MIT515, MIT525, MIT1025, MIT1525
5 kV, 10 kV, 15 kV DC Insulation Resistance Testers
MIT515, MIT525, MIT1025, MIT1525
5 kV, 10 kV, 15 kV DC Insulation Resistance Testers
DESCRIPTION
Megger’s range of DC insulation testers MIT515, MIT525, MIT1025
and MIT1525 are targeted at original equipment manufacturers
and industrial companies. The top of the range MIT1525 performs
insulation resistance tests up to 15 kV with a 30 TΩ maximum
resistance and an accuracy of ±5% to 3 TΩ. The MIT515 offers IR,
DAR and PI functions but has no memory functionality. MIT525,
MIT1025 and MIT1525 have a full suite of test modes as well as on-
board memory and the ability to stream data/download data to a PC/
laptop.
Instrument productivity is a focus of the new MIT range which
offers rapid charge batteries and operation from an AC source if the
batteries are dead. Rapid charge batteries enable > 60 minutes testing
after a 30 minute charge.
Safety is not compromised on the MIT range with all terminals rated
to CATIV 600 V to 3000 m (5 kV and 10 kV) or CATIV 1000 V to
3000 m (15 kV). A range of 5 kV and 10 kV test leads are available
plus dedicated 15 kV test leads which are double insulated with clips
designed for 15 kV creepage paths. The 15 kV leads are supplied in
a backpack. Depending on local procedures or the results of a risk
assessment, suitably rated HV gloves and other personal equipment
may be a requirement while testing.
The MIT range share dual case design which includes a tough outer
case to protect the tester from knocks/drops and an inner fire
retardant case. The IP rating is IP 65 case closed eliminating moisture
and dust ingress.
An intuitive user interface ensures no lost time remembering how
to use the tester. Simplicity of operation is achieved with two rotary
switches and the large backlight display which enables multiple
results to be displayed simultaneously. A graphical quick start guide is
provided inside the lid to assist first time users.
Five preset voltage ranges are provided in insulation test mode, plus
a user settable lock voltage range. Voltage can be selected in 10-V
increments to 1 kV and 25-V increments above 1 kV. Preconfigured
diagnostic tests include Polarization Index (PI), Dielectric Absorption
Ratio (DAR), dielectric discharge (DD), Step Voltage (SV) and
ramp test.
The ramp function gradually increases voltage up to a selected level
while graphing current vs. voltage. Graphs can then be downloaded,
or streamed real time, to either the Power DB Lite software supplied
or the optional Power DB software. Graphs can then be compared to
example curves in IEEE 95-2002 to reveal a variety of faults difficult to
detect otherwise. Small defects can be easily detected without risking
the sudden large voltage increments produced by a Step Voltage test.
Monitoring the developing graph during test enables the operator
to terminate prior to breakdown, thereby reducing the possibility
of damage to already flawed insulation. These units are particularly
informative on polyester, asphalt and epoxy-mica insulations. They can
also test voltage suppression devices.
Advanced memory storage includes time/date stamping of results,
logging of data and recall of results to screen. A fully isolated
USB interface is used for safe transfer of data to Megger’s asset
management software; PowerDB Pro, Advanced and Lite packages.
Test leads are double insulated with clamps rated at 3 kV equivalent to
6 kV single insulation for the medium clip leadset and 5 kV equivalent
to 10 kV single insulation for the large clip. The 15 kV leadset is
insulated to 15 kV.
30 TΩ maximum resistance
Unique dual-case design provides additional
user protection
Operate from battery or AC source
Rapid charge Li-ion battery
Safety rated CATIV 1000 V to 3000 m (15 kV)
Advanced memory with time/date stamp
MIT515, MIT525, MIT1025, MIT1525
5 kV, 10 kV, 15 kV DC Insulation Resistance Testers
FEATURES AND BENEFITS
Insulation resistance up to 30 TΩ @ 15 kV, 20 TΩ @ 10 kV,
10 TΩ @ 5 kV enables installation testing and long-term trending of
higher value apparatus, typically above 1 TΩ.
High altitude operation up to 3000 m while maintaining CATIV 600
V (5 kV and 10 kV) and CATIV 1000 V (15 kV).
5% accuracy all the way up to 1 TΩ @ 5 kV, 2 TΩ @ 10 kV, and
3 TΩ @ 15 kV ensures highest accuracy where it matters most.
Note: the majority of measurement in substation environments are
typically above 100 GΩ.
IR, timed IR, DAR, PI, DD, SV and ramp tests maximize diagnostic
testing capability.
3 mA short circuit current with unique max power regulations
technology ensures maximum transfer whatever the load until
selected voltage is reached.
Noise filter rejects up to 3 mA (5 kV and 10 kV) and 6 mA (15 kV)
noise for effective operation in electrically noisy environments.
Li-ion battery allows up to 6 hrs continuous testing @ 5 kV with a
100 MΩ load; battery meets IEC 62133.
Large backlit LCD, convenient for use in ambient lighting, clearly
shows analog and digital readings.
Dedicated voltmeter function (30 V to 660 V) allows the user to
check for induced volages.
Smaller size and lighter weight allows easier transport and use
without compromising performance.
Unique dual case design allows for fire-retardant protection while
maintaining ruggedness.
High-quality, flexible silicon test leads meet safety regulations of IEC
61010-31:2008 while ensuring measurement accuracy.
Timed IR plus PI, DAR, DD, SV and ramp tests maximize diagnostic
testing capability.
Operate from line power even if the battery is fully discharged
(charges while operating).
Two and one-half hour full battery charge time (one-half hour
charge for one hour testing) significantly increases productivity.
Up to six hours continuous testing (5 kV) on a single battery charge.
Industry best guard terminal performance to insure highest accuracy
of measured values.
Enhanced driver technology provides plug-and-play when
connected to the internet. No tedious and potentially interruptive
setup procedures.
Rotary switch operation for easy, intuitive field use.
Locking test leads provide additional safety.
Date and time-stamped test results reduce the risk of error in result
interpretation.
APPLICATIONS
The Insulation Resistance (IR) test is a quantitative test which indicates
the effectiveness of a product’s electrical insulation. Applications
include cables, transformers, motors/generators, circuit breakers and
bushings.
The units are designed for testing the insulation of high-voltage
electric equipment. Their wide voltage range also allows applications
for low-voltage equipment. The test techniques on the instruments
provide valuable diagnostic information.
All four instruments test the insulation resistance of:
High-voltage power cables and high-voltage buses
Large motor/generator windings
Line and substation transformers
The MIT525, MIT1025 and MIT1525 also perform spot tests, step-
voltage tests, dielectric discharge tests, ramp tests, and dielectric
absorption tests for the following applications:
Acceptance testing at installation to check conformance to
specifications.
Routine preventive/predictive maintenance testing after installation.
QA testing as part of the manufacturing process.
Diagnostic testing to isolate faulty components for repair.
IEEE Standard 43:2000
With its higher voltage testing capability, the MIT1025 is the perfect
everyday work tool for manufacturers, users and maintainers of
rotating machinery. Designed in accordance with the requirements
of IEEE43:2000, the MIT1025 is ideal for measuring the insulation
resistance of armature and field windings in rotating machines
rated 1hp (750 W) or greater. The standard applies to synchronous,
induction and dc machines as well as synchronous condensers.
In March 2000, the IEEE-SA Standards Board approved a revision of
IEEE Std 43-1974 by the Electric Machinery Committee of the IEEE
Power Engineering Society. This revision is IEEE Std 43-2000, the
“IEEE Recommended Practice for Testing Insulation Resistance of
Rotating Machinery.” Following are the testing recommendations
from the standard:
Test voltages up to 10 kV are recommended for windings rated
greater than 12 kV.
Both the insulation resistance and the polarization index tests are
recommended.
15 kV Insulation Testing
A 15 kV insulation test is recommended for higher voltage
electrical equipment. The Pearl Reconditioning Standard / NETA
MTS-1997 defines both the minimum dc test voltage and minimum
recommended insulation resistance based on the maximum voltage
rating of the equipment being tested. For equipment rated from
35 kV to 69 kV, 15 kV dc test voltage should be used. The minimum
recommended insulation resistance is 100 GΩ.
NETA ATS 2007 Section 7.15.1 defines test voltage and minimum
insulation resistance for ac induction motors and generators. If the
voltage rating of motor’s winding is 34.5 kV, a 15 kV dc test voltage
should be used. Again, the minimum recommended insulation
resistance is 100 GΩ.
The MIT1525 maintains ±5% accuracy up to 3 TΩ, which is well
above the minimum recommended insulation resistance level in both
standards.
SPECIFICATIONS
Electrical
Voltage input range:
5 kV, 10 kV 90-264 V rms, 47-63 Hz, 100VA
15 kV 90-264 V rms, 47-63 Hz, 200VA
Battery: 11.1 V, 5.2Ah Li-ion batteries,
meet IEC 62133:2003,
MIT1525 has 2 battery packs
Battery life MIT515, MIT525: 6 hours (typical) continuous testing
at 5 kV with a 100 MΩ load
Battery life MIT1025: 4.5 hours (typical) continuous testing
at 10 kV with a 100 MΩ load
Battery life MIT1525: 4.5 hours (typical) continuous
testing at 15 kV with a
100 MΩ load
Battery charge time: 2.5 hours from deep discharge,
2 hours normal discharge
Test voltages MIT515, MIT525: 250 V, 500 V, 1000 V, 2500 V,
5000 V, VL
Test voltages MIT1025: 500 V, 1000 V, 2500 V, 5000 V,
10,000 V, VL
Test Voltages MIT1525: 1000 V, 2500 V, 5000 V,
10,000 V, 15000 V, VL
Lock test voltage VL: 40 V to 1 kV in 10 V steps,
1 kV to 5 kV in 25 V steps,
5 kV to 15 kV in 25 V steps
Voltage o/p accuracy: +4%, -0%, ±10 V nominal test
voltage at 1GΩ load (0°C to 0°C)
Resistance Range: 10 k to 10 TΩ @ 5 kV
10 k to 20 TΩ @ 10 kV
10 k to 30 TΩ @ 15 kV
Accuracy (23 °C) from 1 MΩ to:
MIT515, MIT525 ±5% to 1 TΩ, ±20% to 10 TΩ
MIT1025 ±5% to 2 TΩ, ±20% to 20 TΩ
MIT1525 ±5% to 3 TΩ, ±20% to 30 TΩ
MIT515, MIT525, MIT1025, MIT1525
5 kV, 10 kV, 15 kV DC Insulation Resistance Testers
Centrally positioned guard ring: Guard parallel leakage,
resistance down to 250 kΩ with
a maximum additional resistance
error of 1% with a 100 MΩ load.
Display range analog: 100 kΩ to 10 TΩ
Display range digital: 10 kΩ to 30 TΩ
Short circuit current: 3 mA @ 5 kV, 10 kV, 15 kV
Insulation alarm: 100 kΩ to 10 GΩ
Capacitor charge: < 3 s/μF to 5 kV, < 5 s/μF to
10 kV, < 7.5 s/uF to 15 kV
Capacitor discharge: 5 kV to 50 V :< 120 ms/μF
10 kV to 50 V:< 250 ms/μF
15 kV to 50 V:< 3500 ms/μF
Capacitance range (> 500 V): 10 nF to 50 μF (dependent on
measurement voltage)
Capacitance accuracy (23 °C): ±10% ±5 nF
Current measurement range: 0.01 nA to 6 mA
Current measurement accuracy: ±5% ±0.2 nA at all voltages (23 °C)
Interference (noise) rejection:
MIT515, MIT525 3 mA from 450 V to 5 kV
MIT1025 3 mA from 960 V to 10 kV
MIT1525 6 mA from 2100 V to 15 kV
Voltmeter range: 30 V to 660 V ac or dc,
45Hz – 65Hz
Voltmeter accuracy: ±3%, ±3V
Timer range: Up to 99 minutes 59 seconds,
15 second minimum setting
Memory capacity: 5.5 hours logging @ 5 sec intervals
Test regimes: IR, IR(t), DAR, PI, SV, DD, ramp test
Interface: USB type B (device)
Real time output: 1 Hz output readings (V, I, R)
Environmental
Altitude: 3000 m
Operating temperature: -4° F to +122° F (-20° C to 50° C)
Storage temperature: -13° F to +149° F (-25° C to 65° C)
Humidity: 90% RH non-condensing at 40 °C
Ingress protection: IP65 (lid closed), IP40 (lid open)
Safety
CAT Rating: CATIV 600 V to 3000 m (5 kV, 10 kV)
CATIV 1000 V to 3000 m (15 kV)
EMC: Meets the requirements of
IEC 61010-1 and IEC61326-1
Dimensions
MIT515, MIT525, MIT1025 12 in. L x 11 in. W x 7 in. H
(315 mm L x 285 mm W x 181 mm H)
MIT1525 14 in. L x 12 in. W x 8 in. H
(360 mm L x 305 mm W x 194 mm H)
Weight
MIT515, MIT525, MIT1025 10 lb (4.5 kg)
MIT1525 14 lb 6.5 kg
Model MIT1025 Panel
MIT515, MIT525, MIT1025, MIT1525
5 kV, 10 kV, 15 kV DC Insulation Resistance Testers
MIT515, MIT525, MIT1025, MIT1525
5 kV, 10 kV, 15 kV DC Insulation Resistance Testers
Product Comparison Guide for 5/10/15-kV Insulation Testers
Model Number MIT515-US MIT525-US MIT1025-US MIT1525-US
Cat. Number 1001-936 1001-940 1001-944 1002-909
Display Analog/Digital
Power Supply Line power
Rechargeable
Lock test
voltage VL
Test Voltage
15.0 kV
10.0 kV
5.0 kV
2.5 kV
1.0 kV
500 V
250 V
10 V steps 40 V to 1 kV
25 V steps 1 kV to max test voltage
1 kV to 15 kV in 25 V steps for 15 kV
10 V steps 100 V to 1 kV
25 V steps 1 kV to max test voltage
Measurements
Max. reading 10 TΩ10 TΩ20 TΩ30 TΩ
Min. reading 10 kΩ10 kΩ10 kΩ10 kΩ
Voltage
Capacitance and time constant
Leakage current
Test Types
Auto IR
Auto PI
Auto SV
Auto DD
Auto DAR
Auto ramp test
Other Features
Safety rating CAT IV 600 V CAT IV 600 V CAT IV 600 V CAT IV 1000 V
Timer control
Timer display
3mA short circuit currents
USB output (cable included)
Calibration certificate included
IP65 rating case closed
Alarm limit mode
Compatible with Power DB
User programmable lock voltage
range
Real time clock
Battery charge time max (hours) 2.5 2.5 2.5 2.5
Noise rejection 3 mA 3 mA 3 mA 6 mA
Guard terminal performance 2% error guarding 500 kΩ leakage with a 100 MΩ load
UK
Archcliffe Road Dover
CT17 9EN England
T +44 (0) 1304 502101
F +44 (0) 1304 207342
UKsales@megger.com
OTHER TECHNICAL SALES OFFICES
Dallas USA, College Station USA, Sydney
AUSTRALIA, Danderyd SWEDEN, Ontario
CANADA, Trappes FRANCE, Oberursel
GERMANY, Aargau SWITZERLAND, Dubai
UEA, Mumbai INDIA, Durban SOUTH AFRICA,
Chonburi THAILAND, Malaga SPAIN
CERTIFICATION ISO
Registered to ISO 9001:2008 Cert. no. Q 09250
Registered to ISO 14001-2004 Cert. no. EMS 61597
MIT515-525-1025-1525_DS_USen_V01
www.megger.com
Megger is a registered trademark
Information herein subject to
change without notice
MIT515, MIT525, MIT1025, MIT1525
5 kV, 10 kV, 15 kV DC Insulation Resistance Testers
ORDERING INFORMATION
Item (Qty) Cat. No.
MIT515-US 1001-936
MIT525-US 1001-940
MIT1025-US 1001-944
MIT1525-US 1002-909
Included Accessories
Power lead
USB cable
PowerDB Lite software
Product Information CD
3 m leadset x 3, medium insulated clips 1002-531
3 m leadset x 3, large insulated clips
(MIT1025 only)
1002-534
3m leadset x 3, large 15 kV insulated clips
(MIT1525 only)
1002-949
Optional Accessories
1 kV test lead sets
Fused test probe and clip lead set 1002-913
Control circuit test lead set 6220-822
Item (Qty) Cat. No.
HV test lead sets 5kV, 10kV
5 m leadset x 3, large insulated clips* 1002-645
8 m leadset x 3, large insulated clips 1002-646
10 m leadset x 3, large insulated clips 1002-647
15 m leadset x 3, large insulated clips 1002-648
5 m leadset x 3, medium insulated clips* 1002-641
8 m leadset x 3, medium insulated clips 1002-642
10 m leadset x 3, medium insulated clips 1002-643
15 m leadset x 3, medium insulated clips 1002-644
3 m leadset x 3, bare compact clips 8101-181
8 m leadset x 3, bare compact clips 8101-182
15 m leadset x 3, compact bare clips 8101-183
* These test leads may also be supplied in non-standard lengths
to suit a particular application / requirement. Please contact
Megger for a quotation; minimum order quantities may apply.
Screened HV test lead sets
3 m, 5 kV screened un-insulated small clips 6220-835
15 m, 5 kV screened un-insulated small clips 6311-080
3 m, 10 kV screened un-insulated small clips 6220-834
10 m, 10 kV screened un-insulated small clips 6220-861
15 m, 10 kV screened un-insulated small clips 6220-833
Other
CB101, 5 kV Calibration Box 6311-077
Calibration Certificate - CB101 1000-113
MIT1525 shown with
15-kV insulated clip leadset
CATIV 1000 V rating on MIT1525 unit’s terminals, shown above. The MIT515, MIT525,
and MIT025 are rated CATIV 600 on all terminals.
Easy-to-read rotary switch buttons for
intuitive field use.
Large backlit LCD shows multiple
parameters simultaneously.
UNITED STATES
2621 Van Buren Avenue
Norristown, PA 19403 USA
T 1 866-254-0962 (USA only)
T +1 610-676-8500
F +1 610-676-8625
VFCustomerSupport@megger.com
(case sensitive email address)
