23-27/5/10

PPU Naka,Kuala Nerang
-There are two type of transformer:power transfomer and distribution transformer
-There are also two type of tap changer:off circuit tap changer and on load tap changer
-Step up transformer increases the voltage while decreasing the current,while a step down transformer decreases the voltage while increasing the current for domestic and commercial distribution.
-Silical gel is a granular,vitreous ,highly porous form of silica made synthetically from sodium silicate.
-silica gel is most commonly encounted in everyday life as beads packed in a vapor-permeable plastics;used as a desciccant to control local humidity in order to avoid spoilage or degradation of some goods.
-Silica gel have very high absorption of moisture(because of poisonous dopants).
-Insulator:-materials-used to reduced the rate of heat transfer or used to reduce heat transfer.Heat energy can be transferred by conduction ,convention,radiation or by actual movement.
:-Flow of heats can be reduced by addressing one or more of these mechanisms and dependent on the physical properties of the material emplyed to do this.
-PILC(Paper insulated lead sheathed)
:Aluminium and copper conductors
:Single core cables:up to 1kv in size up to 1000sqmm
:Three core cables:up to 1 kv in sizes up to 400sqmm
:speacial cables for mining and submarine applications
-XLPE cable(cross-linked polyethe)
:actually is two semiconductors layers on high voltage cable
:one is between actual conductors and XLPE
:other is on outside of XLPE insulation underneath the concentric neutral
-Semi-con used to equalize the electrical stresses over a large area
-Mineral oil:breakdown voltage more than 30kv and moisture level 33ppm(parks/million)
-Type of joint:normal joint,crossbond joint ,termination and linebox