Isolators

Isolators 11 KV up to 400KV

We EREVA TRANSFORMERSANDSWITCHGEARhave been trading wide range of 3 Pole Off Load Isolator Manuals, which finds application in irrigation ,Substations , Industries , Irrigation Projects . These 11KV up to 33KV isolators are compact in design and have low maintenance cost. Our range of technically advanced three poles off load isolators can be operated manually. We also offer these products to the clients at industry leading prices.

Double Break Isolators

Owing to the presence of sound professionals, we are able to trading and supply a diversified range of 33 KV Double Break Isolator (Turn & Twist). We use advance technologies to trading these products and produce world class quality 33 KV Double Break Isolator (Turn & Twist). Our products are widely acclaimed for their precise engineering and maximum efficiency. One can avail these products at economic market leading prices.

  • EREVA TRANSFORMERSANDSWITCHGEAR offers Isolators from 11 kv to 33 kv Lines ,
  • Ranging from 200 amps to 1250 amps .
  • All Isolators are tradingas per IS 9921 & 1818.
  • The Isolators are provided with earth and without earth .
  • We also provide Auxiliary boxes suitable for the Isolators depending upon the customer’s requirement ( 2 no + nc) ( 4 no + 4 nc ) ( 6 no + 6 nc ) .
  • All metal parts / contacts are made of heavily tinned copper alloy.
  • Plated Mild steel Breaking forcing horns , Capable of breaking the magnetizing current complete with horizontal connecting bar GI pipe as down rod levers
  • Coupling and operating handle with Locking arrangements with voltages upto and including 33 kv Line switch yard
  • Original Post Type HT Insulators

Godo Combined

Air break Isolating Switch

EREVA TRANSFORMERS AND SWITCHGEAR tradinggang operated air break off load, disconnecting switch with triple pole. Each pole consists of galvanized steel base, H.T. insulators as per B.S.S./I.S. non-ferrous knife and spring loaded contacts, arcing horns of adequate section to break magnetizing current of the transformers horizontal G.I. pipe 01 adequate length for phase separation, adequate length of G.I. pipes for operation from ground level and operating handle complete in both OFF and ON position. All ferrous parts are hot dipped galvanized and non ferrous parts are heavily tinned to withstand extreme weather. Manufactured in accordance with I.S.S., this product is suitable for horizontal vertical mounting.

S. No Air Break Isolating Switches available in Rocking Tilting Type & Rotating Type
1. 11 KV 200 Amps 3 insulator
2. 11 KV 200 Amps 2 insulator
3. 11 KV 400 Amps 3 insulator
4. 11 KV 630 Amps 3 insulator
5. 11 KV 200 Amps 3 insulator rocking type air break switch with single action make and break (Horizontal Type)
6. 11 KV 400 Amps 3 insulator rocking type air breaks switch with single action make and break “Horizontal Type”
7. 11 KV 200 Amps air break switch with drop out fuse set 12 insulators
8. 11 KV 400 Amps air break switch with dropout fuse set insulators
9. 11 KV switch fuse unit 9 insulator with lighting arrestors.
10 22 KV 200 Amps 3 insulator Vertical type DOUBLE STACK type
11 22 KV 400 Amps 3 insulator Vertical type DOUBLE STACK type
12 22 KV 200 Amps 3 insulator Vertical type DOUBLE STACK type
13 22 KV 400 Amps 3 insulator Vertical type DOUBLE STACK type
14 33 KV 200 Amps 3 insulator Vertical type DOUBLE STACK type
15 33 KV 400 Amps 3 insulator Vertical type DOUBLE STACK type
S. N Spare for Switches available from 11 KV to 33 KV
a. Male contact/moving contact blade
b. Female contact/Fix contact jaw
c. Tinned copper flexible jumper 200A/400A
d. MS jumper carrier
e. Back connector plate
S. N Rotating Type Switch available from 22 KV to 33 KV
1. 200 Amp. horizontal mounting
2. 400 Amp. horizontal mounting
3. 200 Amp./ 1400 Amp with earth switch
Guaranteed Technical Particulars for 11 KV Switch Air Break Type with Post Insulators
S. No. Particulars Technical Particulars
1 trading‘s type / Designation / Installation 11 KV 200, A Tilting type
2a) trading’s name and country of manufacture M/s. EREVA TRANSFORMERSANDSWITCHGEAR
b) Works Address
3 Standard (s) according to which the isolators are manufactured IS 9921 / Part I to V
4 Maximum design voltage at which the isolators can operate 12 KV
5 Rated Frequency 50 Hz.
6 Rated Voltage 12 KV
7 Continuous current rating 200 A
8 Rated short time withstand current
for one second
9 Voltage drop across terminals As per relevant IS
10 Current density at the minimum cross section of :
a) For copper parts ( Amp. /sq . Mm) Less than 2.5
b) For aluminum parts (Amp. Sq/ mm) Less than 1.0
11 Maximum temperature rise of following
current carrying parts when carrying
rated current continuously (deg. C)
over an ambient of 50 deg .
C Instead of 40 deg. C mentioned
in relevant IS
25°C
12 Class (outdoor) Outdoor
13 Insulation levels.
i) impulse withstand voltage (KV peak)
a) Across the isolating distance 85 KV
b) Phase to earth 75 KV
ii) Power Frequency withstand voltage (KV rms)
a) Phase to earth 28 KV
b) Across the isolating distance 32 KV
14 Minimum clearance in air (mm) center
to center between phase to phase
600 mm
15 Minimum distance between insulators As per drawing to be approved
16 Minimum Isolating distance (in open position) 375 mm
17 Design & Construction :
i) Number of insulators Per Pole 3 nos.
ii) Number of breaks Per Pole Single
iii) Type of closing / opening mechanism Vertical
18 Height of contacts 110 mm
19 Cross section and number of fixed contact leafs 2 nos., 38 mm x 3.0 mm thick
20 Cross section of moving blade 32 mm x 5 mm
21 Size and numbers of spring used in fixed contact 4 nos, 16 SWG, 28mm long,
15mm OD & 6 turns
22 All Current carrying copper parts
should be suitable to have
current density less than
2.5 A/ sq. / mm
23 All Current carrying aluminum
parts should be suitable to have
current density less than
1.0 A/ sq/ mm
24 Operating pipe (handle & rod) 25 mm NB, 5.0 meter long med, class
25 Type of bearings Rocking type lever supported on
side plates with self
lubricated nylon rings
26 Base channels 75 mm x 10 mm x 100 mm long
27 Post Insulators
a) Type 11 KV, E-22, IS 2544
b) Name of manufactures Name of manufactures
c) Height of each insulator 245 mm
d) Tensile strength (Kg) 20 KN
e) Compressive strength 40 KN
f) Torsional strength in (Kg m) 340 MN
g) Cantilever strength upright 9 KN
h) Power frequency dry flash over
voltage (KV) rms
As per relevant IS
i) Power frequency we flash over
voltage (KV) rms
As per relevant IS
j) Impulse flash over voltage
(positive wave ) (KV) peak
As per relevant IS
k) Impulse with stand voltage (KV) peak 75
l) Power frequency puncture voltage (KV) rms As per relevant IS
m) Visible discharge voltage level (KV) rms 9
n) Cree page distance 300 mm (min)

Dropout Fuses

Drop Out Fuse (D.O.F) are fuse carriers of fiber glass tube with heavily tinned non ferrous metal parts at both the ends. The brush type phosphorous bronze contacts provide high pressure multi-line connection, wiping and cleaning action. The drop out fuses are widely used for system protection as a secondary back-up against faults or troubles. Installed at high-voltage side, they are able to provide protection in case the trouble is persistent.

S. No Make dropout fuses
16. 11 KV DROPOUT Fuse ‘D type
17. 11 KV DROPOUT Fuse CHANNEL type
18. 22 KV DROPOUT Fuse DOUBLE STACK CHANNEL type
19. 22 KV DROPOUT Fuse DOUBLE STACK “D type
20. 33 KV DROPOUT Fuse DOUBLE STACK CHANNEL type
S. No Make horn gap fuse
21. 11 KV HORN Gap Fuse
22. 22 KV HORN Gap Fuse
23. 33 KV HORN Gap Fuse
S. No Spares for dropout fuses available from 22 KV to 33 KV
1. SRBP tube only
2. Fiber Glass tube only
3. SRBP tube with Metal fitting on both ends
4. Fix Top Contact/L Contact
5. Fix bottom Contact
Guaranteed Technical Particulars for 11 KV Drop out Fuse
S. No Particulars Technical Particulars
1. trading’s type / Designation / Installation ETS
2. trading’s name and country of manufacture EREVA TRANSFORMERSAND​SWITCH GEAR
3. Standard(s) according to which the relevant standard IS 9385/ (Part I/II)
4. Operating Voltage 11KV
5. Rated Voltage 12 KV
6. Continuous current 100 A
7. Type of counting As per drawing to be approved
8. Rated frequency 50 Hz
9. Insulation levels As per relevant IS
10.1 One minute Power frequency withstand
across isolating distance of fuse base
32 KV
10.2 One minute Power frequency withstand
voltage to earth and between poles
28 KV
10.3 Standard Impulse withstand
(1.2/50 micro seconds) to earth and
between poles (peak)
85 KV
10.4 Standard Impulse voltage across isolating
distance of fuse base
75 KV
11. Temperature rise limit (for copper contacts)(deg. C) 25°C
12. Temperature rise for terminals in (deg. C) 40°C
13. Type of fuse / rating Expulsion type, 1.5 A
14. Material of fuse barrel Fibre glass tube 25 mm OD
15. Fuse tube ID 15mm
16. Rated breaking capacity As per relevant IS
17. Fuse base top current carrying part Brass / GM
18. Environmental protection of current carrying part NA
19. Fuse base bottom assembly Brass / GM
20. Fuse carrier top assembly Brass / GM
21. Fuse Carrier bottom assembly As per drawing to be approved
22. Material of spring Phosphor Bronze / SS
23. Material of contacts (incoming) Copper / Glass / Bronze / GM
24. Details of terminal connections (outgoing) Aluminium connector for ACSR Dog conductor
25. Anticorrosive Property (Fe parts) Hot dip Galvanized electroplated
26. Anticorrosive Property (non-ferrous parts) Silver / tin plated
27. Applicable standard IS 9385/ (Part I/II)
33 KV Drop out Fuse
1. Make ETS
2. Drawing No. JB-1007
3. Rated Voltage 33 KV
4. Highest System Voltage 36 KV
5. Rated Current 100/200A
6. Minimum Air Clearance between:
a) Poles 1300mm
b) Live parts and Earth 500mm
7. Mounting position Vertical
8. 33KV Solid Core/22KV post Insulators shall
be fitted & each insulator confirm to
following specifications:
33KV 22KV
i) Make * *
ii) No. of unit per insulator stack 1 2
iii) P.C.D 76mm 76mm
iv) Maximum shed diameter 108mm 101mm
v) Minimum total creepage distance 860mm 430mm
vi) Over all height of the insulator 509mm 254mm
vii) Highest system voltage 36KV 24KV
viii) Tensile strength 5455Kg 3060Kg
ix) Torsional strength 115mkg 70mkg
x) Compressive strength 7000Kg 4600Kg
xi) Flash over voltage (Dry) 145 KV 90 KV
xii) Flash over voltage (Wet) 100KV 60KV
xiii) Dry one minute power frequency
withstand voltage
95KV 80KV
xiv) Wet one minute power frequency withstand voltage 80KV 55KV
xv) Weight of the insulator 14.5Kg 6.1Kg
xvi) 1.2/50 microsecond wave Impulse voltage 200KV 125KV
9. Weight of D.O. Fuse 110 Kg Approx

Discharge Rod and Operating Rod

Centre Break Disconnector

DESIGNATION: HCB
VOLTAGE: 72.5kV to 420kV

CURRENT: Up to 4000A

INTRODUCTION :
The horizontal Centre Break Disconnector is of simple design of two post rotating Centre Break contacts used in outdoor high voltage Sub-station.

CONSTRUCTIONAL FEATURES
BASE ASSEMBLY : The base frame is made out of a fabricated steel structure designed to withstand all the external forces like wind load, dead weight of Insulator & contacts, short circuit force and seismic force etc.  The rotating post is supported by two nos. ball bearing one at top & one at bottom of the bearing housing with adequate distance between them to avoid wobbling of Insulator.
CONTACTS : The main contact is of modern design and has the following salient features

  • Reliable
  • Robust in construction
  • Good electrical & thermal conductivity
  • High long & short time current carrying capacity
  • Low contact resistance due to multi-point contact
  • Suitable for use at high continuous and short time temperature

The jaw and fist type contacts are so designed that the current transfer takes place through multi-point contacts that are equipped with stainless springs, which ensure low contact resistance.
Wiping action carried out during closing & opening of isolator and the design ensures low operational torque and smooth & effective closing of contacts.
The rotating contacts of 420kV disconnectors transfers the current from the terminal stud to the moving blade through silver plated bronze ball contacts that are housed in a bronze housing and pressed against the stud and housing though a stainless steel spring. The rotating contact construction is completely sealed to ensure maintenance free.

DEAD CENTRE MECHANISM :
The 420kV Disconnectors are equipped with the dead centre mechanism that ensures the locking of disconnector in both close and open position in case of extreme external forces such as wind force, short circuit force, seismic force etc.

LINKAGES :
The linkages are provided with left hand thread & right hand thread studs to achieve minute adjustments during alignment of disconnector. All transmission hinge points are provided with roller and socket type bearing with friction free nylon washers to prevent any slackness and consequent lost motion.

DOUBLE BREAK DISCONNECTORS
DESIGNATION: DBR
VOLTAGE: 12kV to 420kV
CURRENT: Up to 4000

INTRODUCTION
The Double Break Disconnector is of simple design of three column centre post rotating used in outdoor high voltage Sub-stations.

CONSTRUCTIONAL FEATURES
BASE ASSEMBLY :
The base frame is made out of a fabricated steel structure designed to withstand all the external forces like wind load, dead weight of Insulator & contacts, short circuit force and seismic force etc..

The centre rotating post is supported by two nos. ball bearing one at top & one at bottom of the bearing housing with adequate distance between them to avoid wobbling of Insulator.

CONTACTS :
The main contact is of modern design and has the following salient features

  • Reliable
  • Robust in construction
  • Good electrical & thermal conductivity
  • High long & short time current carrying capacity
  • Low contact resistance due to multi-point contact
  • Suitable for use at high continuous and short time temperature

The Turn & Twist mechanism with self-wiping, pressure reliving spring-loaded contacts results low contact resistance and ensures proper current transfer in all conditions.

DEAD CENTRE MECHANISM :
The 420kV Disconnectors are equipped with the dead centre mechanism that ensures the locking of disconnector in both close and open position in case of extreme external forces such as wind force, short circuit force, seismic force etc.

LINKAGES :
The linkages are provided with left hand thread & right hand thread studs to achieve minute adjustments during alignment of disconnector. All transmission hinge points are provided with roller and socket type bearing with friction free nylon washers to prevent any slackness and consequent lost motion.

Earthing  Switch

EARTHING SWITCH :
DESIGNATION: ES
VOLTAGE: 12kV to 420kV

The Disconnector may be provided with built on earthing switches on either left hand side or right hand side or on both side as per customer requirement. Maintenance earthing switch can also be provided.

The 420kV-earthing switch has got the following salient features
Self locking
During closing the earth switch makes a double movement

  • a) The earthing blade rotate through 90 so that the blade takes a vertical position i.e. parallel to the insulator  (Refer fig. 7)
  • b) Subsequently the blade makes a vertical upward movement to the end position to ensure proper engagement of contact under pressure

This design results in the locking of the moving blade in the fixed female contact preventing any opening due to short circuit, wind & any seismic forces, even if the operating shaft gets disconnected.

n order to ensure proper current transfer under all conditions, the earthing switch is equipped with high pressure silver plated contacts at the bottom which transfers currents from moving blade to the base frame/earth. Flexible earth connections are not required i.e. a maintenance free Earthing switch in its life time.

A mechanical interlock between the disconnector and the eating switch prevent faulty operations.

Vertical Break Disconnector