to electri-
cal environments with
greater momentary energy.
So a measurement device
designed for CAT III envi-
ronments can endure
greater momentary energy
than a device designed for
CAT II. Using a measurement instrument in an environment desig-
nated with a higher-numbered category than that for which the instru-
ment is rated could result in a severe accident, and must be carefully
avoided. Never use a CAT I measuring instrument in CAT II, III, or IV
environments. The measurement categories comply with the Over-
voltage Categories of the IEC60664 Standards.
Follow these precautions to ensure safe operation and to obtain the full
benefits of the various functions.
Performance Check and Voltage Detection
Safety
This instrument is designed to comply with IEC 61010
Safety Standards, and has been thoroughly tested for
safety prior to shipment. However, mishandling during
use could result in injury or death, as well as damage to
the instrument. Be certain that you understand the
instructions and precautions in the manual before use.
We disclaim any responsibility for accidents or injuries
not resulting directly from instrument defects.
HEAD OFFICE
81 Koizumi, Ueda, Nagano 386-1192, Japan
TEL [phone] / FAX [phone]
E-mail: [email protected] URL http://www.hioki.com/
HIOKI USA CORPORATION
6 Corporate Drive, Cranbury, NJ 08512, USA
TEL [phone] / FAX [phone]
May 2008 Revised edition 3
Printed in Japan
3120A980-03 08-05H
Introduction
Thank you for purchasing the
HIOKI “Model 3120 VOLTAGE
DETECTOR.” To obtain maximum
performance from the instrument,
please read this manual first, and
keep it handy for future reference.
3120
VOLTAGE
DETECTOR
INSTRUCTION MANUAL
In the manual, the symbol indicates particularly important
information that the user should read before using the instrument.
The symbol printed on the instrument indicates that the user
should refer to a corresponding topic in the manual (marked with
the symbol) before using the relevant function.
Indicates a double-insulated device.
Indicates AC (Alternating Current).
Indicates that incorrect operation presents an extreme haz-
ard that could result in serious injury or death to the user.
Indicates that incorrect operation presents a significant haz-
ard that could result in serious injury or death to the user.
Indicates that incorrect operation presents a possibility of
injury to the user or damage to the device.
Indicates advisory items related to performance or correct
operation of the instrument.
Usage Notes
• This instrument is designed for use indoors. It can be operated
at temperatures between 0 and 40°C without degrading safety.
• This instrument is not designed to be entirely water- or dust-
proof. Do not use it in an especially dusty environment, nor
where it might be splashed with liquid. This may cause damage.
• To avoid damage to the instrument, protect it from physical
shock when transporting and handling. Be especially careful to
avoid physical shock from dropping.
A weak green light indicates dead battery. Replace the batteries im-
mediately.
Detection
The maximum rated voltage between input terminals and
ground is 600V AC. Attempting to measure voltages
exceeding 600V with respect to ground could damage the
instrument and result in personal injury.
• The green LED indicates battery consumption but is not a guar-
antee of the performance of the instrument. Be sure to check its
performance using a known power source (e.g., AC outlet) prior
to use.
• The 3120 voltage detector works using a live AC circuit. It will not
work using an earthed wire or neutral point. If there are several
lines, such as 2-phase wires and 3-phase wires, perform voltage
detection on each line separately.
• The 3120 cannot perform voltage detection on a shielded wire.
• Be sure to grip the 3120 firmly during measurement. But, do not
touch the portion beyond the barrier. It will not produce any
detection.
• Make sure the detecting element properly contacts the object to
be measured. (See the right figure.)
3120 VOLTAGE DETECTOR Object to be Measured
The red LED lights up and the
buzzer sounds. Live.
Only the green LED lights up. Not live or below the measurement-voltage
range (70 V or less).
Performance Check
Detection
The green LED is still lighting up..
OK
OK NG
2. Turn the switch ON.
(Turn it clockwise.)
3. Grip the 3120 firmly and apply the detecting
element to a known power supply
(e.g., AC outlet) in order to check the
performance.
Turn on the switch. In the state that the green LED
is lighting up, apply the detecting element to the ob-
ject to be measured. If there are several wires, con-
duct a voltage check of each wire separately. (Check
some points for bundle of wires.)
The object cannot perform voltage detec-
tion. (It is not live or the earth potential is
below the measurement-voltage range
(70 V or less).)
The green LED lights up. The green LED does not light up or is dim.
The batteries are running
The red LED lights up
and the buzzer sounds.
The red LED does not light up
or the buzzer does not sound.
The 3120 is operating
The 3120 may be malfunctioning.
properly. It can be used.
Do not use it.
The red LED lights up and the buzzer sounds.
The object is live.
Switch
1. Inspect the 3120 carefully to ensure that no damage.
There is no damage. The 3120 is damaged.
Be sure to check the following before use to avoid electrical
Contact your dealer or Hioki representative.
OK NG
×
Voltage detection is not
○
performed properly. it is parallel to the object.
Position the detecting element so that
Detecting
element
Barrier
The red LED and buzzer
sound are getting off.
low. Replace the batteries.
NG
NG
The batteries are running
low. Replace the batteries.
shock.
Replacing the batteries
• After replacing the batteries, replace the switch section
before using the instrument.
• To avoid the possibility of explosion, do not short circuit, dis-
assemble or incinerate batteries.
• Handle and dispose of batteries in accordance with local
regulations.
• Do not mix old and new batteries, or different types of bat-
teries. Also, be careful to observe battery polarity during
installation. Otherwise, poor performance or damage from
battery leakage could result.
• Use R03 manganese battery or LR03 alkaline battery.
• After use, always turn OFF the power.
Specifications
Basic Specifications
Measurement funcion Detection
Measurement voltage 70 to 600 VAC (when in contact with an IV2mm2
or equivalent insulated wire)
Measurement frequency 50/60 Hz
Pilot light The red LED lights up and the buzzer sounds
when the wire is live.
Battery check
The green LED is dim or out when the batteries are
low.
Power supply Two R03 manganese batteries or Two LR03
alkaline batteries.
Dimensions Approx. 149H ×φ18.5 mm (5.87”H × φ0.73”)
(excluding projections)
Mass Approx. 38 g (1.3 oz.)
(including two R03 manganese batteries)
Operating environment Indoors, altitude up to 2000 m (6562-ft.)
Operating temperature and
humidity range 0 to 40°C (32 to 104
°F ), 80%RH max.
(with no condensation)
Storage temperature and
humidity range -20 to 60°C (68 to 140
°F ), 80%RH max.
(with no condensation)
Accessories Instruction manual Two R03 manganese batteries (For monitor
built into the main unit)
Standards applying Safety
EMC
EN61010,Pollution degree2,
Measurement category IV 600 V
(anticipated transient overvoltage 8000 V)
UL1436:1998, CSA C22.2 No.160-M1985
EN61326
Electrical Specifications
Maximum rated voltage to earth600 VAC
Withstand voltage 6.88 kVrms
Rated supply voltage 1.5 VDC ×2
Operating supply-voltage range From 3.45 V to the voltage at which the green
LED goes out (central value: 2.1 V)
Maximum rated power 170 mW (Max) Power supply voltage 3.0 VDC
Rated power 27 mW (Typ) Power supply voltage 3.0 VDC
(Power ON Standby state)
Continuous operating time
R03 manganese batteries: Approx.100 hours
LR03 alkaline batteries : Approx.200 hours
(Power ON Standby state)
12
3
①
②
Turn the switch off. Press and hold down the switch, then turn it
counterclockwise to remove the switch section.
Replace the old battery with a new
4
Install the switch section back
into place by holding it down
Replacing the batteries
one. Confirm correct polarity when
installing the new battery. and turning clockwise.
This mark
should be
[ OFF ].

Overview
This noncontact type of voltage detector unit enables the hot-line
state of AC voltage to be checked through the wire or cable cover-
ing.
Initial Inspection
When you receive the instrument, inspect it carefully to ensure that no
damage occurred during shipping. If damage is evident, or if it fails to
operate according to the specifications, contact your dealer or Hioki rep-
resentative.
Maintenance and Service
• To clean the instrument, wipe it gently with a soft cloth moistened
with water or mild detergent. Never use solvents such as ben-
zene, alcohol, acetone, ether, ketones, thinners or gasoline, as
they can deform and discolor the case.
• If the instrument seems to be malfunctioning, confirm that the
batteries are not discharged, before contacting your dealer or
Hioki representative.
This manual contains information and warnings essential for safe op-
eration of the instrument and for maintaining it in safe operating con-
dition. Before using it, be sure to carefully read the following safety
precautions.
Safety Symbol
The following symbols in this manual indicate the relative impor-
tance of cautions and warnings.
Measurement categories (Overvoltage categories)
This instrument complies with CAT IV (600 V) safety requirements. To
ensure safe operation of measurement instruments, IEC 61010
establishes safety standards for various electrical environments, cate-
gorized as CAT I to CAT IV, and called measurement categories.
These are defined as follows.
CAT I : Secondary electrical circuits connected to an AC electrical
outlet through a transformer or similar device.
CAT II : Primary electrical circuits in equipment connected to an AC
electrical outlet by a power cord (portable tools, household appli-
ances, etc.)
CAT III :Primary electrical circuits of heavy equipment (fixed installa-
tions) connected directly to the distribution panel, and feeders from
the distribution panel to outlets.
CAT IV : The circuit from the service drop to the service entrance, and
to the power meter and primary overcurrent protection device (distri-
bution panel).
Higher-numbered catego-
ries correspond to electri-
cal environments with
greater momentary energy.
So a measurement device
designed for CAT III envi-
ronments can endure
greater momentary energy
than a device designed for
CAT II. Using a measurement instrument in an environment desig-
nated with a higher-numbered category than that for which the instru-
ment is rated could result in a severe accident, and must be carefully
avoided. Never use a CAT I measuring instrument in CAT II, III, or IV
environments. The measurement categories comply with the Over-
voltage Categories of the IEC60664 Standards.
Follow these precautions to ensure safe operation and to obtain the full
benefits of the various functions.
Performance Check and Voltage Detection
Safety
This instrument is designed to comply with IEC 61010
Safety Standards, and has been thoroughly tested for
safety prior to shipment. However, mishandling during
use could result in injury or death, as well as damage to
the instrument. Be certain that you understand the
instructions and precautions in the manual before use.
We disclaim any responsibility for accidents or injuries
not resulting directly from instrument defects.
HEAD OFFICE
81 Koizumi, Ueda, Nagano 386-1192, Japan
TEL [phone] / FAX [phone]
E-mail: [email protected] URL http://www.hioki.com/
HIOKI USA CORPORATION
6 Corporate Drive, Cranbury, NJ 08512, USA
TEL [phone] / FAX [phone]
May 2008 Revised edition 3
Printed in Japan
3120A980-03 08-05H
Introduction
Thank you for purchasing the
HIOKI “Model 3120 VOLTAGE
DETECTOR.” To obtain maximum
performance from the instrument,
please read this manual first, and
keep it handy for future reference.
3120
VOLTAGE
DETECTOR
INSTRUCTION MANUAL
In the manual, the symbol indicates particularly important
information that the user should read before using the instrument.
The symbol printed on the instrument indicates that the user
should refer to a corresponding topic in the manual (marked with
the symbol) before using the relevant function.
Indicates a double-insulated device.
Indicates AC (Alternating Current).
Indicates that incorrect operation presents an extreme haz-
ard that could result in serious injury or death to the user.
Indicates that incorrect operation presents a significant haz-
ard that could result in serious injury or death to the user.
Indicates that incorrect operation presents a possibility of
injury to the user or damage to the device.
Indicates advisory items related to performance or correct
operation of the instrument.
Usage Notes
• This instrument is designed for use indoors. It can be operated
at temperatures between 0 and 40°C without degrading safety.
• This instrument is not designed to be entirely water- or dust-
proof. Do not use it in an especially dusty environment, nor
where it might be splashed with liquid. This may cause damage.
• To avoid damage to the instrument, protect it from physical
shock when transporting and handling. Be especially careful to
avoid physical shock from dropping.
A weak green light indicates dead battery. Replace the batteries im-
mediately.
Detection
The maximum rated voltage between input terminals and
ground is 600V AC. Attempting to measure voltages
exceeding 600V with respect to ground could damage the
instrument and result in personal injury.
• The green LED indicates battery consumption but is not a guar-
antee of the performance of the instrument. Be sure to check its
performance using a known power source (e.g., AC outlet) prior
to use.
• The 3120 voltage detector works using a live AC circuit. It will not
work using an earthed wire or neutral point. If there are several
lines, such as 2-phase wires and 3-phase wires, perform voltage
detection on each line separately.
• The 3120 cannot perform voltage detection on a shielded wire.
• Be sure to grip the 3120 firmly during measurement. But, do not
touch the portion beyond the barrier. It will not produce any
detection.
• Make sure the detecting element properly contacts the object to
be measured. (See the right figure.)
3120 VOLTAGE DETECTOR Object to be Measured
The red LED lights up and the
buzzer sounds. Live.
Only the green LED lights up. Not live or below the measurement-voltage
range (70 V or less).
Performance Check
Detection
The green LED is still lighting up..
OK
OK NG
2. Turn the switch ON.
(Turn it clockwise.)
3. Grip the 3120 firmly and apply the detecting
element to a known power supply
(e.g., AC outlet) in order to check the
performance.
Turn on the switch. In the state that the green LED
is lighting up, apply the detecting element to the ob-
ject to be measured. If there are several wires, con-
duct a voltage check of each wire separately. (Check
some points for bundle of wires.)
The object cannot perform voltage detec-
tion. (It is not live or the earth potential is
below the measurement-voltage range
(70 V or less).)
The green LED lights up. The green LED does not light up or is dim.
The batteries are running
The red LED lights up
and the buzzer sounds.
The red LED does not light up
or the buzzer does not sound.
The 3120 is operating
The 3120 may be malfunctioning.
properly. It can be used.
Do not use it.
The red LED lights up and the buzzer sounds.
The object is live.
Switch
1. Inspect the 3120 carefully to ensure that no damage.
There is no damage. The 3120 is damaged.
Be sure to check the following before use to avoid electrical
Contact your dealer or Hioki representative.
OK NG
×
Voltage detection is not
○
performed properly. it is parallel to the object.
Position the detecting element so that
Detecting
element
Barrier
The red LED and buzzer
sound are getting off.
low. Replace the batteries.
NG
NG
The batteries are running
low. Replace the batteries.
shock.
Replacing the batteries
• After replacing the batteries, replace the switch section
before using the instrument.
• To avoid the possibility of explosion, do not short circuit, dis-
assemble or incinerate batteries.
• Handle and dispose of batteries in accordance with local
regulations.
• Do not mix old and new batteries, or different types of bat-
teries. Also, be careful to observe battery polarity during
installation. Otherwise, poor performance or damage from
battery leakage could result.
• Use R03 manganese battery or LR03 alkaline battery.
• After use, always turn OFF the power.
Specifications
Basic Specifications
Measurement funcion Detection
Measurement voltage 70 to 600 VAC (when in contact with an IV2mm2
or equivalent insulated wire)
Measurement frequency 50/60 Hz
Pilot light The red LED lights up and the buzzer sounds
when the wire is live.
Battery check
The green LED is dim or out when the batteries are
low.
Power supply Two R03 manganese batteries or Two LR03
alkaline batteries.
Dimensions Approx. 149H ×φ18.5 mm (5.87”H × φ0.73”)
(excluding projections)
Mass Approx. 38 g (1.3 oz.)
(including two R03 manganese batteries)
Operating environment Indoors, altitude up to 2000 m (6562-ft.)
Operating temperature and
humidity range 0 to 40°C (32 to 104
°F ), 80%RH max.
(with no condensation)
Storage temperature and
humidity range -20 to 60°C (68 to 140
°F ), 80%RH max.
(with no condensation)
Accessories Instruction manual Two R03 manganese batteries (For monitor
built into the main unit)
Standards applying Safety
EMC
EN61010,Pollution degree2,
Measurement category IV 600 V
(anticipated transient overvoltage 8000 V)
UL1436:1998, CSA C22.2 No.160-M1985
EN61326
Electrical Specifications
Maximum rated voltage to earth600 VAC
Withstand voltage 6.88 kVrms
Rated supply voltage 1.5 VDC ×2
Operating supply-voltage range From 3.45 V to the voltage at which the green
LED goes out (central value: 2.1 V)
Maximum rated power 170 mW (Max) Power supply voltage 3.0 VDC
Rated power 27 mW (Typ) Power supply voltage 3.0 VDC
(Power ON Standby state)
Continuous operating time
R03 manganese batteries: Approx.100 hours
LR03 alkaline batteries : Approx.200 hours
(Power ON Standby state)
12
3
①
②
Turn the switch off. Press and hold down the switch, then turn it
counterclockwise to remove the switch section.
Replace the old battery with a new
4
Install the switch section back
into place by holding it down
Replacing the batteries
one. Confirm correct polarity when
installing the new battery. and turning clockwise.
This mark
should be
[ OFF ].