Major Megger
Insulation Resistance Testers
DESCRIPTION
Quality is crafted into every Major MEGGER® Insulation
Tester, with excellent test voltage regulation, direct
measurement readout and an external guard terminal to
eliminate surface leakage current from the measurement.
Five models are available for general purpose testing which
include a low-voltage model.
All are portable, self-contained instruments designed to give
rapid and accurate measurements.
Four of the models feature an analog display having four
selectable test voltages of 100, 250, 500 and 1000 Vdc,
measuring insulation resistance up to 2000 MΩ, and an ohm
range to 5000 ≈. The other model has four test voltages of
50, 100, 250 and 500 Vdc measuring insulation resistance up
to 1000 M≈.
The only other difference between the five analog models is
the type of power source. Power for models MJ159 and
MJ160 is derived from a low-voltage, hand cranked
generator which has been designed to be easy to turn even
under full load conditions. The low-voltage generator is
connected to an electronic inverter to provide a very stable
test voltage. Accuracy of measurement is unaffected by
variations in the generator cranking speed and the test
voltage is maintained at its rated value. Power for model
MJ359 is provided by 120 V ac 50/60 Hz or low-voltage
generator. Model MJ559 is also 120 Vac 50/60 Hz or internal
rechargeable batteries and model MJ459 is powered by 6
replaceable “AA” alkaline cells.
As a safety feature, the ac voltage range becomes effective as
soon as the instrument is connected to the circuit under
test. Therefore, a warning is given that the circuit under test
is not de-energized before the instrument is operated.
Though calibrated for ac voltage, this range also monitors
the automatic discharge feature so that after equipment
having capacitance (i.e. a cable), has been tested, an
indication can be given that the voltage has discharged to a
level that is safe for removing the test leads.
Each instrument has a guard terminal which may be used to
prevent the effects of surface leakage from influencing the
readings. This is achieved by diverting the leakage current
through the guard terminal and away from the instrument’s
measuring circuit.
Each instrument is built into a strong ABS plastic case with a
fold down carrying handle.
APPLICATIONS
The Major Meggers have been designed for convenience
and ease-of-use when testing complex or larger electrical
installations, and commissioning, servicing or maintaining
electrical equipment. They are designed for the safe testing
of motors, generators. cables, switchgear,transformers,
distribution networks, industrial and domestic installations,
components and appliances.
The range of insulation test voltages available allows one
instrument to be used for a variety of applications. For
example, installations and equipment can be tested at
nNoscale multipliers
nMultiple test voltages for spot and step
voltage testing
nGuard terminal to eliminate surface
leakage current
MJ TESTERS
Insulation Resistance Testers
1000 V d.c. when this requirement is specified, also aircraft
and tele-communications equipment can be tested at the
relatively low 100 V d.c. and 110 V to 120 V a.c. systems can
be tested using 250 V d.c.
Test leads with fused prods are available and it is
recommended that these be used when checking that
equipment has been isolated from the supply (by
performing a voltage test), especially in high energy
situations.
SPECIFICATION
Insulation Range
Insulation Resistance: 0.1 Ω- 2000 MΩ(0.1 Ω-1000 MΩfor
MJ160)
Accuracy: ±1.25% of fsd on a 2.8 in. (71.1mm) arc length
Nominal Test Voltages
d.c: 100 V, 250 V, 500 V, 1000 V.
(MJ160 is 50 V, 100 V, 250 V, 500 V)
Accuracy
250 V, 500 V, 1000 V +30%, -0% max.
50 V, 100 V, +40%, -0% max.
Midscale: 4 MΩ(2 MΩfor MJ160)
Short Circuit Current: 1.9 mA
(0.65 mA for MJ160)
Maximum Load Capacitance: 1µF with less than ±0.1" pointer
movement
Discharge: Up to 1 µF capacitance is discharged from 1000 V to
less than 42.4 V in less than 4 secs
Resistance Range
0.1 Ω- 5000 Ω
Test Voltage characteristics
Open circuit Test voltage: 3 V ±0.2 V
Short Circuit Current: 2 mA ±10%
Accuracy: ±1.25% of fsd on a 2.8 in. (71.1mm) arc length:
Safety Voltage Check
Voltage measurement: 0.1 V - 600 V a.c; the meter is RMS
calibrated and average responding
Safety voltage indicator: Indicates the presence of d.c. voltages.
Scaling is not the same as the a.c. meter. True d.c. voltage equals
scale reading divided by 2.22
Accuracy: 2.5% of full scale
Power Supplies
MJ159 and MJ160: Low voltage brushless a.c. generator. Cranking
speed between 130 rpm and 170 rpm
MJ359: Dual operation low voltage brushless a.c. generator or 120
V 50/60 Hz mains (line) supply
MJ459: Six IEC LR6 cells (AA) Battery life: not less than 1300
insulation or Resistance range tests
MJ559: Dual operation 120 V 50/60 Hz mains (line) supply and
rechargeable battery. Six Ni Cad cells (e.g. AA, NEDA 15 NC)
Safety
The instruments meet the requirements for double insulation to
IEC 1010-1(1995), EN 61010 (1995) to installation Category II, 300 V
phase to earth (ground), 600 V installation Category I
Flash Test
6 kV a.c. r.m.s.
MJ TESTERS
Insulation Resistance Testers
100
80
60
40
20
0.01.02 .05 .1 .2 .5 1 2 5 10 20 50 100 200 300 1k 2k ∞
TEST RESISTANCE MΩ
TEST VOLTAGE % (OF RANGE)
100V 250V 500V 1kV
ORDERING INFORMATION
Item Cat. No.
MJ159 Hand-cranked insulation tester 212159
MJ359 120 Va.c./hand-cranked insulation tester.. 212359
MJ459 Battery powered insulation tester 212459
MJ559 120 Va.c. rechargeable insulation tester 212559
MJ160 Low voltage, hand cranked insulation tester
212160
Included Accessories
User guide 6172-113
Test lead set (3 leads, 3 prods, 3 clips) 6220-436
Power cord (where applicable) 25970-002
Test record card (5 supplied) 6172-111
Carrying case 6420-111
Item Cat. No.
Optional Accessories
Test record card (pack of 20) 6111-216
Black test lead with large alligator clip 6220-295
Red test lead with large alligator clip 6220-586
Green test lead with large alligator clip 6220-587
Set of test leads with fused prods (FPK5) -
1000 V a.c. 500 mA fuse 6111-288
Test lead set, 3.6m [12 ft] (1 pair) 210972
Electrodes (for floor testing), 2.25 kg
[5 lb] each (1 pair) 260565
‘A Stitch In Time’ AVTM21-P8B
UK
Archcliffe Road Dover
CT17 9EN England
T+44 (0) 1304 502101
F+44 (0) 1304 207342
UNITED STATES
4271 Bronze Way
Dallas TX 75237-1088 USA
T800 723 2861 (USA only)
T+1 214 333 3201
F +1 214 331 7399
OTHER TECHNICAL SALES OFFICES
Norristown USA, Toronto CANADA,
Mumbai INDIA, Trappes FRANCE,
Sydney AUSTRALIA, Madrid SPAIN
and the Kingdom of BAHRAIN.
ISO STATEMENT
Registered to ISO 9001:2000 Reg no. Q 09290
Registered to ISO 14001 Reg no. EMS 61597
MJ_TESTERS_DS_en_V11
www.megger.com
Megger is a registered trademark
MJTESTERS
Insulation Resistance Testers
Fuses
500 mA (FF) 660 V Ceramic 50 kA HBC 11/4 x 1/4 in.
(32 mm x 6 mm)
7A (F) 440 V Ceramic 10 kA HBC
11/4 x 1/4 in. (32 mm x 6 mm)
100 mA (F) HBC 20 mm x 5 mm (for line protection only)
MJ359 and MJ559 only:
Power connection plug fuse 100 mA 240 V HBC (20 mm x 6 mm)
Mains power cord fused plug (when applicable) 3 A 250 V ceramic
HBC fuse to BS1362 11/4 x 1/4 in. (32 mm x 6 mm)
E.M.C.
In accordance with IEC 61326-1.
Note: These instruments are designed for use in a controlled
electromagnetic environment
Operating Temperature Range
32° to 113°F (0° to 45°C) for battery operated models
14° to 122°F (-10° to 50°C)
Humidity Range
Operating:
70% RH max. at 68°F (20°C)
60% RH max. at 95°F (35°C)
50% RH max. at 105°F (40°C)
Storage: 95% RH max. at 95° F (35°C)
Dimensions
5.1 H x 4.9 W x 7 L in.
(130 H x 125 W x 180 L mm)
Weight
Approximately 1 kg (2,3lb)
Cleaning
Wipe disconnected instrument with a clean cloth dampened with
soapy water or Isopropyl Alcohol (IPA).
