246.84 089.862 .672 Cap. 022.812016.876015.348 089.862 .672 Cap.015.348022.812016.876

250.45 090.228 .670 Cap. 023.376017.333015.684 090.228 .670 Cap.015.684023.376017.333

254.11 090.663 .663 Cap. 023.688017.720015.720 090.663 .663 Cap.015.720023.688017.720

254.67 090.846 .663 Cap. 023.856017.838015.840 090.846 .663 Cap.015.840023.856017.838

255.02 091.170 .666 Cap. 023.688017.720015.828 091.170 .666 Cap.015.828023.688017.720

253.64 091.120 .666 Cap. 023.856017.655015.792 091.120 .666 Cap.015.792023.856017.655

253.40 091.713 .665 Cap. 023.820017.806015.876 091.713 .665 Cap.015.876023.820017.806

252.34 091.927 .667 Cap. 024.024017.747015.888 091.927 .667 Cap.015.888024.024017.747

251.83 092.291 .667 Cap. 023.868017.892016.032 092.291 .667 Cap.016.032023.868017.892

251.49 092.581 .667 Cap. 023.916017.768015.936 092.581 .667 Cap.015.936023.916017.768

252.94 093.057 .667 Cap. 024.276017.800015.972 093.057 .667 Cap.015.972024.276017.800

252.79 093.388 .667 Cap. 024.360018.079016.200 093.388 .667 Cap.016.200024.360018.079

252.65 093.781 .668 Cap. 024.324018.117016.284 093.781 .668 Cap.016.284024.324018.117

251.25 094.327 .669 Cap. 024.132018.068016.344 094.327 .669 Cap.016.344024.132018.068

246.84 094.655 .677 Cap. 022.812017.754016.428 094.655 .677 Cap.016.428022.812017.754

250.45 089.862 .680 Cap. 023.376017.693016.560 089.862 .680 Cap.016.560023.376017.693

254.11 090.228 .681 Cap. 023.688017.799015.348 090.228 .681 Cap.015.348023.688017.799

MBINSULATION TESTERMains cum Battery Operated

Type Tested as per BIS11994 : 86

STEP VOLTAGE TESTING

High sensitivity with output stability

POLARIZATION INDEX TESTING

High Charging Current

The MB series Insulation Testers are suitable for high voltage, heavy duty work. The A.C. voltage may be generated either by battery or by a A.C. mains. Tests at voltages between 500 V and 2500 V or 5000 V may be selected as per the selection of models available.

A cross-coils ohmmeter is used to show the insulation resistance readingsdirectly in Megohms. The meter's deflecting circuit is assisted by a CURRENT AMPLIFIER on its upper range, so that a high reading on a widescale can be achieved. The second rotary switch changes the insulationresistance measuring range from inner low (Megohm I) scale to outer high(Megohm II) scale.

The three terminals marked 'L', 'GUARD' and 'E' are mounted on a small panel recessed in to the side of the case, if required the 'GUARD' terminal may be connected to divert any leakage currents to the voltage source rather than allowing them to pass through the ohmmeter, thus, eliminating their effects. Each instrument is assembled in a Teak-wooden case with a laminated top panel and chassis. 5000

4000

3000

2000

1000

2 510 20 50 100 200 500 1000 2000 50000 100000

v

(MW)

Terminal outputs plotted on log scaleMB-5XT

Free AccessoriesMain lead 2m long.

One 3m Earth test lead with shrouded clips.

Operating manual.

One Screened 3m Line test lead with shrouded clips.

Optional Accessories (at extra cost)

8m coaxial test lead with shrouded bull dog clip.

8m screened test lead with shrouded bulldog clip.

GENERAL

APPLICATIONS

8 50

K1

00

K

20

K 10

K 5K 4K 3

K 2K 1K 80

0

60

0

50

0

40

0

30

0

20

0

15

0

10

0

50

40

30

20

10

02

00 5

0

20 15 1

0

5 4 3 2 1

.5 .4

.3

.2

.1

.05

0

MWI

MWII

IS11994-86 5000V/500000 MW

Measuring Scale Model MB- 5XT

*Specifications are subject to change without prior notice

The instrument covers a wide variety of insulation testing requirements and

are especially suited to work on energy network systems. The insulation

testers are ideal for high voltage, heavy duty work, for example, such

applications as are found in the maintenance or servicing of large industrial

electrical installations, generators, distribution networks, switchgear etc.

The instrument can also be employed to make measurements designed to

show the gradual decline that takes place in insulation when this is attacked

by corrosion, dirt, grease, moisture etc. during the operational life of a particular

installation. Such monitoring enables the Maintenance Engineer

to anticipate future performance and to plan ahead.

The instrument can be used to show the improvement in insulation within

motor, generator and transformer windings etc. that results from drying out

procedures, where these have become necessary because of excessive

humidity or because of operation in a moisture laden atmosphere. Regular

STEP VOLTAGE TESTING, at full rating or below when performed over

similar time periods can indicate weakness in insulation. Test voltage ratios

of 1:2, 1:5, and 1:10 are possible with model MB 5XT. DIELECTRIC

ABSORPTION TEST requires the voltage to be applied for

several minutes. The high sensitivity of the instrument enables sensible

reading to be obtained from such POLARIZATION INDEX TESTS.

The terminals voltage characteristics show how this instrument produces

about 90% of its rated maximum voltage at loads as heavy as 30

megohms. Maintaining near rated test voltage at heavy load is essential in

true insulation testing and is a characteristic of this instrument.

SPECIFICATION

Terminal Voltage (Setting at infinity)

_+3% of rated voltage

Short CircuitTerminal Current (max.)

MB-5XT 2.5 mA d.c.

MB-2500 & 5000 2 mA d.c.

Accuracy +_0.76 mm (0.03 in)or as per BIS 11994-86

Power Supply

Dimensions (all models)

350x250x160mm

Weight 11kg (approx.)

AC Mains _+240 V 10%_+50 Hz 5%

Battery Rechargeable Sealed Leadacid Battery 12V7AH withbuilt in Charger

RIL/MK/C-10

RANGES

INSULATIONRANGE

ORDERINGCODE

MB-2500

MB-5000

VOLTAGEOUTPUT

d.c.

2500 V

5000 V

500 V1000 V2500 V5000 V

MB-5XT

0- 500

0- 1000

0- 5000- 200

0- 1000

0- 100

Inner ScaleMegohms

50- 20,000

50- 50,000

10- 50,00020- 100,00050- 250,000

100- 500,000

Outer ScaleMegohms& inf.