M53

DIGITAL INSULATION METER
WITH VOLTAGE & SPEED RANGEINSTRUCTION MANUAL

[1] Safety Precautions --- Be sure to read before use. --Be sure to read carefully the information under “
WARNING” and“ CAUTION” in this manual in order to prevent human injuries, electric
shock and damage to the instrument as well as other equipment.

1-1 Warning Markings and Other Symbols
The symbols and their meanings used with the instrument and in thismanual are as described below.
WARNINGCAUTION

The information under this marking must be
observed strictly to prevent human injuries,
including burns and electric shock.
The handling information under this marking
should be observed carefully to prevent damage
to the instrument and associated equipment.

Other symbols used with the instrument and in this manual
Indicates a risk of shock due to a high voltage generated
or applied at a measuring terminal.
E
Insulation resistance measurement terminal (Earth=GND)
L
Insulation resistance measurement terminal (Line)ACV
AC voltage
DCV
DC voltage
MΩ
Insulation resistanceV. SPEED
Voltage and speed measurement terminal
Voltage polarity DCV:+positive terminal, ACV:~(No polarity)
Voltage polarity DCV:-negative terminal, ACV:~(No polarity)
SPEED m/min Speed measurement range (DCV 0~20 V range)
INSUL.
TEST VOLT
Insulation test voltage ON indication
ON
POWER
Measuring power switch−1−

1-2 Warning Messages for Safety
WARNING
1. Check the measurement type (insulation resistance, DC or AC
voltage) before measurement and select the appropriate
function for it.
2. Do not apply a voltage or signal exceeding the specified
maximum allowable input. (For the maximum allowable input
voltage value, see section 1-3 on the next page.)
3. Do not open the case or battery cover unless replacing thebatteries as described in this manual.
4. Always use the test leads specified in the manual.
5. If the insulation coating of a test lead is damaged or its
conductor wire is exposed, do not attempt to repair it.
Instead, replace with a new test lead.
6. Do not switch the measuring function during measurement.
7. Do not use the instrument when it is moistened, when yourhand is wet or when the ambient humidity is high (85 %RH or
more).
8. Do not touch the metallic parts of the test leads during
measurement.
9. Do not use the instrument if it is defective and incapable ofmaking the specified measurements.
10. Do not use the instrument using high-power or higher voltage
circuitry than the maximum allowable input.
11. Be sure to conduct annual inspections.

−2−

1-3 Maximum Allowance Input Value
Function

Input terminal

Insulation resistance(500 V, 15 V)
ACV, DCVE〜

MΩ
V. SPEEDMax allowance input value
Voltage or Current
Input prohibitedL〜

AC 750 V, DC 750 V[2] Overview and Features
2-1 Overview
This device is a digital insulation resistance tester, with DCV & ACV
measurement functions.
In addition to that, it also has optional speed measurement function(Sanwa speed meter SE-9000 is necessary to use this function), thatenables to read output voltage value directly as a speed value.
2-2 Features
1. Two test voltage ranges DC 500 V and DC 15 V
2. Auto range
3. Auto power off after one minute from power-on.
4. Low battery indication function.
5. With optional tachometer SE-9000, remote speed measurement
can be made.

−3−

[3] Appearance and Appellation

(1)

(2)

(5)

(3)

(4)

(

)

(

)

(6)
(7)
(8)

(1) Measurement terminal (Insulation
resistance, ACV, DCV)
(2) LCD(3) Function switch(4) Power switch(5) Insulation resistance measurement
voltage input indication lamp (red LED)
(6) Red test lead (L, side)(7) Black test lead (E, side)(8) Clip lead for connecting pin−4−[4] Measuring Methods
4-1 Preparations
WARNINGFor safe use of the instrument, check its appcarance and associatedaccessories carefully before use.
1. Check for damage due to dropping, etc.
2. There is a risk of electric shock if the insulation coating of a test
lead or its conductor wire is exposed. Check the test leads
carefully before use.
NOTE: Operation of the POWER Switch and Auto Power OFF
The POWER switch of the instrument toggles, or alternates operation,
so that each successive press switches the selected measuring function
from ON to OFF, and vice versa. The auto power OFF feature provided
turns power OFF automatically in about 1 minute, as a safeguard forwhen you forget to set the POWER switch to OFF after use. Still, we
recommend pressing the POWER swith to OFF after measurement tosave the power of the built-in batteries.
4-2 Checking the Built-in Batteries
1. Do not connect any leads to the measuring terminals.
2. Set the function switch to 500 V or 15 V.
3. Press the POWER switch.
4. The built-in batteries are normal if the INSUL. TEST VOLT ON
indicator (red LED) lights up and the LCD looks as shown in Fig. 1.

Fig 1
−5−

5. If the INSUL. TEST VOLT ON indicator does not light and the
LCD shows nothing even when the POWER switch is pressed toON, the batteries may be exhausted completely, or no battery has
been loaded. In this case, remove the battery cover on the rearcase and insert new batteries as described in section 4-3,
“Replacing the Built-in Batteries” on the next page.
6. If the INSUL. TEST VOLT ON indicator does not light and the LCD
shows nothing, although unexhausted batteries are loaded, it ispossible that the battery terminal contacts have failed. In this case,remove the battery cover on the rear case and check the contacts
between the batteries and terminals.
7. If the INSUL. TEST VOLT ON indicator lights up but the LCD showsthe “B” marking as shown in Fig. 2 when the POWER switch ispressed to ON, the built-in batteries are nearly exhausted. In thiscase, replace them with new batteries.

Fig 2
4-3 Replacing the Built-in Batteries
1. Set the function switch to OFF on the center position.
WARNING
Make sure that the function switch is set to OFF before proceeding
to the battery replacement operation.
2. Refer to Fig. 3 below for the battery replacement.
3. Remove the lock screw on the battery cover on the rear case, thenremove the battery cover by sliding it down while pushing thesquare projection on the top center (Fig. 3[A]) with your finger, andinsert batteries in correct polarity positions as shown by Fig. 3[B].
4. After checking that the batteries have been inserted correctly,
place the battery cover in the original position on the rear case andfasten with the lock screw.

−6−1.5 V battery

Battery cover

Press and
slide
φ3 mm
screw

A
◯

Fig. 3B◯

CAUTION
1. Always use the specified batteries (LR6 batteries).
2. To prevent performance degradation, replace all six batteries
with six brand-new ones when the time comes to replacebatteries.

4-4 Measurement of insulation resistance (MΩ)
WARNING
1. When the power is ON with the insulation resistance measuringfunction selected (when the INSUL. TEST VOLT ON indicator
is lit), a high voltage for insulation resistance measurement isapplied across the E-L terminals. To avoid the risk of electric
shock, do not touch the metallic parts of the test leads connectedto the measuring terminals.
2. Make sure that the object to be measured is not subjected tovoltage before proceeding to measurement.
3. Certain measurement objects (capacitive objects, for example)
may retain the voltage applied from this instrument for sometime after the completion of the measurement.

−7−

1. Set the function switch according to the measurement object, to500 V or 15 V.
2. Connect the black plug of the black test lead to the E terminal on
the left and the amber plug of the red test lead to the L terminal on
the right as shown in Fig. 4.
Black
Red
Fig. 4

3. Connect the black clip to a measuring point on the measurement
object and the tip of the red test rod to the other point, and press the
POWER switch. The INSUL. TEST VOLT ON switch will light up
and the resistance measurement value will be shown on the LCD.
4. When the measurement object has resistance of more than
200 MΩ at 500 V or 20 MΩ at 15 V, the LCD shows the same overinput display as that displayed when the measuring terminals areopen, as shown in Fig. 1 under section [4]4-2, “Checking the Builtin Batteries” on page 5.
5. After measurement, press the POWER switch again to OFF or set
the function switch to OFF.

NOTE: Distiaction Between E and L Terminals
When one of the measuring points is grounded, connect it to the E
terminal of the instrument.
This is specified in consideration of safe use, because the resistancemeasurement value reading in the insulation testing can be reducedin this way. In other measurement operations, consideration of thepolarity of measurement points is not necessary.

−8−

NOTE: In Case the “B ” Marking is Displayed During Measurement
When the resistance measurement value in an insulation test is
extremely small, the LCD sometimes shows the “B” marking which isusually used as the battery alarm indicator. In the present case, the“B” marking is displayed because an extremely small resistancemeasurement value means consurption of large battery current andthe drop in capacity due to exhaustion of the batteries causes theinternal operating voltage to fall below the specified level.
4-5 Measuring the AC Voltage (ACV)WARNING
1. The maximum allowable input voltage of the ACV range is
750 V. Never apply a higher voltage than this.
2. Voltages higher than 25 Vrms AC are hazardous to the humanbody. Be very careful during measurement.
3. Never attempt to change the function switch position during
measurement.
4. Never touch the device with a wet hand.
1. Set the function switch to ACV.
2. Connect the amber plug of the red test lead to the terminal on
the right and the black plug of the black test lead to the terminalon the left as shown in Fig. 5.

Black
Red
Fig. 5−9−

3. Press the POWER switch to ON, connect the black clip to ameasuring point on the measurement object, and apply the tip of
the red test rod to another measuring point. The LCD will show themeasurement voltage value.
4. After measurement, press the POWER switch again to OFF or set
the function switch to OFF.
4-6 Measuring the DC Voltage (DCV)WARNING
1. The maximum allowable input voltage of the DCV range is
750 V. Never apply a higher voltage than this.
2. DC Voltages higher than 60 V are hazardous to the human body.
Be very careful during measurement.
3. Never attempt to change the function switch position during
measurement.
4. Never touch the device with a wet hand.
1. Set the function switch to appropriate range, but if the voltage to bemeasured is uncertain, set it to DCV 0-750 V range.
2. Same as the ACV measurement, connect both black & red plugs tomeasurement terminals.
3. Press the POWER switch to ON, connect the black clip to the earth
line (lower voltage side) and red point on the measurement object(higher voltage side), the LCD will show the measurement voltage
value.
4. If the measured value is less than 20 V, then turn off the device, andmake measurement again by setting the function switch to DCV
0-20 V range.
5. After measurement, press the POWER switch again to OFF or set
the function switch to OFF.

− 10 −

4-7 Speed(m/min) measurement
1. The measurement method is the same as DCV measurement, but
set the function switch to DCV 0-20 V.
2. As shown in Figure 6, connect optional cable of SE-9000 (speed
meter), positive red plug to the right side of L terminal, and negative
black plug to E terminal.
3. Press power switch, and then analog output value from speed meter
will be shown on the display as mV value. Read that value directly
as m/min.

To SE-9000 analog output
Fig. 6[5] Maintenance & Management
WARNING
This section contains important information for maintenance. The
maintenance of the instrument should be performed by managing
personnel who understand the instrument and this manual in detail,and who are well-acquainted with handling the instrument.

5-1 Maintenance & Inspections
WARNINGBe sure to maintain and inspect to ensure safe, long-lasting
optimum-performance use of the instrument.

− 11 −

1. Check that the external finish of the instrument is not damaged
due to dropping etc.
2. Check the test leads to ensure that
· a plug is not loose when it is inserted into a terminal;· the test lead coating is not damaged;· the conductor wires are not exposed from any part of the test leads.
3. Check that the function switch is not subject to strong pressure fromabove. (This could lead to a contact failure of the switch.)
If the instrument cannot comply with any of the above checks, do notuse it as it is. Service the defective part or replace it with a new part.
5-2 Calibration
WARNINGTo maintain safety and accuracy, conduct inspections andcalibration at least every year. For inspection and calibration,please consult a dealer in your area or the local sales
representative for the instrument.
5-3 Storage
WARNING
1. The panel and rear case are not resistant to volatile solventsor heat. Do not attempt to clean them with lacquer thinner or
alcohol, or place the instrument near a source of heat. To
clean the instrument, wipe lightly with a soft, dry cloth.
2. Do not store the instrument in a place subject to vibration, or where
the instrument may drop.
3. Do not store the instrument under direct sunlight, under
extremely high or low temperatures, or in a place where toxic
gas is generated.
4. When the instrument is not used, be sure to set the function
switch to OFF.
5. When the instrument is not to be used for a long period of time,
be sure to remove the built-in batteries before storing it.

− 12 −

[6] After-Sales Service
6-1 Warranty and Provision
Sanwa offers comprehensive warranty services to its end-users
and to its product resellers. Under Sanwa's general warranty
policy, each instrument is warranted to be free from defects inworkmanship or material under normal use for the period of one(1) year from the date of purchase.
This warranty policy is valid within the country of purchase only,
and applied 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 deviates from the
instruction manual.
2. A failure due to inadequate repair or modification by people
other than Sanwa service personnel.
3. A failure due to causes not attributable to this product such 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.
6-2 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 product− 13 −

Please contact Sanwa authorized agent / distributor / service
provider, listed in our website, in your country with above
information. An instrument sent to Sanwa / agent / distributor
without those information will be returned to the customer.
Note:
1. Prior to requesting repair, please check the following:
Capacity of the built-in battery, polarity of installation anddiscontinuity of the test leads.
2. Repair during the warranty period:
The failed meter will be repaired in accordance with theconditions stipulated in 6-1 Warranty and Provision.
3. Repair after the warranty period has expired:
In some cases, repair and transportation cost may become
higher than the price of the product. Please contact Sanwa
authorized agent / service provider in advance.
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 ensure the safety of the product during transportation,
place the product in a box that is larger than the product 5
times or more in volume and fill cushion materials fully andthen clearly mark “Repair Product Enclosed” on the box
surface. The cost of sending and returning the product shallbe borne by the customer.
6-3 SANWA web site
http://www.sanwa-meter.co.jp
E-mail: exp_sales@sanwa-meter.co.jp− 14 −

[7] Specifications
7-1 Insulation Resistance Measuring Block
1. Rated voltage DC 500 V, DC 15 V, 2 ranges
2. Measuring voltage/current characteristics DC 500 V range
When measuring terminals are open 600 V (+20 % max.)
When measuring terminals are shorted Approx. 1.6 mA max.
DC 15 V range : 15 V±10 % at 1 MΩ
3. Measurement range
DC 500 V range : 0 to 2 MΩ/1 M to 20 MΩ/10 M to 200 MΩ, 3 auto
range switching
DC 15 V range : 0 to 2 MΩ/1 M to 20 MΩ, 2 auto range switching
4. Measuring accuracy : Within ±(2 % reading + 2 digit)
5. Applied voltage indication : Red LED with 5 mm dia.
7-2 AC Voltage Measuring Block
1. Measuring range
0 to 750 V max.
0 to 200 V/10 to 750 V, 2 auto range switching
2. Measuring accuracy :Within ± (1 % of reading + 0.5 % of range + 1 digit)
Frequency : 50 to 400 Hz
3. Input resistance 10 MΩ
7-3 DC Voltage Measuring Block
1. Measuring range : 0 to 20 V, 0 to 750 V max, 2 range.
0 to 20 V
0 to 2000 mV/1 V to 20 V, 2 auto range switching
0 to 750 V 0 to 200 V/10 V to 750 V, 2 auto range switching*Speed measurement (m/min) : 0 to 2000 mV range
1 m/min = 1 mV (Refer to the instruction manual for SE-9000)
2. Measuring accuracy :Within ± (0.5 % of reading + 0.5 % of range + 1 digit)
3. Input resistance 10 MΩ− 15 −

7-4 Common specifications
1. A/D converter
Operating system: Double integration
Sampling rate: Approx. 2.5 samplings/sec.
2. Display
LCD, max. 1999
3. Over-input indication Only the highest digit shows “1”.
4. Polarity indication“—” when measuring DCV
5. Measuring terminals Insulation resistance MΩ: E, L.
Voltage: ACV & DCV (V. SPEED) : ,6. Operating temperature/humidity
0 to 40 ˚C, 85 %RH (without condensation)
7. Accuracy guaranteed temperature/humidity
15 to 30 ˚C, 80 %RH (without condensation)
8. Built-in batteries
LR06(IEC)(x6)
9. Built-in battery life (time until battery voltage drops to 7 V)
When power is switched between ON and
OFF every minute in succession
Insulation resistance measurement (measuringterminals open): Approx. 50 hours
AC voltage measurement: Approx. 300 hours
10. Battery alarm
LCD shows “B” mark when battery voltage
drops below 7 V
11. Auto power OFF time
Approx. 1 minute after power ON
12. Dimensions & mass
175(H) x 115 (W )x 55(D) mm, approx. 600 g
7-5 Accessories
1. Red test lead with amber plug (L, terminal) x 1
2. Black test lead with black plug (B, terminal) x 1
3. Alligator clip adapter x 1
Set of the avobe 3 test leads: TL-M54
4. Instruction manual x 1
5. Carrying case C-M53 (with cord case) x 1
The specifications in this manual may be subject to change for
performance improvement without notice.

− 16 −

MEMO

MEMO

本社=東京都千代田区外神田 2−4−4･電波ビル
郵便番号=101-0021･電話=東京（03）3253−4871（代）
大阪営業所=大 阪市浪速区恵美須西2 −7 −2
郵便番号=556-0003･ 電話 = 大阪（06）6631−7361（代）
Dempa Bldg., 4-4 Sotokanda 2-Chome, Chiyoda-Ku, Tokyo, Japan

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