Megger MIT510 User Guide
Megger MIT510 User Guide
Megger MIT510 User Guide
MIT510
5kV Digital Insulation Tester
USER MANUAL
G SAFETY WARNINGS
NOTE
THE INSTRUMENT MUST ONLY BE USED BY SUITABLY TRAINED AND COMPETENT PERSONS.
Cleaning
Disconnect the instrument and wipe it with a clean cloth slightly damped with soapy water or Isopropyl alcohol (IPA).
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CONTENTS
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INTRODUCTION POWER LEAD AND CHARGING
The MIT510 is a compact microprocessor controlled high voltage d.c. If the power lead supplied is not suitable for your type of mains outlet, do
insulation tester, powered by internal rechargeable battery or mains not use an adaptor. Always use a power lead fitted with the correct plug.
supply. A comprehensive LCD display shows resistance, current,
NB: A plug severed from the power lead is a hazard if plugged into a live
capacitance, voltage and timer measurements digitally, with resistance
socket. Severed plugs must be destroyed immediately.
being shown in analogue as well.
The instrument is fitted with a two-pin IEC60320 power inlet. Most power
Features include:
leads are made with three-core cable so the ground connection will not
■ Resistance or current measurement- front panel selectable be used.
■ Resistance measurement range - 10 kΩ to 15 TΩ Power lead cable colour coding:
■ Front panel selectable test voltages - 250 V, 500 V, 1000 V, 2500 V, 5000 V
International USA
■ Incremental timer (minutes & seconds) – measures during test
Earth/Ground Yellow/Green Green
■ Load capacitance measurement – displayed at end of a test
■ LCD backlight – front panel selectable Neutral Blue White
■ Battery level/charging indicator Live (Line) Brown Black
■ Mains (line) input presence LED If using a fused plug ensure it is fitted with a 3 Amp fuse.
■ High voltage warning flashing LED shows when greater than 50 V
The instrument can be powered from 95 - 240 V rms, ±10% 50/60Hz.
present on test leads
With power connected the battery will charge as long as a test is not in
■ High voltage warning LCD "flash" shows when greater than 50 V progress. The Power On/Off button has a green LED which illuminates
present on test leads when mains power is present.
■ 8 hours continuous testing on full charge.
For best battery lifetime, charge the battery after each use. A completely
exhausted battery will take 14 hours to recharge.
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INSTRUMENT CONTROLS AND INDICATORS
Battery level
Analogue
Warning display
voltage at
terminals
Warning
voltage at
terminals
Digital
display
Time constant Capacitance display
2. To turn on, press Power On/Off button and release after display 8. To stop the test press TEST button.
responds. The instrument first will perform a self-check during which
9. Timer will stop.
Ini is displayed. After Ini disappears the instrument is ready for use.
3. Check voltage at terminals display to be sure the load is safe to 10. Analogue display shows insulation resistance.
energise. 11. Digital display shows resistance or current selected by pressing Ω/I
4. Set test voltage required with V▲ and V▼ buttons. button.
5. To start a test, press TEST button and release after red LED shows. If 12. Load capacitance will be calculated and displayed after the end of
external voltage at terminals <50 V, testing starts. the test.
6. TEST button red LED and display warning symbols will flash during a 13. Time-constant will be displayed after the end of the test.
test to show high voltage present at terminals.
7. Timer will count up from zero during test.
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Power On/Off button Test start / stop button
The instrument will only turn on if this button is pressed, held and then A test will only start if this button is pressed, held and then released as
released when the display responds. The instrument will not turn on if the soon as the red high voltage warning indicator LED lights. The LCD and
button is released before the display responds, or if the button is held red LED high voltage warning indicators flash when the test starts.
down for too long. This is a safety feature to prevent the instrument being
inadvertently turned on. A test will not start if the button is released before the red LED shows, or
pressed continuously for longer than 5 seconds. This is a safety feature to
The instrument is turned off either by pressing the button again, or if the prevent a test being started inadvertently.
instrument is running on the battery, by timing out after 10 minutes of
inactivity. The presence of a voltage greater than 50 V on the test leads is indicated
with flashing high voltage warning indicators. Testing is disabled if the
Upon switching the instrument on the display will first show ‘Ini’ while it external voltage exceeds 50 V.
undergoes a self-checking routine. When Ini disappears, the instrument is
ready for use. Testing will stop if the test start / stop button is pressed again.
Test voltage ▲ and ▼ buttons When a test has finished, the instrument will discharge the load, which
Using these buttons one of five test voltages can be selected: 250 V, 500 V, may take some time. The operator must always check the load has been
1 kV, 2.5 kV, and 5 kV. The selected voltage is shown on the display. discharged before touching the test leads.
If there is an external voltage greater than 50 V on the test leads, the high Ω/I button
voltage warning indicators are flashed, and the display shows this voltage Pressing this button toggles the digital display between the insulation
instead. The instrument will not perform a test if this voltage is greater resistance and current.
than 50 V.
B button
During a test the display shows the actual voltage on the test leads. If the Pressing this button toggles the display backlight on and off.
test voltage is changed during a test, the new test voltage will be displayed
briefly. High voltage warning LED
When the test has stopped, the display continues to show the voltage This is a red LED next to the TEST button on the front panel. The LED
present on the test leads. Pressing either test voltage ▲ or ▼ button will flashes when the voltage on the test inputs exceeds 50 V.
then display the test voltage immediately before the end of the test.
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Line input present LED
This is a green LED next to the power On/Off button on the front panel. It
is illuminated whenever the mains power is connected.
Test terminals
There are three test terminals marked +, - and G. These terminals are
designed to accept only the test leads supplied. Shutters across the
terminals prevent accidental ingress of dirt and other objects. Test lead
plugs interlock with the shutters and are released by rotating the test lead
plug a quarter turn. The guard terminal is at the same potential as the negative terminal. Since
the leakage resistance is effectively in parallel with the resistance to be
The Guard terminal is explained below and is only used in cases where measured, the use of the guard causes the current flowing through surface
surface leakage currents need to be eliminated. Most measurements use leakage to be diverted from the measuring circuit. The instrument
just the + and – terminals. The instrument’s internal voltage generator therefore reads the leakage of the insulator, ignoring leakage across its
drives the + terminal with respect to the – terminal, current being surface. The display will show ‘FUS’ if the internal guard terminal fuse is
measured in the – terminal. found to have blown. The instrument must be switched off to clear the
message before further testing is permitted. The fuse should be replaced
Guard terminal by an authorised repairer. The instrument may be used in the mean time if
For basic insulation tests and where there is little possibility of surface the guard terminal not used. Refer to notes regarding measurements
leakage affecting the measurement, it is unnecessary to use the guard above 100 GΩ on page 9.
terminal i.e. if the insulator is clean and there are unlikely to be any adverse
current paths. However in cable testing for example, there may be surface Factory programming socket
leakage paths across the insulation between the bare cable and the external This is a 9 pin socket under the hinged cover and is not for customer use.
sheathing due to the presence of moisture or dirt. Where it is required to
remove the effect of this leakage, particularly at high testing voltages, a
bare wire may be bound tightly around the insulation and connected via
the third test lead to the guard terminal ‘G’.
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Battery bar graph instrument will not perform a test. The high voltage warning indicators
This is a battery symbol on the LCD display comprising 4 pairs of flash, and the beeper sounds, to warn of the hazard until the external
segments. The battery is monitored continuously when the instrument is voltage becomes less than 50 V.
turned on. The charge remaining in the battery is shown in the table
below. When testing, the voltage displayed is the voltage present at the test
terminals of the instrument. If the test voltage is changed, by pressing
Fully charged battery either of the test voltage ▲ and ▼ buttons during a test, the new test
voltage is displayed momentarily.
50% charged battery After testing, the voltage displayed is the voltage present on the terminals.
To see what the voltage was immediately prior to the end on the test,
press either test voltage ▲ or ▼ buttons.
Tests cannot be started, and the battery may fail
at any time. Timer indicator
The timer shows minutes and seconds. At the start of a test the timer will
start from zero and at the end of a test it will stop. The duration of the last
Symbol flashes when there is not enough charge test remains on the display until another test is started.
for a test. The instrument then turns itself off
Digital Display
The digital display shows the resistance or current being measured during
a test. The Ω/ I button toggles between the two. After a test the display
When mains power is present the indicator shows the battery is being shows the last measurement made until the timer or voltage test settings
charged by animating the segments of the bar graph. are changed or the test start/stop button is pressed.
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Capacitance display If the guard lead is connected to ground, then since the negative terminal
At the end of a test the capacitance of the circuit under test is calculated is at the same voltage as the guard terminal, the leakage into the negative
and displayed. After a test the display shows the last measurement made terminal will be considerably reduced. This will improve accuracy because
until the V▲, V▼, or TEST buttons are pressed. the current flowing into the negative terminal is measured by the
instrument and used to calculate resistance. This technique is only
Time constant: permissible if the item under test is isolated from ground. “Isolated” in
At the end of a test the time constant of the circuit under test is calculated this context means insulated by a resistance of at least 5 MΩ for the
and displayed. After a test the display shows the last measurement made positive terminal, or at least 10 kΩ for the negative terminal.
until the V▲, V▼, or TEST buttons are pressed.
Conversely, if the positive terminal is grounded, then the negative terminal
will be at a voltage equal to the test voltage relative to ground, which will
Measurements above 100 GΩ
result in an increase in leakage current, and worsening of measurement
Measurements up to 100 GΩ can be made without any special precautions,
accuracy.
assuming that the test leads are reasonably clean and dry. The guard lead
can be used to remove the effects of surface leakage if necessary. When
+ Test V 0V
measuring resistances above 100 GΩ, the test leads should not be allowed
to touch each other, or any other object since this will introduce leakage + -
paths. Sharp points at the test lead connections should also be avoided Guard
since this will encourage corona discharge.
Ground
The output is isolated, and so will float relative to ground such that the
positive terminal is at plus half of the test voltage, and the negative terminal
is at minus half of the test voltage with respect to ground. Leakages When making measurements above 100 GΩ therefore, the user should
therefore occur between the positive terminal and ground, between the ground the Guard Lead where possible, otherwise parallel leakage paths
negative terminal and ground, and directly between the positive and may occur.
negative terminals. These leakages have a significant effect and can occur
Alternatively, screened leads are available as an optional accessory from
through the air itself.
Megger. The lead to the negative terminal is fully screened. The screen is
+ Test V - Test V plugged into the Guard terminal, diverting any stray leakage currents. This
2 2 considerably improves measurements made with a floating output, where
+ -
the leads might touch each other or anything other than the test piece.
Ground
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SPECIFICATION
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Voltage output accuracy (0°C to 30°C) Humidity
+4%, -0% ±10 V of nominal test voltage at 1 GΩ load 90% RH non-condensing at 40°C
Interference rejection
1 mA rms per 250 V test voltage up to a maximum of 2 mA
Timer range
Counts up to 99 minutes from start of test
Test regimes
Auto IR
Lead set
Three flexible silicon insulated leads with compact clamp.
Safety
Meets the requirements of EN61010-1:2001 CAT III 300V
EMC
Meets the requirements of EN61326-1:1998 for use in heavy industrial
areas.
Operating temperature
-10°C to 50°C
Storage temperature
-25°C to 65°C
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ACCESSORIES
Order Code
Included Accessories
3 m lead set 8101-181
Optional Accessories
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REPAIR AND WARRANTY
The instrument contains static sensitive devices, and care must be taken in Returning your product to Megger - UK and USA service
handling the printed circuit board. If an instrument’s protection has been centres
impaired it should not be used, but sent for repair by suitably trained and 1. When an instrument requires recalibration, or in the event of a repair
qualified personnel. The protection is likely to be impaired if for example, it being necessary, a Returns Authorisation (RA) number must first be
shows visible damage, fails to perform the intended measurements, has obtained from one of the addresses shown above. You will be asked to
been subjected to prolonged storage under unfavourable conditions, or has provide the following information to enable the Service Department to
been subjected to severe transport stresses. prepare in advance for receipt of your instrument, and to provide the
best possible service to you.
NEW INSTRUMENTS ARE GUARANTEED FOR 1 YEAR FROM THE ■ Model, e.g. MIT510.
DATE OF PURCHASE BY THE USER.
■ Serial number, to be found on the underside of the case or on
Note: Any unauthorized prior repair or adjustment will automatically the calibration certificate.
invalidate the Warranty. ■ Reason for return, e.g. calibration required, or repair.
CALIBRATION, REPAIR AND SPARE PARTS ■ Details of the fault if the instrument is to be repaired.
For service requirements for Megger Instruments contact: 2. Make a note of the RA number. A returns label can be emailed or faxed to
you if you wish.
Megger Limited or Megger
Archcliffe Road Valley Forge Corporate Centre 3. Pack the instrument carefully to prevent damage in transit.
Dover 2621 Van Buren Avenue 4. Ensure the returns label is attached, or that the RA number is clearly
Kent CT17 9EN Norristown PA 19403 marked on the outside of the package and on any correspondence,
England. U.S.A. before sending the instrument, freight paid, to Megger. Copies of the
original purchase invoice and packing note should be sent simultaneously
Tel: +44 (0) 1304 502 243 Tel: +1 610 676 8579
by airmail to expedite clearance through customs. In the case of
Fax: +44 (0) 1304 207 342 Fax: +1 610 676 8625 instruments requiring repair outside the warranty period, an immediate
Megger operate fully traceable calibration and repair facilities, ensuring your quotation can be provided when obtaining the RA number.
instrument continues to provide the high standard of performance and 5. You may track the progress of your return on line at www.megger.com
workmanship you expect. These facilities are complemented by a worldwide
network of approved repair and calibration companies to offer excellent in-
Approved Service Centres
service care for your Megger products.
A list of Approved Service Centres may be obtained from the UK address
above, or from Megger’s website at www.megger.com
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