RETURN HOME

Pole and Pad Mounting Fittings

Regular Fittings such as :

  • Base bolts fasteners
  • Dial Thermometer
  • Pressure Indication
  • Buchnolz Relay
  • Silica Gel Breezers
  • Protective Circuitry
  • Bushings
  • Wooden MV Wire Spacers
  • Oils Receptacles
Regular Fittings such as :

  • Base bolts fasteners
  • Microprocessor Based Temperature Controller with a bigger accuracy and readability scale and above all More Reliability
  • No Pressure Indicators Needed due to absence of liquid insulating mediums
  • No Pressure or Buchnolz Relays Needed due to absence of any harmful gas formation and containment
  • No Silica Gel Breezers for the same reasons mentioned above
  • Protective Circuitry
  • Due to the construction of the transformer a safe direct access to the MV & LV leads is attained without the need for Bushings that create extra capacitive loading on the transformer
  • This is an optional fitting, but usually due to the construction of the Cast Resin Transformer, clearances between phases and subsequently wires connecting them to supply/source is inherently considered within the transformer construction and there is therefore no need for extra an Wooden MV Wire Spacers
  • No liquid insulating medium, therefore no leakage and no receptacles to contain this leakage are needed

Advantage in the Network

Oil Type Transformers Behaviour in the network is :

  • Higher overall losses with increasing load and thus decreasing efficiency and more demand from the sending end power plants
  • Due to safety issues transformers location has to be specially studied thus more & longer cables are needed to get the power out of the transformers and to the required load, thus creating more losses in the cables and lowering further the efficiency of the system
  • Low overload capability, thus requiring constant upgrading of the available transformers and thus creating a constant stress on the network design and expansion
  • Regular Off-Line Maintenance Procedures puts more stress on various sections of the network and shuts off some other sections temporarily
  • Average short circuit withstand levels, due to internal construction, impedance, … reduces overall network resilience to transient errors and thus networks and transformers have to be costly protected and designed
Dry Type Transformers Behaviour in the network is :

  • Lower overall losses with increasing load and thus better efficiency and less demand from the sending end power plants
  • No safety issues and concerns thus locating the transformer is of no concern and it can be placed very close to load centres thus reducing even further cable length and size creating less transmission losses and increasing the efficiency of the overall system
  • High overload capability, thus requiring a less frequent transformer upgrading and a more stable network design for a longer period of time with less frequent expansions
  • Due to the construction of the cast resin transformer maintenance is limited to a lightning check and often needs no intervention thus avoiding putting the transformer off-line and avoiding straining sections of the network
  • Excellent short circuit withstand levels due to the solid coil casting, construction, impedance, … increases overall network resilience to transient errors, thus increasing network safety and reducing very costly and redundant designs

Safety Concerns

Oil Type Transformers Behaviour in the network is :

  • Due to the nature of the insulating oil (ignition points of 300 oC) fire risks are imminent and no fire retardant properties are obtained
  • Even with the most sophisticated pressure relief valves, gas build up in the insulating oil causes dramatic failure over time, leading to very dangerous meltdowns of the oil insulated transformers
  • Even with the most sophisticated Buchnolz relays and Pressure Relief valves a split millisecond failure of these mechanical devices in clearing a suddenly built up pressure (due to a transient error) will lead to catastrophic explosions
  • High current densities (up to 3.8 amps/mm2) reduces the transformer ability to withstand prolonged overloads by reducing its thermal constant and thus leading to more risks of overheating and oil ignition.
  • Regular gas dissipation are a major safety concern for the ozone layer that protects all forms of life from the UV sun rays
  • Oil leakage are a major environmental concern, because this insulating medium is not bio-degradable at all
  • PCB and PCE contents in the insulating oil has been proven by the WHO to be cancerous materials
  • High noise levels and sound emissions due to the construction of the transformer, thus adding to the noise pollution

    OIL TRANSFORMER
Dry Type Transformers Behaviour in the network is :

  • Due to the nature of the insulating epoxy resin, excellent fire properties are attained (ignition points above 1000 oC) and the epoxy resin fillers (such as the Al(OH)3 and the Silica will work as fire extinguisher and retardant elements. (Claims supported by F1 fire certification tests)
  • A vacuum cast solid insulation system (partial discharge levels less the 10 pC) is a guarantee that no gas build up will occur through out the life of the transformer and thus will avoiding catastrophic meltdown even if the transformer fails
  • No liquid insulation system, means no gas and therefore pressure build up, therefore avoiding all dramatic explosions even under fault conditions and thus avoiding special safety precautions
  • Low current densities (up to 2.2 amps/mm2) increases the transformer ability to withstand prolonged overloads by increasing the thermal constant and thus reducing the risks of overheating and failure
  • No ozone layer harmful gas dissipation are emitted by the insulation system and thus theses transformers are conforming to the recommendation of the earth summit in Kyoto
  • No oil leakage and therefore no concerns about creating slumps and no concerns about polluting the surroundings
  • Due to its passive components and elements the solid insulating system has been universally proven to be free of any cancerous material for its users, thus no health hazards are present
  • Comparatively less noise and sound levels due to the construction of the transformer thus helping to control noise pollution