[1] SAFETY PRECAUTIONS Before use, read the following safety precautions.
This instruction manual explains how to safely use your new
DG36a insulation resistance tester. Before use, please readthis manual thoroughly. After reading it, keep it together withthe product so you can refer to it when necessary.
If this product is not used as specified in this manual, theprotection function of this product may be compromised.
Instructions given under the “ WARNING” and “ CAUTION”
headings must be followed to prevent accidental burns orelectrical shock.
1-1 Explanation of Warning Symbols
The meanings of the symbols used in this manual and on the
product are as follows.
Very important instruction for safe use.
The warning messages are intended to prevent accidents
to operating personnel such as burn and electrical shock.
The caution messages are intended to prevent damage tothe instrument.
High-voltage warming. (High voltage is generated fromtest pins.): Direct current (DC): Ground〜 : Alternating current (AC): Double insulation (Protection Class II)
LINE/: Line/Plus input (Red)EARTH/: Earth/Minus input (Black)
1-2 Warning Instruction for Safe Use
WARNINGTo ensure that you use the instrument safely, be sure toobserve the instructions.
1. Never use the instrument on electric circuits that
Exceed 3.6 kVA.
2. Pay special attention when measuring voltages of AC 33
Vrms (46.7 V peak) or DC 70 V or more to avoid injury.
3. The clamp sensor provided with this instrument is
exclusively for low-voltage use. Perform clamp current
measurement with 600 V or less lines.
4. When measuring insulation resistance, disconnect thepower supply of the device being measured.
5. Since high voltage (250 V/125 V/50 V) is generated
during the measurement of insulation resistance, be
careful about electric shock.
6. To avoid electric shock, always be sure to discharge thehigh voltage charged in the measured device after
measuring insulation resistance.
7. Never apply an input signal exceeding the maximum
rating input value.

8. Never use the instrument to measure a line connected toequipment (i.e. motors) that generates induced or surge
voltage since it may exceed the maximum allowable voltage.
9. Never use the instrument if the main unit or test leads aredamaged or broken.
10. Never use the instrument when it is not in its case.
11. Always keep your fingers behind the finger guards on
the probe and the clamp sensor barrier when taking
measurements.
12. Be sure to disconnect the test pins from the circuit whenchanging the function.
13. Before starting measurement, make sure that thefunction and range are properly set in accordance withthe measurement.
14. Never touch the instrument with wet hands or use it in adamp environment.
15. When insulation resistance is measured, measurement
voltage is generated from the black test probe connectedto the ground side, so do not touch the test pin.
16. When measuring insulation resistance, first connect theblack test probe to the ground side of the device being
measured and then connect the red test probe to the line
side. When disconnecting them, first remove the red test
probe on the line side and then remove the black test
probe on the ground side.
17. Never open the instrument case except when replacing
batteries. Do not try to alter the original specifications.
18. To ensure safety and maintain accuracy, calibrate andcheck the instrument at least once a year.
19. The instrument is for indoor use only.
CAUTION
1. When insulation resistance is being measured, themeasurement terminal of this instrument generates highvoltage. It is recommended that devices and parts (suchas semiconductors) with low or unknown withstanding
voltage be disconnected from the electric wiring (circuit)
before it is measured. This is particularly important withcomputer-related devices.
2. When measuring insulation resistance, set the value ofthe rated measurement voltage as close to the working
voltage of the circuit being measured as possible.
Example: With a 100 V circuit, use a rated measurement
voltage of 125 V.

− 1 −Test pins[4] DESCRIPTION OF FUNCTIONS

Removable
test pin covers

Battery
compartment
cover fixing
screwsBattery
compartment
cover

When notcoveredFinger guards
Test probe (red)Test probe (black)3-2 Display
Not used with this instrument
Measurement
REL
voltage generation
measurement

Low battery
indication
Data holdoperationDCmeasurement
NegativepolarityACmeasurement

WARNING
When canceling an operation, do not turn the function
switch during measurement.

4-2 MΩ START/STOP Button (MΩ Function)
Each time the START/STOP button is pressed in the MΩfunction, the mode switches in the order of the MΩmeasurement voltage generation & MΩ measurement mode
J the MΩ measurement voltage stop & measurement value
data hold mode J the MΩ measurement voltage generation& MΩ measurement mode J ....
I n t h e M Ω m e a s u re m e n t v o l t a g e g e n e r a t i o n & M Ω
measurement mode,
is illuminated on the display and theselected measurement voltage is generated.
In the MΩ measurement voltage stop & measurement value
data hold mode, the measurement voltage is stopped and themeasurement value is maintained. “ ” is illuminated on thedisplay.
Notes:• The MΩ measurement voltage generation mode
automatically stops after about 30 seconds. Should this be
the case, the measurement value will not be held.
• W h e n t h e m e a s u re m e n t f u n c t i o n i s s w i t c h e d , t h emeasurement value data hold is canceled.
4-3 AC/DC Button (V · CLAMP A Positions)
Each time this button is pressed in the V or CLAMP A
position, the measurement function switches in the order of
AC J DC J AC J ….
4-4 REL Button (DCV · ACV · DCA · ACA Functions)
When the DCV, ACV, DCA or ACA function is activated, press
this button. “ ” and “ ” will be illuminated on the display,
and the measurement value will be set using the input value
at the time the button was pressed as a reference. To cancel
this mode, press the button again and keep it depressed formore than 2 seconds.
Ex.) Display after the REL button is pressed during DC 100 V
input
Actual input value
DC 0120 V
DC 0100 V
DC 0090 V

Decimal points
Numerical indication

Measurement unit

− 5 −1. Never apply an external voltage on the input terminal.
2. Do not turn the function switch during measurement.
3. Do not hold the test probe by a section closer to the test
pin side behind the finger guard.
4. When the measured object has capacitance, it may
remain charged by the applied voltage from this
instrument for some time after measurement iscompleted. Be careful.

MΩMax. rating
input value
40.00 MΩ

Measurementrange
40.00 MΩ1) Applications: Measuring the insulation resistance (MΩ)
of electrical equipment and circuits.
2) Measurement procedure
1 Set the function switch to the desired measurement
voltage range of MΩ.
2 Short-circuit the test pins on the red and black test
probes, then press the MΩ START/STOP button toconfirm that the test leads are connected (displayed
value: 3 counts or less).
3 Turn off the power of the device you are going tomeasure.
4 Connect the black test probe (provided, with theblack clip connected) to the ground line of thedevice you are going to measure.
5 Connect the red test probe to the other end of theline of the device being measured.
6 Press the MΩ START/STOP button. The measurement
voltage will be applied between the test leads, andMΩ measurement will start. Measurement time isabout 30 seconds. Once that time has elapsed, theapplication of the measurement voltage will stop
automatically. Measurement can be stopped at any
time by pressing the MΩ START/STOP button again.
The measurement value will be fixed at the value
when the button was pressed.
− 9 −Display in REL measurement
DC 0020 V
DC 0000 V
DC –0010 V[3] NAME OF COMPONENT UNITS
Maximum rating Maximum overload
input value
protection input

3-1 Multimeter

DC/AC 600 V'LVSOD\

LINE (Red)40 MΩ
50 V/125 V/250 V EARTH (Black)
DCA · ACA

Clamp
sensorsection

DC/AC 600 V

Voltage and current
input prohibited

250 V AC
(50/60 Hz)
30 sec.

DC/AC 100 A

100 A DC/AC[2] APPLICATION AND FEATURES
2-1 Applications
Integrating the measurement functions demanded at electrical worksites, including insulation resistance measurement, DC/AC clamp
current measurement and DC/AC voltage measurement into a single
unit, this instrument is a compact insulation resistance tester withclamp sensor ideal for electrical work.

To perform the MΩ measurement again, press theMΩ START STOP button again.
8 After the measurement is complete, release the pinof the red test probe from the device that wasmeasured.
9 Release the black test probe from the ground line ofthe device that was measured.
10 Be sure to set the function switch to the OFF position
after completing measurement.
②3RZHU2))

③

⑤
⑥

⑦

①
⑨

④

A numerical value appears in the display before theMΩ START/STOP button is pressed (before themeasurement voltage is applied). This is not a
malfunction, and the displayed value is irrelevant to
the measurement.
During insulation resistance measurement, the leastsignificant digit of the displayed measurement value
may sometimes flicker.
During insulation resistance measurement, use therated measurement voltage that’s as close as
possible to the voltage used by the circuit being
measured.
Example: Use the rated measurement voltage of 125
V for an electrical circuit of 100 V.

− 10 −

1. This section is very important for safety. Read andunderstand the following instructions fully and maintainyour instrument properly.
2. The instrument must be calibrated and inspected atleast once a year to maintain its safety and accuracy.
6-1 Maintenance and Inspection
1) Appearance• Has the appearance been damaged by falling?
2) Test leads• Is the test lead cord damaged?
• Is the core wire exposed at any place on the test
leads?
If the built-in fuse is blown, current measurement is
impossible. Make sure that the test leads are not cut,referring to the section 5-1.

$&'&EXWWRQWARNING

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67$57
6723EXWWRQ

1. To avoid electric shock, do not remove the battery
compartment cover when input is applied to themeasurement terminal and clamp sensor or whenmeasurement is being performed.
2. Be sure to confirm that the function switch is set to “OFF”
before replacing the batteries.

%$&./,*+7
EXWWRQ

3RZHU
VZLWFK)XQFWLRQVZLWFK5DQJHVZLWFKCAUTION
Set the batteries with their polarities facing in the correct
directions.

fixing screws.
• About the batteries when shipped from the factory
The batteries incorporated when shipped from thefactory are monitor batteries, so their service life may be
shorter than that of brand-new batteries. A monitor
battery is a type of battery used to check the functions ofand performance of the product.
①④

②

③

6-4 Storage[7] AFTER-SALE SERVICE
7-1 Warranty and Provision
Sanwa offers comprehensive warranty services to its end-users andto its product resellers. Under Sanwa’s general warranty policy, each
instrument is warranted to be free from defects in workmanship ormaterial under normal use for the period of one (1) year from thedate of purchase.
This warranty policy is valid within the country of purchase only, andapplied only to the product purchased from Sanwa authorized agent
or distributor.
Sanwa reserves the right to inspect all warranty claims to determine
the extent to which the warranty policy shall apply. This warranty
shall not apply to fuses, disposables batteries, or any product orparts, which have been subject to one of the following causes:
1. A failure due to improper handling or use that deviatesfrom the instruction manual.
2. A failure due to inadequate repair or modification bypeople other than Sanwa service personnel.
3. A failure due to causes not attributable to this productsuch as fire, flood and other natural disaster.
4. Non-operation due to a discharged battery.
5. A failure or damage due to transportation, relocation or
dropping after the purchase.

CAUTION
1. The panel and the case are not resistant to volatilesolvent and must not be cleaned with thinner or alcohol.
2. The panel and the case are not resistant to heat. Do notplace the instrument near heat-generating devices (suchas a soldering iron).
3. Do not store the instrument, in a place where it may besubjected to vibration or from where it may fall.
4. For storing the instrument, avoid hot, cold or humid
places or places under direct sunlight or wherecondensation is anticipated.
Storage temperature/humidity range: -10 ~ 50°C, <80%
RH(without condensation)
5. When the instrument is not going to be used forextended time, be sure to remove the batteries.

7-2 Repair
Customers are asked to provide the following information whenrequesting services:
1. Customer name, address, and contact information
2. Description of problem
3. Description of product configuration
4. Model Number
5. Product Serial Number
6. Proof of Date-of-Purchase
7. Where you purchased the productPlease contact Sanwa authorized agent / distributor /service provider, listed in our website, in your country withabove information. An instrument sent to Sanwa / agent /distributor without those information will be returned to thecustomer.
Note:1) Prior to requesting repair, please check the following:• Capacity and installation polarity of the built-in
batteries.
• Continuity of the test leads.

− 14 −− 15 −

1 R e m o v e t h e t w o f i x i n g s c re w s f ro m t h e b a t t e r ycompartment cover.
2 Slide the battery compartment cover downward to

remove it.
3 Replace both of the two batteries in the batter y2) Repair during the warranty period:
The failed instrument will be repaired in accordancewith the conditions stipulated in “7-1 Warranty andProvision”.
3) Repair after the warranty period has expired:
In some cases, repair and transportation cost may
become higher than the price of the product. Pleasecontact Sanwa authorized agent / service provider inadvance. The minimum retention period of service
functional parts is 6 years after the discontinuation of
manufacture. This retention period is the repair warranty
period. Please note, however, if such functional parts
become unavailable for reasons of discontinuation of
manufacture, etc., the retention period may become
shorter accordingly.
4) Precautions when sending the product to be repaired
To e n s u r e t h e s a f e t y o f t h e p r o d u c t d u r i n gtransportation, place the product in a box that is larger
than the product 5 times or more in volume and fillcushion materials fully and then clearly mark “Repair
Product Enclosed” on the box surface. The cost ofsending and returning the product shall be borne by
the customer.
7-3 SANWA Website
http://www.sanwa-meter.co.jp
E-mail: exp_sales@sanwa-meter.co.jp

compartment with new ones.
− 4 −Notes:• This operation cannot be used with the MΩ measurement
function.
• When the function is switched, the REL measurement will becanceled.
4-5 BACKLIGHT Button (All Functions)
Press this button to turn on the backlight. The backlight willautomatically turn off after about 10 seconds.
4-6 DATA HOLD Button (DCV · ACV · DCA · ACA Functions)
When this button is pressed, “ ” will be illuminated on thedisplay and the measurement value displayed at that time will
be maintained. Pressing this button again will cancel the
DATA HOLD mode and restore the measurement mode.
Note: This operation cannot be used with the MΩmeasurement function.
4-7 Low Battery Indication (All Functions)
When the built-in batteries are exhausted and the battery
voltage drops below about 2.6 V,
will appear in the display.
If this icon is lit, replace the batteries with new ones (two at
the same time).

Function
DCV
ACVMax. rating input value
DC 600 V
AC 600 V

Measurement range
DC 600 V
AC 600 V

1) Applications
DCV:Voltage of the DC circuit is measured.
ACV: Sine wave AC voltage, such as lighting voltage, ismeasured.
2) Measurement procedure
1 Set the function switch to the “V” position and selecteither DCV or ACV with the AC/DC button.
2 Apply the red and black test pins to the circuit tomeasure.
• For measurement of DCV, apply the black test pin to
the negative potential side of the circuit to measure
and the red test pin to the positive potential side.
• For measurement of ACV, apply the red and black
test pins to the circuit to measure.
3 The reading of voltage is shown on the display.
4 After measurement, release the red and black test
pins from the object measured.
5 Be sure to set the function switch to the OFF position
after the measurement is complete.

[5] MEASUREMENT PROCEDURE
5-1 Start-Up Inspection
WARNING
1. Make sure that the low battery indication does notappear in the display.
2. Never use the instrument if the instrument or test leads
are damaged or broken.
3. Check continuity of test leads.

③
④

①
⑤

1. Never apply an input signal exceeding the maximum
rating input value.
2. Be sure to disconnect the test pins from the circuit whenchanging the function.
3. Always keep your fingers behind the finger guards on
the probe when making measurements.

− 8 −5-4 Clamp Current Measurement (CLAMP A)
WARNING
1. The clamp sensor of this instrument is exclusively for low
voltage. Perform the clamp current measurement on aline with 600 V or less.
2. Do not turn the function switch during measurement.
3. During measurement, do not hold the clamp sensor atany point beyond the barrier.
4. To prevent electric shock, be sure to store the test probe
and test lead in their designated storage compartments.

1. The measurable diameter of a conductor is 10 mm. Do
not force a cable with an outer diameter of more than 10
mm into the clamp sensor section. Also do not apply
external force to the clamp sensor section.
2. Make sure that the conductor to be measured is alignedwith the center of the arrows on the clamp sensor.
Otherwise, a measurement error will result.
3. Do not let this instrument come near a conductor inwhich large current flows or place it on a strong
magnetic field. Such an environment may cause ac u r re n t v a l u e t o b e d i s p l a y e d e v e n t h o u g h n omeasurement is made (an error may occur). Since theclamp sensor of this instrument is a U-shaped open-type
sensor, it is more susceptible to such an environment
compared than a closed-type sensor.
Measurement range
DC100.0A
AC100.0A

1) Applications
DCA: Measures the current consumption of devices
such as an automotive battery.
ACA: Measures the sine wave alternating current with40 ~ 400 Hz frequency of power supply facilities.
2) Measurement procedure
1 Raise the clamp sensor from the rear of the main unit.
2 Set the function switch to the CLAMP A position, andpress the SELECT button to select DCA or ACA.
• DCA: Use the REL function to set the display value to“000.0A” before measurement.
• ACA: No adjustment is necessary.

[8] SPECIFICATIONSTest lead length

8-1 General Specifications
Measurement
Display
Over ranging indication
Polarity selection

Low battery indication
Sampling rate
Response time of insulation
resistance measurement
Current measurement system
Max. clamp conductor diameterAC sensoring
Environmental condition
Accuracy-guaranteed
temperature/humidity range
Operating temperature/humidity range
Storage temperature/humidity range
Power supply
Power consumption

OutletWARNING− 11 −

ACV
measurement④

Accuracy is guaranteed in the case of sine wave.
The frequencies where accuracy is guaranteed in the
ACV measurement are 40 ~ 400 Hz.
Measurement of an inverter power supply circuit may
cause a malfunction.

5-2 Voltage Measurement

Max. input rating value
DC100.0A
AC100.0A

DCV
measurement②

Note: If there is no display, the batteries may be exhausted.

Function
DCA
ACA− 13 −

Battery④④

CAUTION⑧

WARNING

6-3 Battery Replacement'$7$+2/'
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Note: AC voltage and AC current are regulated by rms,
values of sinusoidal wave.

4 Place the battery compartment cover and tighten the[6] MAINTENANCE

6-2 Calibration
The manufacturer may conduct calibration and inspection.
For more information, please contact your dealer.
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− 7 −

7

WARNING

Rated
measurement
voltage range
50 V
125 V
250 V

DCV · ACV

− 6 −5-3 Insulation Resistance Measurement (MΩ)

Function

Inputterminals

Function

2-2 Features• Compact, lightweight, portable design that easily fits into a
breast pocket.
• Insulation resistant measurement settings can be switchedbetween 3 rated measurement voltage ranges (250 V/125
V/50 V) with the full-scale value of 40.00 MΩ.
• Provided with a current clamp sensor that can measure up
to 100 A DC/AC.
• The clamp sensor has a thin U-shaped sensor design thatis 7 mm thick. Also because the inclination angle of thesensor is variable between 0° and 180°, the display sectionof the main unit can be adjusted to an easy-to-view angle.
• Provided with an AC/DC voltage measurement function thatcan be used for checking live line conditions on site.
• The LCD panel incorporates an electroluminescentbacklight for easier operation in dark or low-light conditions.
• The storable sections of the test leads and test probes use
an elastomeric material that is easy to wind and store.
• Provided with a clip adapter useful for measurement.

− 3 −4-1 Power Switch/Function Switch/Range Switch (All Functions):
Turn this switch to turn the power ON and OFF and to selectthe measurement function, as well as the rated measurement
voltage range of the MΩ function.

Clip adapter
CL-DG3a1-3 Overload Protections− 2 −Test Leads
Clamp
sensor(when stored)

3. When insulation resistance is being measured, the builtin batteries will be used up rapidly due to the generationof high voltage. Try to minimize the measurement time.
4. The measurement value may flicker while insulation
resistance is being measured.
5. When the electroluminescent backlight is turned on,
built-in batteries will be depleted more rapidly. Use it
only when it is necessary.
6. Correct measurement may not be possible in areas
exposed to strong magnetic fields generated byelectrical equipment such as a transformer or large
current path, electromagnetic waves generated bywireless equipment, or areas where electrostatic
charges are generated.
7. This instrument may malfunction or may not be able totake correct measurements with special waveforms suchas those produced by an inverter circuit.

Align one line of the conductor to be measured withthe center of the arrows on the clamp sensor.
• DCA: Point the object to be measured in the same
direction as the current direction marking. If it
is pointed in the opposite direction, “–” will be
displayed.
• ACA: The current direction of the object to bemeasured is irrelevant.
4 Read the measurement value in the display.
5 After measurement, remove the conductor from theclamp sensor.
6 Be sure to set the function switch to the OFF position
after completing measurement.
3

Double integral method
Max. 3999 countMost significant digit blinks
Automatic selection (–display only)
Displayed when built-in
batteries are exhausted (to2.6 V or less) with
lit orblinking in display
Approx. 2 times/sec

Accessories

Approx. 60 cm for both red
and black
Black alligator clip
(CL-DG3a), instruction
manual* Per measurement time: 5 sec. (measurement interval — 25sec.). The number varies depending on the batteries used.

8-2 Measurement Range and Accuracy
Accuracy assurance range: 23 ± 5°C & less than 80% R.H.
No Condensation
Function
DCV
DC Voltage

ACV
AC Voltage

Number of insulation
resistance measurementsthat can be performed withbrand-new batteries*

Approx. 5000 or more,
successively, in 250 V
range

Dimensions & weight130 (L) x 75 (W) 19.9 (D) mm(excluding protrusions),
approx. 160 g (including
batteries)

Range
600 V

600 V

50 V

Approx. 3 sec. or lessMΩ
40.00 MΩCT clamp
10 mm
Average sensoring
Operating altitude <2000 m,
indoor use, pollution degree II
23 ± 5°C, <80% RH (without
condensation)
5 ~ 40°C, <80% RH (without
condensation)–10 ~ 50°C, <80% RH(without condensation)
Two LR03 alkaline batteries
Maximum power consumption— Approx. 25 mW (insulation
resistance 250 V range, 10MΩ load measurement)− 16 −

Accuracy

Input impedance±(1.1%rdg+3dgt)

Approx. 10 MΩ±(1.6%rdg+7dgt)±(3.0%rdg+6dgt)

125 V±(3.0%rdg+3dgt)
250 V

DCA
DirectCurrent

100.0 A±(2.0%rdg+5dgt)

ACA
Alternating 100.0 A
Current±(2.0%rdg+5dgt)

Approx. 10 MΩ

Remarks• Accuracyguaranteed
range: 40 ~400 Hz• Accuracy
in the caseof sin wave

See “Specifications for
Insulation Resistance
Measurement” and“Specifications for Insulation
Resistance Measurement”.
• Accuracy was measured
after canceling display value
by the REL function.
• Accuracy-guaranteed
range: 40 ~ 400 Hz• Accuracy in the case of sin
wave• Specifications for Insulation Resistance Measurement<No-load measurement voltage>
Rated measurement
No-load voltage
voltage1 ~ 1.2 times that of rated measurement
50 V/125 V/250 V
voltage<Rated measurement voltage/short-circuit current>
Rated
Rated
Shortmeasurement measurement circuit
voltagecurrent
current
50V
125V
250V

Approx.
5 μA
Approx.
12.5 μA
Approx.
25 μA

Approx.
5 μA
Approx.
12.5 μA
Approx.
25 μA

40 MΩ

Measurement
extent00.00 MΩ ~39.99 MΩ

Note: Correct measurement may not be possible in areas
exposed to strong magnetic fields generated byelectrical equipment such as a transformer or large
current path, electromagnetic waves generated bywireless equipment, or areas where electrostatic
charges are generated.
Accuracy calculation
Ex.) Measurement of AC voltage (ACV)
Display value:
0100 V
Range accuracy: ± (1.6%rdg+7dgt)
Error:± (0100 V x 1.6%+7dgt) = ±8 V
True value:
0100 V ± 8 V (in a range of 0092 ~0108 V)
Note: 7 dgt corresponds to 7 V.
Specifications and external appearance of the productdescribed above may be revised for modified without
prior notice.

Measurement
resolution
0.01 MΩ− 17 −− 18 −− 19 −− 20 −− MEMO −− MEMO −− MEMO −− MEMO −− 21 −− 22 −− 23 −− 24 −&ODPS6HQVRU
CenterpositionmarkingBarrier①⑤③Current direction
marking④

Conductor to
be measured(electrical wire)

Current
direction②

Barrier

When the position of this instrument is changed
during DCA measurement, the display may fluctuate
due to geomagnetism.
Because the AC sensoring system of this instrument
is an average value system, an error in the measured
value will occur with waveforms other than sine
waves.
Accuracy is guaranteed in ACA measurement
between 40 ~ 400 Hz.
Measurement of an inverter power supply circuit may
cause a malfunction.
− 12 −

Approx.
10 MΩ ormore

rdg: reading dgt: digits• Specifications for Insulation Resistance Measurement<Measurement range>
Measurement
range

Resistancevalue at which
ratedmeasurement
voltage canbe maintained