Power Transformer Loading

Presumably forever, but there are some real-life limits on duration such that nothing really lasts quite that long.

Until it fails.

Maybe you should try asking people who make them.

Or, until it falls off the truck.

Now, that's just being too cute.

14 hrs per day....

From your previous questions it sounds like you work at a thermal power plant. It also sounds like you really are not qualified to do so.

I am not going to offer advice to someone I think is doing something very dangerous and outside what they are qualified to do, ESPECIALLY if they got themselves responsible for the management or maintenance of a thermal power plant, which appears to be the case here.

Hire a competent Engineer. A multi million dollar, multi-megawatt power plant is not a toy!

ask manufacturer. consider continuous continuous and cycling loads and harmonics

Indefinitely. This question may be answered by transformer manufacturers over the telephone!

Read what it says on the rating plate on the side of the transfo. It should state the standard to which it was made & ratings without & with pump. Better still, refer to the documentation with the transfo and the standard to which it was designed.

Normally, ratings are continuous for certain ambient and temperature rise conditions.

I am having two 45MVA Unit transformers & one 50MVA station transformer.My total load is approximately 45MVA. I would like to know how much spare capacity i have. That's why I am asking how long a oil forced transformer can be fully loaded?

Looks like 45 (or even 95) MVA spare capacity. Jeez, you must be fully loaded with money. Or Johnnie Walker.

A single line diagram would help.... my impression is that you have 2 "45MVA" generators & One common station transfo 50 MVA. Your load on the 50 MVA transfo would be 45 MVA?

Typically each genset would run half the hours, but the 50 MVA would always be loaded.

So the genset transfos use up their life at half the rate of the 50 MVA.

A transfo fully loaded to its standard will last 10s of years ON AVERAGE.

A "rule of thumb" is that an extra 8 Celsius insulation temperature will halve its life.

So the extra 5 MVA of the 50MVA may be so that its service life can be expected to be similar to the "half-timer" generator transfos.

Also, if this kit is not new, pushing the ratings could be disastrous.

CR4 posters will not wish to give you bad advise because of lack of knowledge of the circumstances.

Based on your previous posts this is a theoretical question (and not homework) right, not a real thermal power plant you are personally responsible for? Your language implies that it is the latter, but this could just be a language barrier confusion on our part.

The answer to this question will help us determine if you are just trying to improve your knowledge of a subject or if you are doing something.........else.

The way you have posted it REALLY looks like you are responsible for operating a thermal power plant but are not qualified to do so. To say this is unsafe and illegal is somewhat of an understatement.

It's India. That don't matter.

Although some countries may be more lax with their legal and safety standards (and I am NOT mentioning any names here) it still matters regardless of where you are in the world.

A disaster resulting in a loss of income or life is a very effective equaliser.

My emoticon inserter doesn't work, so it's hard to convey satire/parody/irony.

Perhaps the best answer to the OP is, longer than I can!

Mine's been broken for a while (also why I don't post pictures anymore). Try right click over the top and copy paste, that works for me.

Alternatively, go old school ;)