Answer Posted / murugan
Large transformers for indoor use must either be of the dry type, that is, containing no liquid, or use a less-flammable liquid.
Well into the 1970s, polychlorinated biphenyls (PCB)s were often used as a dielectric fluid since they are not flammable. They are toxic, and under incomplete combustion, can form highly toxic products such as furan. Starting in the early 1970s, concerns about the toxicity of PCBs have led to their banning in many countries.
Today, non-toxic, stable silicon-based or fluorinated hydrocarbons are used, where the added expense of a fire-resistant liquid offsets additional building cost for a transformer vault. Combustion-resistant vegetable oil-based dielectric coolants and synthetic pentaerythritol tetra fatty acid (C7, C8) esters are also becoming increasingly common as alternatives to naphthenic mineral oil. Esters are non-toxic to aquatic life, readily biodegradable, and have a lower volatility and a higher flash points than mineral oil.
| Is This Answer Correct ? | 1 Yes | 0 No |
Post New Answer View All Answers
what are the maximum available current, voltage ratings and switching speeds of the power electronic devices thyristor, power mosfet, igbt, and mct?
What does quality factor depend on in resonance?
Difference between low impedance and high impedance Restricted Earth Fault
HOW DO YOU CAN CHECK A 15KV DIODE, WHETHER IT IS OK OR NOT?
why transformer ratings in kva? & DG ratings in kva? & Motor ratings in kw/HP?
what a function diesel generetaor turbo charger & turbo charger is more heated explain reason ?
what is meant by loss of field in a DC motor? how a universal motor works?
How to calculate fault level of 11 KV system
Why the efficiency of a three-phase induction is the motor is less than that of a three-phase transformer?
how to calculate current carring capacity of cable and cable selection? 1) copper flexible cable 2) copper armoured cable 3) Aluminium cable
how to calculate fault level?
What are merits & De-merits of State-Space Method? What is series programming, parallel programming, general programming & direct programming ? And, difference between these programmings Techniques ?
whatis the commertial spec. of distribution boards ?
Why is the frequency not changed during transformation of electrical energy in a transformer?
which fault is severe and why?between lll fault and lllg fault which fault is severe and y?