LT 13 Flashcards
________ material softens when heated and hardens when cools
Thermoplastic
When are rubber compounds used?
Where flexibility and abrasion resistance is needed
What is the purpose of insulation?
To prevent unwanted flow of electrical current, such as ground faults, short circuits or electric shock
What is enamel used for?
Used in Motor Windings, small transformers, and relays
What are some advantages of enamel?
Not too costly, high dialectic strength
What is the dialectic strength of varnished copper?
1000v per mil foot
What are thermoplastics susceptible to?
Cold flow which can deform it under pressure
What is a common thermo Plastic that is used in the trade?
PVC (Polyvinylchloride)
What is T type PVC used for?
Dry locations
What is TW type for?
For wet and dry
What is TWU type suitable for?
For direct burial in the ground
What is the maximum temperature that PVC can be exposed to?
60 degrees
What is XLPE OR X-LINK?
Combines the excellent electrical properties of thermoplastic polyethylene with the thermal properties of a thermosetting material
What minerals are used for insulation ?
Mica and Magnesium Oxide
The colour green is used for the …
Bone conductor
Greyish /white insulation is for the ….
Neutral
What are some qualities of magnesium oxide?
powder with very high resistance when dry
Resistance decreases considerable when wet
Resistance increases when mineral is compressed
