Operation & Maintanance Manual

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OPERATION AND

MAINTENANCE

MANUAL FOR

H.V.BREAKDOWN TESTER

0-75KV 75mA D.C

CUSTOMER: - BHARAT HEAVY ELECTRICALS LTD. BHOPAL

CUSTOMER P.O. NO.: - 1105469 DATED: 07.12.2010

Designed and Manufactured by:

TESLA ELECTRICAL INDUSTRIESAncillary to Bharat Heavy Electrical Ltd. Bhopal,

41-B, BHEL Ancillary Industries Estate,

Habibganj, Bhopal (M.P) INDIA

Phone No. +91-755-2588617 (O)


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H.V. BREAKDOWN TESTER

75KV 75mA D.C

THE BREAKDOWN TESTER IS FOR TESTING THE INSULATIONSTRENGTH OF LARGE ELECTRICAL MACHINES, COMPONENETS, CABLES

etc.

TECHNICAL DETAILS:

IT CONSISTS OF TWO MAIN UNITS:1. THE CONTROL AND METERING PANEL (CMP).

2. THE TRANSFORMER RECTIFIER UNIT (TRU).

Operating voltage: 230V, 50Hz, A.C.

Output voltage: 0 to 37.5KV and 0 to 75KV D.C Continuously Variable.

The set is HIGH RESOLUTION TYPE hence can be used independently for two

ranges of 37.5KV & 75KV. This is made possible by two windings, which changes the

complete range of HV Transformer.

CAPACITY :

75mA max. On H.V Side.2.812KW in 0 to 37.5KV5.625KW in 0 to 75KV Range.

DUTY CYCLE: 50%

1. Control & Metering Panel

This consists of main input Fuses, MCB, Contactor fuses, indicating

lamps, push buttons, timer, tripping circuits, meters etc.

All these equipments are housed in a robust cabinet with adequateventilation. Bi-directional wheels are provided for mobility of control panel. The cabinet

is of min 1.6 mm sheet, sand blasted applied with 2 coats of red oxide and painted in

Opline green glossy synthetic enamel. All the wiring is carried out using reputed make

cables of appropriate cross-sectional area.

All the control wiring is carried out using 1mm sq. multistrand copper

wire of reputed make.

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The ends of cables are terminated with crimped lugs and ferrule makers as

per the drawing numbers. The cables are terminated on suitable terminal blocks. Glandplates are provided at the bottom or rear side for the cable entry.

2. High Voltage Transformer

This is a Step-Up Transformer specifically designed for H.V. Breakdown

applications with HIGHELY GRADED INSULATION on secondary side of thewindings.

The primary winding is in two sections so as to provide high-resolution

system. All the Windings are of electrolytic grade copper conductor or appropriate cross

sectional area so as to keep the temperature rise within limits.

Since the equipment is subjected to frequent short circuits, hence the

design is such that it gives trouble free service.

The Multi-Stepped Core used is of high grade CRGO steel of M4, M3 or

M2 H grade material only.

The transformer is Oil-Cooled Type.

3. Rectifier: It is rated for the required D.C. voltage with several diodes in series.Each diode will have surge protection. The rectifier will be single-phase full wave bridge.

It will be oil-cooled type housed in the tank with H.V. Transformer.

4. H.T. Terminal Cable Stand: A Stand is provided for H.V. Terminal end of the HighVoltage Cable. On the top side it is insulated from earth for a distance of approx 450mm.

H.T. Cable with spherical termination should be kept near the Job under Test, and the

sphere side can be connected to the Job with Fuse wire.

The earth to the Job should be connected by Earth Clip provided with the H.T.Cable.

For transportation purpose the cable stand is folding type.

4.1 Assembly: The H.T. Cable Stand consist of the following:

1. The Base 2. M.S. Pipe 3. Insulated (Epoxy glass) Cable support.

1. The Base is a tripod with a bush at the centre to accommodate bottom side of MS

Pipe.

2. The MS. Pipe has two positions for M6 size bolt, one at the centre, and other at

125mm from the Top side. The other side is bottom side, and is to be inserted on the

bush of the base stand.

3. Insulated Cable support:- This is a Epoxy glass pipe with slots at right angles at the topfor holding the H.T. Cable at Spherical Terminal End.

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The base, pipe and insulated cable support are mounted separately on

H.V. Transformer Tank.

Refer Drg. No. TEI/HVDC/75-75 Page 3 of 3

1. For assembling, keep the base on ground.

2. Insert bottom of MS Pipe on the bush of the base.

3. Take out Insulated Cable Support from MS Pipe.

4. Take out M6 bolt from position2 and insert in position 1 on MS Pipe.

5. Insert the Pipe of Insulated Cable Support to the MS Pipe.

The Stand is ready for Use.

Now place the stand near to the Job under test and connect ball side terminal toH.T. Side of Job with fuse wire, and earth side with clip.

5. SPECIAL FEATURS

a. HIGH RESOLUTION DESIGN: This enables to use the setindependently as 0 to 37.5KV or 0 to 75KV, hence readability is very fine.

b. LEAKAGE CURRENT SETTING: The leakage current can be from20% to 100% of the maximum value, through a potentiometer provided on

the front of the panel. Hence no disconnecting link is required.

The tripping Ckt is a watchdog type protection and HV set can be put to

operation only when this circuit is healthy.

c. VERY SAFE IN OPERATION: as current setting is possible throughsolidly grounded resistor and no link changing is required on H.T. side of

transformer rectifier unit.

d. THE HIGH VOLTAGE TRANSFORMER: is a single unit andhence is highly efficient with minimum impedance, better power factor

and minimum partial discharge.

e. HIGH ACCURACY: with specially designed highly graded winding

so as to reduce the capacitance effect and eliminate the use of voltagedivider for normal test on insulating materials.

f. All the switchgear items are of reputed make such as L&T,

Siemens, BCH, Kaycee, English Electric, Elmex, Technoplast

make only. The meters are of MECO or AE make only. THE SET CANBE MAINTAINED EASILY BY PROCURING THE ITEMS

LOCALLY.

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g. STAINLESS STEEL EARTHING terminals are provided on boththe sides of the control panel and HV Transformer rectifier units.

h. Kilovolt meter reads the proportionate voltage from Potential Divider,

resulting in high accuracy.

INSTALLATION:

CHECK FOR ANY PHYSICAL DAMAGE TO THE CONTROL PANEL AND

TRANSFORMER RECTIFIER UNIT (TRU).

CHECK FOR ANY OIL LEAKAGE AND ENSURE THAT OIL LEVEL IS

MINIMUM TO THE HALF MARK. EARTH THE CONTROL PANEL AND TRU INDEPENDENTLY AND THEN

INTERCONNECT EACH OTHER WITH MINIMUM 6sq.mm FLEXIBLE

COPPER CONDUCTOR.

CONNECT THE INPUT TERMINALS TO 1PH 230V SUPPLY WITH MIN. 1.5sq.mm COPPER WIRE.

CONNECT WIRE 15 AND 16 TO H4 AND H1 RESPECTIVELY.

CONNECT THE WIRE 17 AND 18 TO THE RESPECTIVELY TERMINALST17 AND T18 AND WIRE D1 AND D2 TO THE TERMINALS D1 AND D2.

OPERATION:

SWITCH ON THE MCB.

o MAINS ON INDICATION WILL BE AVAILABLE AND VARIAC

WILL MOVE TO ZERO AUTOMATICALLY AND VARIAC ZEROINDICATION WILL BE AVAILABLE.

PRESS THE TEST ON PUSH BUTTON.

o TEST ON INDICATION WILL BE AVAILABLE AND DANGER

LIGHT WILL FLASH.

INCREASE THE VOLTAGE WITH TOGGLE SWITCH TS2.

DO NOT INCREASE THE VOLTAGE FURTHER IF ANY OF THE NEON

LAMP ON THE PANEL GLOWS.

(SWITCH OFF THE SET AND CONTACT MANUFACTURER)

WHEN REQUIRED TEST VOLTAGE IS ACHIEVED, SWITCH ON THE

TIMER.

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o AFTER THE PRESET TIME, THE BUZZER WILL SOUND.

DECREASE THE VOLTAGE TO ZERO WITH THE TOGGLE SWITCH.

o IN CASE THE SPECIMEN UNDER TEST FAILS THE SET WILL

TRIP AND THE VARIAC WILL COME TO ZERO POSITIONAUTOMATICALLY.

REPEAT THE ABOVE SEQUENCE FOR SECOND TEST.

MAINTENANCE:

1. CHECK THE OIL LEVEL IN THE TRANSFORMER TANK REGULARLY;

FILTER THE OIL IF THE BREAKDOWN VALUE IS LESS THAN 75KV.

2. CHANGE SILICAGEL IN THE BREATHER IF THE COLOR IS CHANGED

TO PINK.

3. ALWAYS USE HRC FUSE CATRIDGES.

4. KEEP THE TESTER CLEAN AND IN DRY PLACE.

5. CHECK FOR PROPER EARTHING REGULARLY.

6. IF ANY OF THE NEON LAMP ON THE TANK GLOW, DO NOT USE THE

TESTER AND CONTACT TO MANUFACTURER IMMEDIATELY.

CAUTION:

DO NOT INCREASE THE VOLTAGE FURTHER IF ANY OF THE NEONLAMP ON THE TRU GLOWS.

(SWITCH OFF THE SET AND CONTACT MANUFACTURER)

WHEN REQUIRED TEST VOLTAGE IS ACHIEVED, SWITCH ON THETIMER.

o AFTER THE PRESET TIME, THE BUZZER WILL SOUND.

o DECREASE THE VOLTAGE TO ZERO WITH THE TOGGLE

SWITCH.o IN CASE THE SPECIMEN UNDER TEST FAILS THE SET WILL

TRIP AND THE VARIAC WILL COME TO ZERO POSITION

AUTOMATICALLY.

DANGER HIGH VOLTAGE

DO NOT OPERATE WITHOUT PROPER EARTHING

DO NOT OPERATE THE SET IF ANY OF THE NEON LAMP GLOWS.

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PLEASE READ THE INSTRUCTION CAREFULLY BEFORE USE

ONLY TRAINED PERSONALS TO OPERATE THE SET

PRECAUTIONS:

EARTH THE CONTROL PANEL AND THE H.V. TRANSFORMER UNIT

INDEPENDENTLY AND THEN INTERCONNECT EACH OTHER.

ALWAYS USE MULTI-STRAND FLEXIBLE COPPER CONDUCTOR (OF

CROSS-SECTIONAL AREA 1.5 TIMES OF MAINS INPUT CABLE) FOR

EARTHING.

USE CRIMPING LUGS WITH SOLDERING AT BOTH THE ENDS.

OIL LEVEL SHOULD ALWAYS BE MAINTAINED UP TO THE MINIMUM

IN OIL LEVEL INDICATOR BEFORE STARTING THE TESTING.

KEEP THE H.V. TRANSFORMER IN DRY PLACE AWAY FROMMOISTURE.

CHECK BDV OF H.V. TRANSFORMER OIL IF THE EQUIPMENT IS KEPT

STORED (UNUSED) FOR MORE THAN 12 WEEKS. (THE BDV OF OIL

SHOULD BE MIN. 60KV).

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Operation & Maintanance Manual