Oil Immersed Transformers With Conservator

General Features

The free breathing transformers are equipped with on air cushion under the cover or a conservator to allow the oil to expand, at the temperature variations. As it is not hermetic, the oil is always in contact with the air. Moisture is kept at bay through the use of dehydrating salts contained in special filters (breather). The tank can be in finned or with radiators. This design applies to all powers, but especially from 4000kVA and up. For higher powers and to avoid contact between the oil and air, a rubber separator (rubber bag) or a nitrogen cushion is used.

This type of transformer is equipped with an expansion tank or conservator mounted above the main tank. The expansion of the insulating liquid is compensated inside the conservator by the raising of the oil level. In the conservator the top of the oil is in contact with the air which must remain dry to avoid any oxidation. This is achieved by admitting the outside air in the conservator through a desiccating device containing silica-gel crystals.

Standard Features
  • HV bushings according to DIN 42531 or EN 50180
  • LV bushings according to DIN 42530 or EN 50386
  • Off-Circuit tap changer in 5 positions
  • Tank made of corrugated walls
  • Thermometer pocket
  • Contact thermometer (for transformers ≥ 630 kVA)
  • Buchholz Relay (upon request or ≥ 1000 kVA)
  • Lifting lugs
  • Rating plate
  • Earthing terminals
  • Hole with cap for filling with oil & Drain cock
  • Bi-Directional rollers – 90°
Standard Accessories
  • Earthing Terminals
  • Low Voltage Bushings
  • Off Load Tap Changer
  • Safety Valve
  • Terminal Box
  • Filling Tap
  • Conservator (if not hermetic)
  • Buchholz Relay
  • Lifting Lugs
  • Thermometer pocket
  • Medium Voltage Windings
  • Bi-Directional Rollers
  • Magnetic Core
  • Oil discharge and extraction valve
  • Low Voltage Windings
  • Clamps
  • Oil level indicator (if not hermetic)
  • Medium Voltage Bushings
  • Silica Gel Breather (if not hermetic)
  • Tank with Corrugated Wall
  • Plug-in connectors (upon request)
  • Earthing point on tank
  • Name plate
  • Jacking Pods
Accessories Upon Request
  • DGPT2 or RIS or DMCR (if hermetic)
  • LV Extension Bars
  • Safety Valve with Contacts
  • Winding Temprerature Indicator
  • Cable Box (MV / LV)
  • Oil Level Indicator with Contacts (if not hermetic)
  • PT100 sensors for oil temperature control (PTO)
  • Others (Contact Us)