Safety Standards
Measuring Instruments
The Long-Awaited Bench-type Model Is Here !
Leakage Current Measurement Essential
for Electrical Safety
Because of the risks it poses, many standards stipulate leak
current test methods, the performance of test equipment, limits
for leak current, and other factors related to leak current. The
bench-type 3156 LEAK CURRENT HiTESTER by itself, without
any additional equipment, is capable of performing tests that
comply with standards for a wide range of equipment, from
general purpose electrical equipment to medical electrical
equipment. The 3156 also is equipped with functions and an
interface that support embedded test lines.
HIOKI company overview, new products, environmental considerations and
other information are available on our website.
Automatically compatible with Networks
stipulated by IEC/UL/JIS standards
In order to avoid dangers such as electric shock,
electrical equipment is designed so that those
portions that are likely to be touched by people
are insulated from the power source. However,
the insulation resistance is not infinite, so there is
always some leak current present. Furthermore,
the extent of the leak current changes over time
as the insulation deteriorates. To determine their
safety level, the 3156 LEAK CURRENT HiTESTER
can prove to be highly valuable, both as a tester
on the production line as well as a maintenance
and inspection tool.
Main Features
■ Standard support for a variety of Networks
The 3156 is engineered to automatically support the
"Networks" (human simulated resistance) stipulated by
the various international safety standards. Switch
between Networks or use the filters using a PC.
■ Measurement that complies with standards
The 3156 by itself can measure leak current in compliance
with IEC, UL, and JIS standards.
■ Automatic measurement function
■ RS-232C, GP-IB, and EXT I/O interfaces
The 3156 is capable of automatically measuring power
supply polarity switching as well as the normal state/single
failure state, and can display the maximum values. The
measurement time and the wait time can be set by the user.
Because the 3156 is equipped with several standard
interfaces, it is easy to set up for automatic inspection on
a production line, etc. In addition, the RS-232C port can
be used to connect the optional 9442 Printer for easy
■ Stores data for 100 units
The 3156 can store data such as equipment name, control
number, ground class, and measured values for up to 100
pieces of equipment being tested.
■ Save up to 30 sets of measuring conditions
The 3156 can save and load up to 30 different sets of
measuring conditions, and can switch between different
sets quickly.
■ Power supply separation
The power supply for the 3156 is separate from the line
power supply of the equipment being tested, preventing
damage to equipment due to wrong supply voltage being
Simple operation in an interactive format
The 3156 is equipped with a touch panel that can
be used to make settings simply by touching the
items to be selected on the display, making
operation even more simple.
110% voltage application terminals
The 110% voltage application terminals are used when testing
medical equipment. It outputs on a 1:1 basis the voltage that is
supplied to the line power supply for the equipment being
tested. The polarity of the connectors can be switched.
Measurement mode
Breaker for equipment being tested
Since the 3156 is a bench-type unit that is suited
embedded test lines, it is equipped with a terminal
board and breaker on the front panel, allowing
test equipment to be easily connected to the 3156
even when it is rack mounted.
● Leakage current between enclosure and line
● Leakage current between enclosure and earth
● Leakage current between enclosure and enclosure
● Earth leakage current
● Patient leakage current I
● Patient leakage current II
● Patient leakage current III
● Patient auxiliary current
Based on the settings for the Network and
the equipment being tested, the 3156 displays
the appropriate measurement mode. The
state of the settable keys can be seen at a
glance. All settings can be made by selecting
the appropriate items or values.
[Initial screen]
■ Wiring check functions
■ Support for proprietary networks
The 3156 performs polarity
checks and VA checks.
When making measurements on a proprietary network that is
not built into the 3156, the
3156 can be used as a true
effective value ammeter in the
1MHz band.
■ Browsing saved data
The 3156 allows the user to
browse all saved data. Saved
data can also be printed out
or downloaded to a computer.
[System screen]
Result of evaluation against tolerance setting
Maximum value display
Current measured value
Displays the power supply failure status
and the maximum value for the leak current
as it fluctuates due to the operation of the
equipment being tested.
Data storage
Power supply polarity/equipment
status/measured current
Measurement data: For up to 100 units
Measuring conditions: Up to 30 sets
Allowable value
The upper limit for tolerance is set according
to the standard. The set value can be changed
freely, if necessary.
[Measurement screen]
Single failure setting
The single failure status can be set for
individual items in automatic testing, with
continuous testing performed automatically
only for the items for which the single failure
setting was made. In addition, the wait time
and measurement time can also be set.
Leak current measurement
for general equipment
The network (human simulated resistance) is
specified separately in each standard, and when
taking measurements a network that is suited to
the standards is needed. The 3156 is pre-engineered
with basic Networks that correspond to each
IEC standard
[ IEC 60990, others ]
UL standard
[ UL471, UL1310, UL1437, others ]
JIS standard
The standard numbers that are listed are only examples.
The networks listed below can be used with all applicable
[ JIS B8561, others ]
Network types
For JIS standards
For IEC60990s
Basic measuring element
Basic measuring element
Basic measuring element
General purpose 1
For UL standards
Basic measuring element
Filter on
Filter 1 on
General purpose 2
Filter 2 on
Basic measuring element
Leak current measurement
for medical equipment
Medical equipment leak current includes not only
ground leak current and exterior leak current, but
also patient leak current (I to III) and patient
measured current. The 3156 can measure all of
these different types of leak current without any
additional equipment.
IEC standard
[ IEC 60601-1 ('88) + am1 ('91) + am2 ('95) ]
UL standard
[ UL 2601-1, others ]
The 3156 does not have a built-in
insulated transformer. When
medical equipment, use a step-up insulated transformer or other
device to provide 110% of the rated voltage as the line power
supply for the equipment being tested.
The standard numbers that are listed are only examples. The
JIS standard
[ JIS T 0601-1, others ]
Leak current types and Network types
For medical equipment
Medical equipment leak current types
Faulty medical equipment
Faulty medical equipment
Signal input section
Medical equipment
Patient leakage
current III
Patient leakage
current II
Basic measuring element
Patient leakage
current I
Earth leakage current
Enclosure leakage
Earth leakage current
A current flowing from the power supply through the interior or surface of
the insulation to the protective ground line.
Enclosure leakage current
A current flowing from a part of the enclosure which during normal use can be
touched by an operator or patient either to ground or to another part of the
enclosure, through an external conductor other than the protective ground.
Patient leakage current
A current flowing from the device through the patient to ground.
Patient auxiliary current
A current flowing between contacts which during
normal use are connected through the patient, with
no intended physiological effect.
Filter on
Separation of the power supply for the 3156 and
the line for the equipment being tested
The power supply voltage for the 3156 does not need to
be changed, even if the supply voltage for the equipment
being tested is different. The difference can be managed
by controlling the line supply voltage for the equipment
being tested. This helps prevent malfunctions due to the
wrong voltage being input for the 3156 power supply.
Main unit (3156)
power supply
Line power supply
100 to 240V (50/60Hz)
External control through EXT I/O
The start of measurement and the loading of the measuring
conditions can be controlled externally. The evaluation
results, test signals, etc., can also be output externally,
permitting the construction of an automated line.
Contents of EXT I/O
● Outputs
Active low signal
Input signal
Voltage input to the EXT.DCV terminal
applied voltage
Voltage input to the EXT.DCV
High level
terminal, or open
Low level
0.3V DC or less
Output signal
Open collector output
Maximum load
output current
24V DC (when not using the
EXT.DCV terminal)
60mA DC per signal
(when low level)
In addition to outputting evaluation results for each
measurement item, the T-FAIL output is provided for
continued output after one FAIL during automatic testing.
: Continues to output a low signal during automatic measurement
: Outputs the count when measuring multiple items during
automatic measurement
: Outputs the evaluation result "PASS" for individual items
during automatic measurement
: Outputs the evaluation result "FAIL" for individual items
during automatic measurement
: Continues output even if a FAIL occurs during automatic testing.
: Internal 5V DC output (not insulated from internal circuitry)
: Internal GND output (identical to rack grounded GND level)
● Inputs
: Starts automatic measurement when low
: Forcibly ends measurement when low
LOAD (0 to 4): Loads a saved panel (30 panels)
: Zero adjust signal (valid only in ground leak current mode)
EXT.DCV : External power supply input (5V to 24V DC)
EXT.COM : External COM input
External control through a PC
Includes RS-232C interface and GP-IB interface as
standard. These can be used to control the functions of
the 3156 through a PC, and to collect measurement
■ RS-232C interface
Transfer method: Start-stop synchronization, full-duplex
Transfer speed : 9600 fixed
Data length
: 8 bits
Stop bit
Parity bit
: None
: None
: Not used
: D-sub 9-pin male
■ GP-IB interface
Compliant standards: IEEE-488.1 1987,
Refer to IEEE-488.2 1987
: D-sub 24 pin female
Data printout
Data can be printed out on the optional 9442 Printer by
using the RS-232C interface connector. This is useful
for attaching inspection data, etc.
9442 Printer
Printing method: Thermal serial dot printing
Paper width/printing speed: 112 mm/52.5cps
Power supply: 9443 AC Adapter, or NiMH
battery provided (charge with the 9443; can print
approximately 3000 characters with a full charge)
Dimensions: Approx. 160(W)×66.5(H)×170 (D) mm
Mass: Approx. 580g
* Connecting the 9442 requires either the 9444 Connecting Cable or the AC adapter.
Printout contents
(The printed items can be selected from among the items listed below.)
● Measurement date
● Equipment name
● Control number
● Class (mounting section)
● Network
● Measurement mode
● Filter setting
● Tolerance
● Maximum value
● Evaluation result
● Measured current
(AC, DC, AC+DC, AC peak)
● Power supply polarity
(normal phase, reverse phase)
● Equipment status
(normal, not grounded)
3156 Specifications
■ Leak current measurement
Measurement mode : Earth leakage current / Leakage current between
enclosure and earth / Leakage current between
enclosure and enclosure / Leakage current between
enclosure and line / Patient leakage current I /
Patient leakage current II / Patient leakage current
III / Patient auxiliary current
: DC, AC, AC+DC, AC peak
Target current
: 25 mA max. (DC/AC/AC+DC mode)
Allowable value
measurement current
75 mA max. (ACpeak mode)
Measurement range : DC/AC/AC+DC mode:
50 µA/500 µA/5 mA/25 mA
AC peak mode:
500 µA/1 mA /10 mA/75 mA
: Auto range/Hold range
Range switch
: Manual: Automatic generation of internal trigger,
Trigger system
and free-run measurement
Automatic: measurement started by external
start signal
1. Started by pressing Start key on the
operation screen.
2. Asserted by the START terminal on
the EXT I/O connector.
3. Started by the :START interface
Measurement speed : Trigger-system manual measurement: 100 ±1 ms
(indication of moving average of 16 measurements)
Trigger-system automatic measurement:
100 ±1 ms (min.) - measurement setting time
: Terminal T1, terminal T2 (with built-in fuse holder)
Terminal T3 (110% voltage application terminal)
: Indication of a current value calculated based
the measured drop in voltage caused by simulated
resistance of the human body.
Measurement of true effective value.
The measurement section: chassis-grounded and
A/D conversion system : ∆ ∑ system (20 bits)
Input resistance : 1 MΩ ±1% (single-ended input)
Excluding voltmeter section, simulated resistance
of the human body (current detection circuit)
: 200 pF or lower (between terminals T1 and T2)
Input capacity
(f = 100 kHz, with network circuit isolated)
Grounding capacity : 200 pF or lower(between terminals T1/T2 and chassis)
: 60 dB or higher, at 60 Hz, 10 kHz
(between terminals T1/T2
40 dB or higher, at 100 kHz, 1 MHz
and chassis)
■ Network (human simulated resistance)
● For medical electrical equipment
: Basic measurement element: 1 kΩ
Filter: 10 kΩ + 15 nF
● For IEC 60990 : Basic measurement element: 1.5 kΩ + 500 Ω
Filter 1: 10 kΩ + 22 nF
Filter 2: 10 kΩ + (20 kΩ+ 6.2 nF) // 9.1 nF
● For JIS
: Basic measurement element: 1 kΩ
Filter: 10 kΩ + 11.22 nF + 579 Ω
● For UL
: Basic measurement element: 1.5 kΩ // 0.15 µF
● General-purpose 1: Basic measurement element : 1 kΩ
● General-purpose 2: Basic measurement element : 2 kΩ
■ Functions
: Equipped with a voltage output terminal (T3) that applies
110% power supply voltage between the functionally
insulated signal input/output section (or Type F applied
part) and ground.
Output ON/OFF selection
Output impedance: 22.5 ±1 kΩ
•Applied when positive phase (to input power supply voltage)
•Applied when negative phase (to input power supply voltage)
Automatic switching function (automatic measurement function)
Wiring check function : Polarity check/VA check
Automatic measurement : Setting of measuring time.
Setting of delay (wait) time for changing setting conditions.
The power supply polarity and equipment status are
automatically switched during measurement.
: Use of T2 and internal contact/Use of T1 and T2
Application line
selection function
: Pre-check of current value between connection terminals to
Ground fault
prevention function
prevent a ground fault. Only effective for leakage current
measurement between enclosure and line.
: •Setting of malfunction mode for power line for
Setting of singlefault condition
sample equipment.
1. Disconnection of one wire in power line (neutral side)
2. Disconnection of protective earth conductor
•Application of 110% voltage for simulated connection of
malfunctioning equipment.
Positive phase/negative phase
•Selection of application line for leakage current
measurement between enclosure and line.
Power line for sample : Positive/negative phase
equipment (switching
(Automatic switching possible when using automatic
power supply polarity)
measurement function)
Setting of measuring : Setting range: 1 sec. to 5 min., in 1-sec. increments
Effective only in automatic measurement
Measurement delay : Setting range: 1 sec. to 30 min., in 1-sec. increments
(setting) function
•Wait time from the completion of measurement to
power supply disconnection
•Wait time from switching power supply polarity to
the start of measurement
•Wait time for operations other than switching polarity
Maximum value hold : Effective in all measurement modes
110% voltage
application function
: Allowable value: Sets the upper-limit current value
Judgement: PASS measurement value ≤ upper-limit value
FAIL measurement value > upper-limit value
Processing: Indication, buzzer, judgement output from
: •Current measurement function
Mode selection
Unit of current measurement: Auto/ mA, fixed
•Voltage measurement function
Isolates the internal network for using the product as a
voltmeter between terminals T1 and T2.
Maximum measurement voltage: 25 V
Beep sound setting : •Allowable value judgement
•Key input
•T3 (110% voltage application terminal) output
•Line voltage output from T2
Save/load function : 30 panels for saving the following setting data
(measurement mode, network, equipment name, control
number, grounding class, applied part, measurement
range, filter, target current, allowable value setting,
malfunction condition setting, power supply polarity
switching, automatic measurement items, automatic
measuring time, measurement delay time)
: Saved content: Sample equipment information (equipment
Data save function
name, control number), measurement data, date
Memory capacity: Data on up to 100 units
: Auto calendar, automatic leap-year adjustment, 24Clock function
hour clock
Clock accuracy: Deviation of about 4 minutes a month
: SRAM (test condition data), RTC
Data backup
Backup battery life: 4 years (reference value at 25ºC)
Backlight automatic : Constant ON/Auto OFF
OFF function
1 min. to 30 min., in 1-min. increments
: MEM (internal RAM)/KEY (6 × 6 matrix touch panel)/
Self-test function
LCD (front LCD panel)/LED /Buzzer
: Japanese or English
Language setting
: Clears all data including measurement conditions and
System reset
measurement data.
Clears all saved measurement data.
Clears all saved condition setting data including panels.
Allowable value
judgement function
■ Accuracy (Current measurement )
■ Operating temperature and humidity for guaranteed accuracy: 23 ± 5 ºC, 80%rh or lower (no condensation)
■ Temperature coefficient: 0.1 x basic accuracy x (T-23) weighted --- operating temperature T (ºC)
■ Warm-up time: 30 min.
■ Value calculated based on voltage detected at terminals of Network having non-inductive resistance of 1 kΩ
(theoretical value).
■ Measurements in voltmeter mode conform to the following accuracy level.
● Measurement of DC
● Measurement of AC* , AC+DC
Guaranteed Measurement
accuracy range resolution
25.00 mA
4 mA or more
10 µA
5.000 mA
400 µA or more
1 µA
500.0 µA
40 µA or more
0.1 µA
50.00 µA
4 µA or more
0.01 µA
DC < f ≤ 100kHz
100kHz < f ≤ 1MHz
● Measurement of AC Peak*2
75.0 mA
10.00 mA
Guaranteed Measurement
accuracy range resolution
8mA or more
0.8mA or more
100 µA
10 µA
1kHz < f ≤ 10kHz
100 µA or more
1 µA
40 µA or more
0.1 µA
4 mA or more
10 µA
5.000 mA
400 µA or more
1 µA
500.0 µA
40 µA or more
0.1 µA
50.00 µA
4 µA or more
0.01 µA
● Power supply voltage monitor accuracy
Guaranteed Measurement
accuracy range resolution
300.0 V
85 Vor more*
0.1 V
(measurement method: average value response, effective value conversion)
20Hz < f ≤ 1kHz
1.000 mA
25.00 mA
● Current consumption monitor accuracy
500.0 µA
Guaranteed Measurement
accuracy range resolution
Guaranteed Measurement
accuracy range resolution
16 A
0.5Aor more*
0.1 A
*1: Weighted with frequency characteristic (fc = 4 Hz) of high-pass filter.
*2: Cannot be set when network A , B and C(filter off) is selected.
*3: "less than 80 V" is indicated for a value less than 80 V.
*4: "less than 0.5 A" is indicated for a value less than 0.5 A.
■ General Specifications
Display section
Operation section
Operating temperature
and humidity
Storage temperature
and humidity
Calibration Period
Operating Environment
Power source for
main unit
: 320 × 240 dot matrix LCD (with backlight)
: 6 × 6 matrix touch panel
: 0 to 40 ºC , 80%rh or less (no condensation)
Applicable Standards : EMC: EN61326:1997+A1:1998+A2:2001
Safety: EN61010-1:2001
EN61010-2-031:1994 Pollution Degree 2
Terminals T1, T2: Measurement category II
(Anticipated Transient Overvoltage: 2.5 kV)
Terminal T3: Measurement category I
(Anticipated Transient Overvoltage: 1.5 kV)
: 16%f.s. at 3 V
Effect of conducted
(typical value for measurement in AC 500 mA range)
electromagnetic field
: 9170 TEST LEAD 2 sets, 9195 ENCLOSURE
PROBE 1, 9399 CARRYING CASE 1, Alligator
clips 3 (2 red, 1 black), AC power cord 2 (for
main unit, for power line of sample equipment),
Spare fuse 2 (for main unit power supply 250V
T0.1AL, for measurement operation 250V
: Approx. 320W × 110H × 263D mm
: Approx. 4.0kg
: -10 to 50 ºC, 80%rh or less (no condensation)
: 6 months
: Indoors, <2000 m ASL
: 100, 120, 220, 240 VAC (default setting)
Rated power source frequency: 50/60 Hz
Rated power: 30 VA
Power line for sample : 100 to 240 VAC
equipment and power Rated power source frequency: 50/60 Hz
Rated power: 1,500 VA
Power output maximum : 25 mA
allowable leakage current
Withstand voltage : [All power supply terminals] - [Protective earthing]
1.35 kV AC (5 mA), 1 min.
[All measurement terminals] - [All power supply terminals]
2.30 kV AC (5 mA), 1 min
[All measurement terminals] - [Control circuit]
2.30 kV AC (5 mA), 1 min
● Options
9637 RS-232C CABLE (9-pin to 9-pin., crossing cable,1.8m)
9638 RS-232C CABLE (9-pin to 25-pin., crossing cable,1.8m)
9151-02 GP-IB CABLE (2 m)
9151-04 GP-IB CABLE (4 m)
9443-01 AC ADAPTER (for printer, for use in Japan)
9443-02 AC ADAPTER (for printer, for use in EU)
9443-03 AC ADAPTER (for printer, for use in U.S.)
(Standard accessory)
(Standard accessory/2 set)
(Standard accessory)
9444 CONNECTION CABLE (for printer)
1196 RECORDING PAPER (for printer)
9686 CARRYING CASE (with casters)
81 Koizumi, Ueda, Nagano, 386-1192, Japan
TEL +81-268-28-0562 / FAX +81-268-28-0568
E-mail: os-com@
6 Corporate Drive, Cranbury, NJ 08512 USA
TEL +1-609-409-9109 / FAX +1-609-409-9108
E-mail: hioki@
Shanghai Representative Office :
1704 Shanghai Times Square Office
93 Huaihai Zhong Road
Shanghai, 200021, P.R.China
TEL +86-21-6391-0090, 0092
FAX +86-21-6391-0360
E-mail: [email protected]
All information correct as of Jun. 20, 2003. All specifications are subject to change without notice.
Printed in Japan