Megger MIT400 Series User manual

M
MIT400 Series
Insulation and continuity testers
USER GUIDE
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USER GUIDE CONTENTS
1. Introduction 3
2. SafetyWarnings 4
3. Symbolsusedontheinstrument 5
4. GeneralDescription 6
Unpackingthecarton 6
Cartoncontents(allinstruments) 6
5. Preparationsforuse(allinstruments) 7
Batteries 7
Preliminarytestleadcheck 7
6. General operating instructions 8
Generalfunctions 8
LCDDisplay 9
Backlightoperation 10
7. Testleadconnections 11
Standardtestleads 11
SP5 Switched probe (not MIT400, MIT480 and MIT40X) 11
8. AC/DC voltage and frequency measurements 12
9. Insulationresistancetesting-general 13
Standard insulation resistance testing 13
Insulation resistance testing – timed modes ‘t’, PI and DAR 14
10. MIT40Xtesting 17
11. Continuity testing [] and buzzer [ ] 18
12. Resistance measurements (kRange) 19
13. Capacitancemeasurements 20
Capacitance measurement procedure 20
Distance measurement by capacitance 20
14. Setupoptions 21
15. Saving , recalling and downloading test results. 23
Savingtestresults 23
Testresultsrecall 23
PIandDARrecall. 24
16. Deletingtestresults 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. Batteryandfusereplacement 32
Battery condition and replacement 32
Blownfuseindicator 33
18. Preventivemaintenance 33
19. Specification 34
20. Basicandserviceerrors 36
Basicerror 36
Serviceerror: 36
21. Accessories 37
22. RepairandWarranty 39
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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
MIT400 series insulation testers
Safety Warnings and Precautions must be read and understood before the instrument is
used. They must
be observed during use.
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.
2
Circuit connections and exposed-conductive-parts and other metalwork of an
installation or equipment under test must not be touched during testing.
3
The live circuit warning and automatic discharge are additional safety features,
which may fail, and therefore safe working practices must be observed.
4
The voltage function will only work if the instrument is functional and switched on.
5
After insulation tests, capacitive circuits must be allowed to discharge before
disconnecting test leads.
6
The instrument should not be used if any part of it is damaged.
7
All test leads, probes and crocodile clips must be in good order, clean and with no
broken or cracked insulation.
8
Ensure that hands remain behind guards of probes/clips when testing.
9
National Safety Authorities may recommend the use of fused test leads when
measuring voltage on high-energy systems.
10
Replacement fuses must be of the correct type and rating. Failure to fit the correctly
rated fuse may result in a safety hazard and may cause damage to the instrument in
the event of an overload.
11
The battery cover m
must
be in place whilst conducting tests.
N O TE
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
GCaution: 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
Functional 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.
2.
Check continuity of the test leads by firmly shorting the leads together and read the
test lead resistance measurement directly from the display, 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
Figure 3 Main features (MIT430 shown)
Figure 4 Function buttons (MIT430 shown)
Red test lead or
switched probe
Black Test lead
connection
Test button and
lead null
Insulation lock
button
Function
buttons
Battery/internal
fuse access
panel at rear
Result recall and
transfer
Insulation test
ranges
OFF positon
Resistance ranges
Capacitance (μF)
Insulation, PI test, DAR test
or timed test button Up/down buttons
μA/s/V button
Buzzer on/off
Backlight button
Store/last button
TRMS/DC button
Test button
Next button
LCD screen
Voltage range
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6.2 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 automatically 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.
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 [ ] button. Refer to figure 4.
The backlight function will switch off automatically after 20 seconds.
Multifunction
analogue display
Units of parameters on
auxiliary display
Battery condition
indicator
Audible alarm indicator
TRMS indicator
Units of parameters on
main display
Auxiliary digital display
Continuity indicator
Lock indicator
Warning – refer to
user manual
Fuse blown indicator
Out of range
indicator
Lead null indicator
Fi
g
ure 1 LCD displa
y
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