Outdoor Off-load Disconnectors

TYPE OF DESIGNATION:

Rated Voltage : 12-245 KV
Rated Normal Current: upto 3150 Amps
  • Versatile design allowing a wide variety of erection arrangements
  • Simple construction
  • Self cleaning contacts
  • Low operating forces required
  • All steel parts hot-dip galvanized.

DISCONNECTORS:

Energypac manufactures outdoor offload disconnectors of the following types :
  • Pantograph - type EPG
  • Centre Break - type ECB
  • Double Break - type EDB

The disconnector comprise of the following main assemblies:

  • The main current carrying parts called as the hamper assembly.
  • Support insulators mounted between the current carrying parts and base.
  • The bottom base assembly.
  • The operating mechanism box.
  • Inter-stack, inter phase and down operating pipes.
  • Earthing switch and its operating mechanism box wherever called for.
  • Supporting structure mounted between the base and the ground.
Disconnectors can be supplied suitable for horizontal upright mounting on support structure or underhung mounting on substation gantry structure and can be manually operated or motor operated type.

PANTOGRAPH TYPE:

  • Rated voltage from 12 kV to 245 kV
  • Rated current upto 3150 Amps
  • Short time current rating upto 50 kA.

CENTRE BREAK TYPE:

  • Rated voltage from 12 kV to 245 kV.
  • Rated current upto 3150 Amps
  • Short time current rating upto 50kA.

DOUBLE BREAK TYPE:

  • Rated voltage from 12 kV to 245 kV.
  • Rated current upto 3150 Amps
  • Short time current rating upto 50kA.

CONTACTS:

For pantograph type disconnectors, the current transformer contacts consist of the fixed trapeze type contact mounted directly on the top bus and moving contacts made of copper strips mounted on the pantograph moving blade.

PANTOGRAPH DISCONNECTORS:

Type: EPG
  • Very low civil engineering profile.
  • Trapeze contact fixing to suit upper bus arrangement.
  • 4 point contact
  • Available for flexible / rigid busbar layouts.
  • Current transformer through multifinger hinge contacts.
  • Individual pole operation.
  • Structure to suit requirements.

CENTRE BREAK DISCONNECTORS:

Type: ECB
  • Very low operating torque
  • Self wiping contacts
  • Simultaneous operation of 3 poles by single operating mechanism upto 245 kV.
  • Structure to suit requirements.

DOUBLE BREAK DISCONNECTORS:

Type: EDB
  • Turn and twist contacts
  • Vertical/Horizontal terminal take off
  • Totally enclosed actuator assembly
  • Simultaneous operation of 3 poles by single operating mechanism upto 245 kV.
  • Structure to suit requirements.

DESCRIPTION:

The disconnectors consist of separate poles which can be arranged for single pole operation or linked together by operating rods to form 2 or 3 pole units.

BASE FRAME:

For all sizes upto 245 KV, the base frame is of welded design and has minimum four fixing holes.

EARTHING SWITCHES:

Earthing switch can be supplied for mounting as an integral part of the disconnector or for separate mounting as an independent unit operated wither by a manual of motor operating mechanism.

OPERATING MECHANISM:

Currently the following operating mechanisms are offered:
  • Manually operated mechanism
  • Manually operated geared mechanism
  • Motor operated mechanism.

INSULATORS:

A wide range of insulators meeting the requirements of IEC-168 of the stack type are available with various cantilever strengths, creepage distances and insulation levels to meet the customer specifications.

TERMINAL CONNECTORS:

Terminal connectors of rigid or flexible type suitable for horizontal/vertical take offs offered to meet specification.

INTERLOCKS:

Mechanical constructional interlock is provided between the disconnector and earth switch to ensure that the disconnector cannot be closed when the earth switch is closed and vice versa.

INSTALLATION:

Disconnectors are delivered in identifiable parts and assemblies. Assembly of Disconnector and commissioning of the same is to be carried out as per the instructions furnished in the erection and commissioning manual supplied along with the equipment.

MAINTENANCE:

All the bearings provided are sealed for life and need no greasing. All contacts are to be checked and appropriately maintained and cleaned during annual maintenance.

ROUTINE TESTS:

1.RESISTANCE TEST :
  • Operating mechanism
  • Operating universal joints and links
  • Auxiliary contact
  • Inter lock
2.VOLTAGE TEST ON:
  • Auxiliary contact
  • Operating Mechanism
2.FUNCTIONAL TEST ON:
  • Main circuit and attachment
  • Beam and bearing
  • Earthing switch

TYPE TESTS:

Disconnectors offered have been successfully type tested as per IEC 129 and ANSI 37.30 standards at CPRI, India.

STANDARD:

The disconnectors are designed to meet the requirement laid down by IEC 129 and ANSI 37.30.