Megger MIT430/2-KIT, MIT420/2-KIT, MIT420/2, MIT400/2, MIT430/2 User manual

M

MIT400 Series
Insulation and continuity testers

USER GUIDE

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USER GUIDE CONTENTS

1. Introduction 3

Safety Warnings 4

2.

3. Symbols used on the instrument 5

4. General Description 6

Unpacking the carton 6
Carton contents (all instruments) 6

5. Preparations for use (all instruments) 7

Batteries 7
Preliminary test lead check 7

6. General operating instructions 8

General functions 8
LCD Display 9
Backlight operation 10

7. Test lead connections 11

Standard test leads 11
SP5 Switched probe (not MIT400, MIT480 and MIT40X) 11

8. AC/DC voltage and frequency measurements 12

9. Insulation resistance testing - general 13

Standard insulation resistance testing 13
Insulation resistance testing – timed modes ‘t’, PI and DAR 14

10. MIT40X testing 17

11. Continuity testing [] and buzzer [

12. Resistance measurements (k Range) 19

13. Capacitance measurements 20

Capacitance measurement procedure 20
Distance measurement by capacitance 20

14. Setup options 21

15. Saving , recalling and downloading test results. 23

Saving test results 23
Test results recall 23
PI and DAR recall. 24

16. Deleting test results 26

Procedure for deleting a single test result (refer to Figure 16) 26
Procedure for deleting all test results (refer to Figure 19) 27
Preparing your MIT430 or MIT485 for “Bluetooth” Communications 29
Preparing your MIT430 or MIT485 to your PC 29
Standard download operation 32

17. Battery and fuse replacement 32

Battery condition and replacement 32
Blown fuse indicator 33

18. Preventive maintenance 33

19. Specification 34

20. Basic and service errors 36

Basic error 36
Service error: 36

21. Accessories 37

22. Repair and Warranty 39

] 18

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1. Introduction

Thank you for purchasing the Megger insulation test instrument.

For your own safety and to get the maximum benefit from your instrument, please ensure
that you read and understand the following safety warnings and instructions before
attempting to use the instruments.

This user guide describes the operation and functions of the MIT400 series of insulation and
continuity test instruments:

These instruments are designed and manufactured by:

Megger Ltd
Archcliffe Road
Dover Kent
CT17 9EN
England

Megger Limited reserves the right to change the specification of these instruments at any
time without prior notice.

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2. Safety Warnings

mus t

N OTE

MIT400 series insulation testers

Safety Warnings and Precautions must be read and understood before the instrument is
used. They must

1

The circuit under test must be switched off, de-energised, securely isolated and

proved dead before test connections are made when carrying out insulation and
continuity tests.

Circuit connections and exposed-conductive-parts and other metalwork of an

2

installation or equipment under test must not be touched during testing.

The live circuit warning and automatic discharge are additional safety features,

3

which may fail, and therefore safe working practices must be observed.

The voltage function will only work if the instrument is functional and switched on.

4

After insulation tests, capacitive circuits must be allowed to discharge before

5

disconnecting test leads.

The instrument should not be used if any part of it is damaged.

6

All test leads, probes and crocodile clips must be in good order, clean and with no

7

broken or cracked insulation.

Ensure that hands remain behind guards of probes/clips when testing.

8

National Safety Authorities may recommend the use of fused test leads when

9

measuring voltage on high-energy systems.

Replacement fuses must be of the correct type and rating. Failure to fit the correctly

10

rated fuse may result in a safety hazard and may cause damage to the instrument in
the event of an overload.

The battery cover m

11

be observed during use.

be in place whilst conducting tests.

THE INSTRUMENT MUST ONLY BE USED BY SUITABLY TRAINED AND COMPETENT

PERSONS.

Users of this equipment and/or their employers are reminded that National Health and Safety
Legislation requires them to carry out valid risk assessments of all electrical work so as to
identify potential sources of electrical danger and risk of electrical injury such as inadvertent
short circuits. Where the assessments show that the risk is significant then the use of fused
test leads may be appropriate.

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3. Symbols used on the instrument

F Caution: risk of electric shock

G Caution: refer to accompanying notes

Displayed on the LCD during an insulation test, warns that a hazardous
voltage may exist at the test lead probes also observe voltage discharges
to a safe level.

On battery cover see section 2.0 notes 10 and 11.

At terminals do not exceed rated input voltage.

Equipment protected throughout by Double Insulation (Class II)

Equipment complies with relevant EU Directives

Equipment complies with ‘C tick’ requirements

Do not dispose of in the normal waste stream

G>600 V Maximum input voltage 600 V rms

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4. General Description

4.1 Case contents

There are important documents that you should read and keep for future reference.

Please complete the pre-paid warranty card and return it to Megger Limited as soon as
possible to help us reduce any delays in supporting you should the need arise.

4.2 Case contents (all instruments)

1 x MIT400 series instrument

1 x Hard carry case
1 x Red/black test lead set with clips
5 x AA (LR6) batteries fitted
1 x Warranty card
1 x Calibration certificate
1 x Owners CD manual
1 x SP5 remote switched probe (Not MIT400 &MIT480)
1 x Download Manager software CD (MIT430 and MIT485 only)

MIT400 storage with holster MIT400 storage with no holster

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5. Preparations for use (all instruments)

5.1 Batteries

The Megger MIT400 series instruments are supplied with batteries fitted. When batteries
become exhausted, refer to section17 for battery replacement.

Warning: Do not switch the instrument on or connect test leads with the battery cover
removed.

5.2 Preliminary test lead check

Functio nal verification

1.

Before each use of the instrument visually inspect the test leads, prods and crocodile
clips to confirm that their condition is good, with no damaged or broken insulation.

Check continuity of the test leads by firmly shorting the leads together and read the

2.

test lead resistance measurement directly from the d isplay, which should be less than

1.0 .

Supply voltage

With the exception of voltage measurement range, this instrument is designed for
use on isolated (dead) circuits. Prior to any testing and using an approved method,
ensure the circuit to be tested has been fully disconnected and is securely isolated
from the supply prior to using the instrument.

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6. General operating instructions

Safety note:

If greater than 25 V appears on the circuit under test the instrument will default to a
voltage measurement and display the supply voltage.

On supply voltages over 50 V the instrument will be prevented from performing an insulation
test, protecting your instrument from damage.

Note: This limit is increased on MIT480, MIT481 and MIT485 to 75 V, but a warning
buzzer will indicate voltages above 50 V.

Use extreme care when using or measuring voltages above 30 V, particularly in high energy
systems.
Fused test leads are available as an optional accessory for local situations where increased
protection is required.

Hazardous voltages can exist on the insulation test range all the time the [TEST] button
is locked down.

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6.1 General functions

Black Test lead
connection

LCD screen

Test button and
lead null

Insulation lock
button

Insulation test
ranges

OFF positon

Resistance ranges

Capacitance (μF)

Figure 3 Main features (MIT430 shown)

Red test lead or
switched probe

Function
buttons

Battery/internal
fuse access
panel at rear

Voltage range

Result recall and
transfer

Insulation, PI test, DAR test
or timed test button

Store/last button

TRMS/DC button

Up/down buttons

μA/s/V button

Next button

Buzzer on/off

Backlight button

Test button

Figure 4 Function buttons (MIT430 shown)

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6.2 LCD Display

Auxiliary digital display

Multifunction
analogue display

Continuity indicator

Lock indicator

Warning – refer to
user manual

Fuse blown indicator

Out of range
indicator
Lead null indicator

Figure 1 LCD display

6.3 Voltage warning

If the voltage is greater than 25 V the meter automatically displays the voltage.

For MIT400, MIT405, MIT410, MIT420, MIT430 and MIT40X instruments, if a voltage greater
than 50V exists, testing will be a utomatically inhibited and voltage measurement will be
displayed.

For MIT480, MIT482, MIT485 instruments, if a voltage greater than 75 V exists, testing will be
automatically inhibited and a voltage measurement will be displayed. Voltages higher than 50
V will be indicated by a warning buzzer.

In continuity mode, if a voltage greater than 25 V exists, testing will be automatically inhibited
and voltage measurement will be displayed.

Units of parameters on
auxiliary display

Battery condition
indicator

Audible alarm indicator

TRMS indicator

Units of parameters on
main display

6.4 Backlight operation

All instrument displays are backlit. The backlight function can be selected at any time while

the instrument is switched on by pressing the BACKLIGHT [

The backlight function will switch off automatically after 20 seconds.

] button. Refer to figure 4.

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7. Test lead connections

Test lead s co n ne c tions are as indicat e d in f igur e 2 which shows the te st le ad sockets at
the top of the instrument, as well as the switched probe socket and test lead.

Black test lead
connection

Figure 2 Test lead connections

Red test lead
connection

SP5 connection

7.1 Standard test leads

The Red/Black test lead set should be connected to the appropriate sockets on the top of the
instrument marked + and –, respectively. (see figure 2 )

Test probes and crocodile clips are supplied for connection to the circuit under test.

Fused test leads are available as an optional accessory.

7.2 SP5 Switched probe (not MIT400, MIT405, MIT480 and MIT40X)

The SP5 switch probe allows the user to start a test by pressing the [TEST] button on the
probe, instead of on the instrument. This allows for complete hands-free testing and
increases user safety.

1.

Connect the SP5 probe to the instrument using the special 3-pole +ve socket (in place
of the RED test lead).

Select a suitable insulation resistance range.

2.

Press and hold down the SP5 probe button. The instrument will start an insulation

3.

resista nce test.

To end the test, release the probe test button.

4.

The SP5 remote switch probe replaces the standard red test lead. The test button on the
probe duplicates the test button operation on the instrument when insulation testing.

To operate the switch probe, connect the probe to the circuit to be tested and press and
hold down the button on the probe. The insulation test will commence. Releasing the button
will terminate the test.

The test lead resistance can be nulled for continuity testing. Refer to section 11.2

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8. AC/DC voltage and frequency measurements

Note: Measured voltage must not exceed 600 V phase to earth or Phase to Phase

Frequency measurement is not available on MIT400, MIT405 and MIT480 models.

Procedure for measurement of volta ge and frequency

(Refer to Figure 5)

DC indicated

Screen B:

Analogue a.c. voltage

Screen A (a.c.)

displayed

Step 4:

Measured frequency

Voltage and frequency
display d.c. and voltage

display in d.c. mode

Step 5:

Result store button

Step 3:

TRMS/DC

TRMS indication

Measured a.c. voltage
(V or mV)

Test button

Step 2:

Connect test lead to
circuit under test

Step 1:

Selector switch

Note on TRMS measurement:

IN TRMS mode the MIT400 will measure both AC and DC components of the supply voltage (AC+DC).
In DC mode only the DC component is measured.

Rotate selector switch to the ‘V’ position.

1.

Connect test leads to the circuit under test.

2.

3.

‘TRMS’ is the default mode on power-up. Press the [TRMS] button to select DC or return to
TRMS if required.

The measured voltage will be displayed on the main digital scale in units of V or mV, as

4.

appropriate In TRMS mode, the measured frequency (Hz) will be simultaneously displayed on
the MIT410, MIT420, MIT430, MIT 481, and MIT 40X instruments (as shown on Screen A). See
Figure 5 Screen B

For MIT420, 430, 481 and 485, the measured result may be stored if required by pressing the

5.

‘STORE’ button. Refer to section 14 for further information.

Figure 5 Voltage and frequency measurement

for dc mode display.

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9. Insulation resistance testing - general

Safety note:
Insulation resistance testing is performed at high DC voltages and is hazardous if
touched. Always observe the safety precautions when performing an insulation
resistance test, and ensure all necessary health and safety precautions are observed.

Automatic Discharge: Capacitive circuits are automatically discharged when the test button

is released following an insulation test.

The circuit under test must be completely de-energized and securely isolated before test
connections are made.

9.1

Standard insulation resistance testing

(Refer to Figure 6)

Note: For MIT40X refer to section 10.

1.

Connect the test probes to the isolated circuit under test.

Turn the instrument ‘ON‘ by rotating the selector switch to the desired test voltage (50

2.

V, 100 V 250 V, 500 V or 1 kV).
Press and hold the [TEST] button to start the test.

3.

The insulation resistance value, in both analogue and digital form is displayed together

4.

with the actual

6).

The insulation test can be locked on, by pressing the lock button [ ] whilst holding

5.

down the [TEST] button. To disable lock press the [TEST] button or lock [

By pressing the [uA/V/s] button, the leakage current can be displayed (see Screen B).

6.

Not available on the MIT400 or MIT480.

Release the [TEST] button before removing the test leads (to enable the instrument to

7.

discharge the circuit under test). If the display shows VOLTS, wait until it reaches zero.
On completion of testing, switch to the ‘OFF’ position. Alternatively auto shut-off

8.

operates after 15 minutes of inactivity.

test voltage displayed on the secondary display (see Screen A of figure

] button.

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Screen B

Step 1:

Connect the test leads

Symbol displayed
if audible limits

are enabled

M changes to G
where required

Step 4:

Test result and actual
test voltage

Step 3:

Press TEST and hold

Step 7:

Release TEST button

Step 2:

Select test voltage

Step 8:

Switch off

Figure 6 Standard mode insulation test

9.2 Insulation resistance testing – timed modes ‘t’, PI and DAR

Screen A

Step 6:

Amps, volts and seconds
selection button

Alarm on/off

Step 5:

Press to lock test

Three types of timed test are possible:

(a) Standard count down timer (t)

Timed tests are performed over a timed period defined by parameter ‘t’ (also refer to Set-up
procedures 13).

(b) Polarization Index (PI)

PI is the ratio between the insulation resistance values recorded at 1 minute (assigned t1)
and at 10 minutes interval (assigned t2). i.e. after 1 minute and 10 minutes.

PI = 10 minute value/1 minute value

(c) Dielectric Absorption Ratio (DAR)

DAR is the ratio between the insulation resistance values at 30seconds (assigned t1) and at 60
second interval (assigned t2). i.e. after 30seconds and 60seconds.

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DAR = 60 second value/30 second value

O N‘

(

(

(

During all insulation tests the symbol will flash indicating that a test voltage is present.

(a) Insulation resistance testing – timed procedure (not MIT400, MIT405 or MIT480).

(Refer to Figures 7)

Step 1:

Connect test leads to
circuit

Screen B

Indicating a PI test)

Screen A

(Indicating insulation

test mode)

Screen C

Indicating DAR test)

Screen D

Indicating timed test)

Step 3:

PI, DAR, t or INS

Step 6:

Press TEST to abort if
required

1. Connect the test probes to the isolated circuit under test.

2. Turn the instrument ‘O
position either 50 V, 100 V, 250 V, 500 V or 1 kV.

3. Select the timed test (t) by pressing ‘PI/DAR/t’ function button repetitively until the
desired function is displayed.
Note: the test type defaults to insulation resistance when the range switch is moved.
See figure 7 screens B, C & D.

Figure 7 Insulation resistance – timed modes

by rotating the selector switch to the required test voltage

Step 4:

Press TEST and hold

Step 2:

Range selection

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PI

DA R

g

4. Once selected, press and hold the [TEST] button to start the test.

5. Use the LOCK [
‘DAR’ and ‘t’ automatically lock the test on for the duration of the test.

6. For timed tests, the test will run for the time period defined in Set-up (see Set-up

procedures 14). To abort the test early, press TEST or LOCK [

7. At the end of the tests, the voltage will be discharged.

(b) Insulation resistance testing – PI and DAR (not MIT400, MIT405 and MIT480)

The P
After 10 minutes a second test result is stored (t2). The resultant ratio is then displayed on
the screen.
The same procedure applies for the D
seconds, with the first result (t1) taken at 30 seconds and the second at 60 seconds (t2).

Results can be recalled to screen using the uA/v/s [ ] keys.
Note: DO NOT press PI/DAR/t [ ] as it will change the test mode and erase the current
results.

Figure 8 illustrates the t1 and t2 screens.

test will run for a period of 10minutes. After one minute a test result is stored (t1).

] button only for standard insulation resistance tests if required. ‘PI’,

] buttons.

timed tests, however the test duration is 60

Screen A

(Results

displayed at

the end of

timed test)

Screen B

(Resistance

displayed at T1)

Time interval
t1

Use to display
t1, t2 and

e

volta

Press TEST
to repeat the
test

If selector switch
is moved, test
defaults to INS
mode

Figure 8 Insulation test – timed mode

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10. MIT40X testing

The MIT40X has a selectable insulation test range from 10 V to 100 V in 1 V increments. The
test voltage selected is the nominal test voltage. e.g. If 10 V is selected the actual voltage at the
probe tip will be within the stated tolerance of ±1 V.

The MIT40X is supplied with a default setting of 10 V. This can be adjusted in the setup
procedure between 10 V and 100 V. To adjust the insulation test voltage refer to the Setup
procedure.

Testing is performed in exactly the same manner as a standard insulation test in section 9.1
above.

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11. C onti n ui ty testing [] and buz z e r [ ]

O N’

Test procedure

(refer to Figure 9)

Contact
indication

Step 2:

Lead null

Continuity test
current

Step 3:

Buzzer ON/OFF

Step 4:

Connect test
leads to

conductor(s)

Step 1:

Figure 9 Continuity test and buzzer

1. Turn the instrument ‘O

2. If required the test lead resistance can be set to Zero (null) by shorting the test leads
together and pressing TEST. The null [
achieved and the display will read 0.00 .

3. Press the [
sounder symbol will be shown on the screen display. The pass threshold is set to 2  by
default, but is adjustable, as defined in Setup, see section 13.

Note that the buzzer defaults to OFF on power-up.

] button to enable/disable the audible buzzer function. When enabled, the

by rotating the selector switch to the desired  position.

] symbol will show when this has been

4. Connect the test leads to the isolated conductor(s) under test.

5. Observe the test result, displayed automatically. The auxiliary display indicates the
actual test current (e.g. 205 mA. The maximum is defined in section 13, setup menu.

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Note: The test current displayed is the actual test current used during the test, which
will depend on the resistance of the circuit under test.

12. Resistance measurements (k Range)

(Except MIT40X and MIT480)

Test procedure (refer to Figure 10)

Step 2:

Connect leads
to conductors

Step 3:

Result displayed

Step 1:

Figure 10 Resistance – k range

1. Turn the instrument ‘ON’ by rotating the selector switch to the desired [k]
position.

2. Connec t the test lead s to the isolat ed conduc tors under te s t.

3. Observe the test result, displayed automatically.

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13. Capacitance measurements

(Except MIT400, 405, 410, 480)

13.1 Capacitance measurement procedure

(refer to Figure 11)

Step 4:

Distance

Step 2:

Connect test
leads

Step 3:

Test result

Step :1

Figure 11 Capacitance range

1.

Turn the instrument ‘ON’ by rotating the selector switch to the capacitance [μF]
position.

Connect the test leads to the isolated conductors under test.

2.

Observe the test result, displayed automatically.

3.

13.2 Distance measurement by capacitance

4. For the MIT481 and MIT485 instrument only, cable length is also be displayed in feet,
km, or kft, as defined in Setup. This is calculated from the stored capacitance value
(default
50 nF/km).

This can be adjusted in section 13 (Setup) from 40 nF/km to 60 nF/km.

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14. Setup options

The setup position permits the user to adjust various threshold values and default settings.
When SETUP is selected, the instrument firmware revision is displayed, followed by the buzzer
alarm threshold.

Displayed

symbol

Set top threshold for continuity

BUZ

Loc Lock button ON/OFF ON ON / OFF All

buzzer in ohms.
Buzzer sounds is result is less
than set value.

Meaning

Default

setting

2 

Setting

options

1, 2, 5, 10, 20 

Instrument

All

ISC

InS

t

diS

CAB

Set v

bt

Setup maximum continuity
short-circuit current .

Sets low threshold for insulation
test buzzer in Mohms. Buzzer
sounds is result is more than set
value.
Timer for insulation test. Test
will count down to 0 seconds.
Test is active during
countdown.
Setup units for distance
measurement
Setup cable capacitance in nF
(distance measurement)

Setup insulation resistance
voltage

®

Bluetooth
Paring setup

200 mA

0.5 M

1

minute

m

50 nF

10 V

- -

20 mA, 200 mA

(default

200 mA)

0,5, 1, 2, 5, 10,

20 M

1 to 10 minutes

(in 1 minute

increments

m (meters), ft

(feet)

40nF to 60nF

1nF increments

10V to 100V

1 volt

increments

All

MIT420 

MIT40X

MIT410 

MIT481

All

MIT481

MIT40X

MIT430
MIT485

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Lock symbol

Step 2:

Press

Step 3:

Press and hold

Step 4:

Save settings

Step 1:

Figure 12 Set up

Setup procedure (refer to Figures 12)

Turn the instrument ‘ON’ by rotating the selector switch to the Setup position. The

1.

firmware version is displayed prior to the first setting BUZ.

Press the TEST button repeatedly to select the desired parameter, BUZ, Loc, ISC etc.

2.

When the function to be changed is displayed, press and hold the TEST button to

3.

change the value. Each subsequent press increments the limit. Holding down the TEST
button will automatic ally increment.

Changing a value will start the lock [ ] symbol flashing. This indicates a value has been

4.

changed but not saved.

Save new limit by pressing the Lock [ ] button. Saved changed are effected when the

5.

Screen Lock symbol stops flashing and disappears.

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15. Saving, recalling and downloading test results.

(MIT420, MIT430, MIT481 and MIT485)

15.1 Saving test results

After completing any test the result remains displayed on the screen for one minute. During
this time the result may be saved in memory and recalled later.

Step 1:

Screen A result

Step 2:

Press STORE

Figure 13 Test results storage

Procedure for storing test results (refer to Figure 13)

1.

After completion of a particular measurement, ensure the test result is displayed on the
instrument display, refer to Figure 13 Screen A.
The test result will remain displayed for one minute during which time the result may
be stored.

Press [STORE] to record the test result. A unique identification number is allocated to

2.

each test result which is displayed for 15 seconds before returning to the test result.

Result is now stored.

3.

15.2 Test results recall

(MIT420, MIT430, MIT481 and MIT485)

All stored test results may be recalled to the screen.

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Procedure for recalling stored test results

(refer to Figure 14)

Memory usage
indicator

Step 2:

Test result
number

Step 3:

Press for
Previous/Next

Step 4:

Press to view
result

Units of stored
test

Step 1:

Switch to RCL

Figure 14 Recall test results

1.

Turn the instrument ‘ON’ by rotating the selector switch to the recall (RCL) position.

Observe the latest unique test result identification number displayed. Where no results

2.

have previously been stored, the display will indicate this by three dashes.

Press [OK] to display last stored result, or select the particular test result identificatio n

3.

number by using the [] and [] buttons, then press ‘OK’ to select.

The test result will be displayed. Additional information stored with the test result may

4.

be viewed using the relevant button. For example on insulation test μA can be recalled
using the μA/S/V key. The TRMS key will operate on voltage results.

15.3 PI and DAR recall.

Additional recall information is ava ilable if the result stored was a PI or DAR test, as the result
is a ratio of two measured values.

Figure 15 illustrates the displays, which will be shown during a Dialectic Absorption Ratio
(DAR) test result recall.

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Screen A -

DAR

Screen B – t2

Screen C – t1

Step 2:

Select

result

Step 1:

Switch to RCL

Figure 15 DAR recall results

Screen D – VOLTAGE

Screen E – ID

To recall a PI or DAR result:

1. Rotate the selector switch to the recall (RCL) position and observe the latest unique

test result identification number displayed.

2. Locate the particular test result identification number by using the [] and []

buttons, then press ‘OK’ to select.

3. The test result will be displayed. To scroll through the different measurements used

in calculating the PI or DAR ratio, use the [] only button. See figure 15 screens B to
E.

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16. Deleting test results

(MIT420, MIT430, MIT481 and MIT485 only)

Stored test results may be deleted singularly or all together.

16.1 Procedure for deleting a single test result (refer to Figure 16)

Memory
usage

indicator

Step 2:

Check
correct

record

Step 3:

Press OK to
delete

Step 1:

Switch to DEL

Step 4:

Observe ‘new’ last
test result ID

Figure 16 Deleting a single test result

1.

Turn the instrument ‘ON’ by rotating the selector switch to the delete [DEL] position.
The latest test result will be displayed. Where no results have previously been stored, the

2.

display will indicate this by three dashes.

Press ‘OK’ to delete the displayed test result.

3.

Observe the ‘new’ last test result identification number, which may be deleted as

4.

previously described.

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16.2 Procedure for deleting all test results (refer to Figure 17)

Screen B

Screen A

Step 2:

Press
‘Next’ –
Screen B

appears

Step 3:

Press OK to
delete all stored

test results

Screen C

Step 1:

Switch to DEL

Figure 17 Deleting all test results

1.

Turn the instrument ‘ON’ by rotating the selector switch to the delete [DEL] position.
The latest test result will be displayed. Where no results have previously been stored, the
display will indicate this by three dashes.

Press next ( ) button. Note that the display now indicates ‘ALL’

2.

Press ‘OK’ to delete all the test results. Note the progress bar decays as the contents of

3.

memory a re deleted.

On completion of the deletion progress the display indicates three dashes signifying

4.

that no result remains stored. See figure 17 screen C.

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Fro m

From

“bt ”

16.3 Downloading test results

Preparing your MIT430 or MIT485 for “Bluetooth” Communications.

“Megger Download Manager” software and a computer with “Bluetooth” capabilities are
required to communicate with MIT430 and MIT485 instrument. Notes on installing these
options are explained in the document “Additional Bluetooth Information” which can be
found on the User CD. Run “Megger Download Manager” from the Windows start menu.
Enable the Bluetooth function on your PC. Refer to your PC manual if necessary.

Select Megger “MIT430 + MIT485” product by clicking the icon as shown. Load the
properties screen by clicking the “Properties Button”.

Click on the Bluetooth tab to display the current Bluetooth configuration.

The preferred method is to Pair F
detail below. Users familiar with “Bluetooth” devices may wish to “Pair “F
case “Open” your “Bluetooth Manager” usually located in the “Status Bar”. Switch your
MIT430 / MIT485 to “SETUP” and follow the procedure for “Scan for new devices”. Once the
MIT430 / MIT485 has been located Pair up using the Pin 1234. On IBM laptops use “Fn” with
“F5” to access “Bluetooth Services”.

the MIT430 / MIT485 TTo the PC. As described in in

Properties
Button

the PC. In this

Procedure for Pairing your MIT430 or MIT485 to your PC.

1. Switch the MIT430 / MIT485 Range Switch to the “Setup” position.

Scan for local “Bluetooth” computers. Press the yellow test button 5 times until the

2.

MIT430 / MIT485 displays “
(The three dashes indicate that the instrument has not yet been paired with a p.c.,
otherwise the current paired Bluetooth device ID will be displayed).

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Now press and hold the test button until you see the “<” and “>” symbols oscillating.

3.

Release the test button. The MIT430 /485 will search for “Bluetooth” computers. At the
end of this search, the total number of “Bluetooth” devices will be shown on the main
display. The partial address of the last detected device will be shown on the auxiliary
display.

Total
number of
Bluetooth
devices

4. Use the keys to scroll round and locate the address that matches the required
one shown on Download manager window.

5. With the required address displayed (the three-digit code should match the one
displayed on the properties screen) pair the module by pressing the test button until
the < > symbols on the auxiliary display alternate.

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Alwa ys allow

A message bubble may also be displayed on the pc against the Bluetooth icon.

6.

Click on this message and enter a Passkey of “1234” to accept the connection of the

7.
test instrument. (You may also need to accept other message prompts that may be
displayed as part of this setup sequence) If you get a message bubble or prompt
asking you to accept a serial port connection then click and accept, ticking the
“A

When complete the display will indicate “End”.

8.

” check box if available.

9. The MIT430 / MIT485 must now be switched to “OFF” after pairing to complete the
process.

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Standard Download Operation

Having completed the initial installation and pairing, future downloads to the nominated PC
becomes a very straightforward operation as described in the following simple steps.

a)

Run Megger Download Manager from the Windows start menu or short cut.

b)

Click once on the “Megger MIT430 + MIT485” icon.

c)

Click on the download button.

d)

Switch the instrument to the SND position to initiate the communications port and start
the download. (The download may take a few seconds to start if you have the Auto
Detect serial port option set in Download Manager properties screen).

Additional messages may appear to allow MIT to communicate. These should be

accepted.

e) After successful file transfer the MIT430 MIT485 will display “End”.

f)

The MIT430 / MIT485 should be switched to “OFF”.

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17. Battery and fuse replacement

(refer to Figure 18)

Figure 17

17.1 Battery condition and replacement

The battery condition indicator is displayed at all times that the instrument is switched on, as
below: 100%, 75% and 50%

Replacement batteries type is: 5 x LR6 (AA), 1.5 V Alkaline, or 5 x 1.2V NiMH

Note: NiMH or NiCAD rechargeable batteries show a lower charge than Alkaline batteries, and
may not give much warning before becoming exhausted.

Procedure to replace batteries

Warning: Do not switch the instrument on with the battery cover removed.

1. The rear cover must not

2. Switch off the instrument and disconnect (the instrument) from any electrical circuits.

3. To avoid the possibility of electric sho ck, do not

fuse when changing batteries.

4. To remove the rear cover, remove the screws from the rear of the battery cover, lift the

cover off.

5. Remove the dead cells and refit new batteries, observing the correct polarity as marked

on the battery compartment.

6. Replace the cover and retaining screws.

Warning: - Incorrect battery cell polarity can cause electrolyte leakage or damage the
instrument. If the battery condition indicator does not show a full charge, a cell may be
reversed.

be opened if the test leads are connected.

press the test button or touch the

Note: Battery cells should not be left in an instrument, which may remain unused for an
extended period.

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mus t

17.2 Blown fuse indicator

Figure 21 shows the blown fuse indicator which operates on continuity [] range. The
symbol will operate if the fuse has blown after contact with a live supply has occurred. A
blown internal fuse will be shown by the symbol flashing until the instrument is switched off.

Figure 21

Fuse replacement procedure (user replaceable)

The fuse is located behind the rear cover (see Figure 3). The rear cover must not
if test leads are connected.

Follow the same procedure as for battery replacement.

A replacement fuse m
i.e. 500 mA (FF) H.B.C.50 kA min 1000 V (32mm x 6mm)

be opened

be of the correct type and rating:

18. Preventive maintenance

The MIT400 series instruments require very little maintenance.

Test leads should be checked before use to ensure there is no damage.

Ensure batteries are removed if the instrument is left unused for an extended period.

When necessary, the instrument can be cleaned with a damp cloth.

The rubber boot can be removed to aid cleaning.

Do not use alcohol, based cleaners as these may leave a residue.

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19. Specification

All quoted accuracies are at +20 °C.

Insulation

Nominal test voltages

MIT400, 405 250 V, 500 V, 1000 V
MIT410, 420,430 50 V, 100 V, 250 V, 500 V, 1000 V

MIT480 50 V, 100 V
MIT481, 485 50 V, 100 V, 250 V, 500 V, 1000 V
MIT40X 10 V to 100 V variable (1 V increments)

Range full scale accuracy (Model dependant)

All ranges ±2% ±2 digits up to 100 M.

Then: 1000 volts ±3% ±2 digits ±0.2% per G

500 volts. ±3% ±2 digits ±0.4% per G
250 volts. ±3% ±2 digits ±0.8% per G
100 volts. ±3% ±2 digits ±2.0% per G
50 volts. ±3% ±2 digits ±4.0% per G
Analogue range 1 G full scale

Analogue range: 1 G full scale

Short circuit current:

Terminal voltage: -0% +20% ±1 V (I i <1 mA)

Test current on load: 1 mA at min. pass value of insulation specified in BS7671,

EN61557 operating range: 0,10 M to 1,00 G

Leakage current range: 10 μA to 2000 μA

Leakage current: 10% ±3 digits

Voltage display: 3% ±3 digits ±0.5% of rated voltage

Polarisation Index (PI): 10min / 1minute ratio

Dielectric absorption Ratio (DAR): 60sec / 30sec ratio

Notes:

(1) All ranges measure from 0,00 M upwards.
(2) Above specifications only apply when high quality silicone leads are being used.

Continuity

EN61557 operating range:
Accuracy:
Open circuit voltage:
Test current:

20 mA (±1 mA) (10.0  to 99.9 )

Zero offset at probe tips:

2 mA +0% -50%

HD384 and IEC364, EN61152-2, 2 mA max.

0,01  to 99,9  (0 to 100  on analogue scale)
± 2% ± 2 digits (0 to 100 )
5 V ± 1 V

205 mA (±5 mA) (0.01  to 9.99 )

0,10  typical

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Lead resistance zeroing:
Buzzer:

Resistance

EN61557 operating range:
Accuracy:
Open circuit voltage:
Short circuit current:

Voltage range

Default Voltmeter

Frequency:

(100Hz to 400Hz)

Capacitance measurement

MIT420, MIT430, MIT481 and MIT485.
Measurement range: 100 pF to 10 μF
Accuracy: ±5.0% ±2 dig its

Distance by capacitance:

MIT420, MIT430,MIT481, MIT485

Arithmetic conversion from capacitance measurement

Default capacitance distance measurement: 50 nF/km
Capacitance range: 40 nF/km to 60 nF/km

Result storage:
Capacity: >1000 test results
Download: Bluetooth wireless
Bluetooth class: Class II
Range: up to 10m

Power supply:

Battery life: 2200 insulation tests with duty cycle of 5 sec on 55 sec OFF

Dimensions:

Instrument 220 x 92 x 50 mm (8.66in x 3.63in x 1.97in)
Instrument + case 456 x 178 x 89mm (18in x 7in x 3.5in)

Weight:

Instrument only 590gms, 775gms with boot (20.73oz (27.22oz))
Instrument plus case 1.75kg (3.86lb)

0 to 600 V d.c. ± 2% ± 2 digits

15-400Hz (15Hz - 99,9Hz) ±0.5% ±1 digit

Up to 9,99 
Variable limit 1 , 2  , 5 , 10 , 20 

0,01 k to 1000 k (0 to 1 M on analogue scale)

±3% up to 50 k then ±5% ±2 digits

5 V ±1 V

1.5 mA ±0.2 mA

10 mV to 600 V TRMS sinusoidal (40 – 400 Hz) ±2% ±2 digits
0 to 1000 V on analogue scale
Unspecified input level 0 – 10 mV (40 – 400 Hz)
For non sinusoidal waveforms additional specifications
apply:
±3% ±2 digits 101 mV – 600 V TRMS and
±8% ±2 digits 10 mV – 100 mV TRMS

Operates at >25 volts a.c. or d.c., on any range except OFF

5 x 1,5V cells type IEC LR6 (AA, MN1500, HP7, AM3 R6HP)
Alkaline NiMH rechargeable cells may be used.

@ 1000 V into 1 M

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Use only a 500 mA (FF) 1000 V 32 x 6 mm ceramic fuse of high breaking capacity HBC

Fuse:
50 kA minimum. Glass fuses MUST NOT

Safety Protection

The instruments meet IEC 61010-1 to 600 V phase to earth, Category IV. *
Refer to safety warnings (see section 2).
*MIT 405 IEC 61010-1 600 V phase to earth Category III

Application

IEC 61010 defines measurement categories from I to IV relating transient over voltages and
the location within electrical installations. This instrument is designed for use at Category IV
(Primary supply level) on 600 V phase to earth systems.

E.M.C.

In accordance with IEC 61326-1

Temperature effects

Temperature coefficient <0,1% per °C up to 1 G

<0,1% per °C per G above 1 G

Environmental

Operating range: -20ºC to +55 °C
Operating humidity: 95% RH at 0ºC to +35ºC, 70% RH +35ºC to +55ºC
Storage temperature range: -30ºC to +80 °C
Calibration Temperature: +20 °C
Maximum altitude: 2000 m
Dust and water protection: IP54

be fitted.

20. Basic and service errors

The basic error is the maximum inaccuracy of the instrument under ideal conditions,
whereas the service error is the maximum inaccuracy taking into effect of battery voltage,
temperature, interference, system voltage and frequency, where applicable.

20.1 Basic error: See section 19

20.2 Service error:

Insulation range ±15% ±2 digits

Continuity range ±26% ±2 digits
Resistance range ±12% ±2 digits
Voltage range ±10% ±2 digits
Capacitance range ±18% ±2 digits
Distance range ±18% ±2 digits
Frequency range ±5% ±2 digits

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21. Accessories

Includes accessories

2 wire test lead set and crocodile clips 6220-813
SP5 Remote switch probe (not MIT400, 405, 40X, 480) 6220-812
Owner’s information CD 6172-965
Calibration certificate
Quick start guide 5270-923
Rubber boot 6231-802
Instrument case 5410-420

Additional in MIT430 and MIT485

Download Manager CD 6111-442

Optional accessories and replacements

Fused 2 wire test lead set and crocodile clips 6220-789

Bluetooth
Bluetooth

QPLN Reference: Q11406_WT12_SGS

“Contains Transmitt er Mod ule FCC ID: QO QWT12”

Module qualifications details
identifier: B02872

The Bluetooth word mark and logo are owned by the Bluetooth SIG, Inc. and any use of such marks by
Megger is under license.

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