Temperatue rise

[Mahadev]

I am passing Xamps thru a Ylenth of conductor for time t sec. can anybody suggest me how to calculate temperarure rise in the conductor after time tsec in a conductor

[Goalie_Ca]

Sorry if i'm wasting your time but you can determine the resistivity of the conductor based on those factors.

Normally what i have seen are graphs of various materials vs power dissipation.

Here's info on a thermistor in the meanwhile. http://en.wikipedia.org/wiki/Thermistor

[lala_alak]

If you know the resistivity of the conductor,alongwith the cross sectional area,you can find the resistance as (resistivity)*length/area,then the total energy dissipated is (current)squared * resistance.

does that help???

[anggoro_nuswantoro]

If you know the resistivity of the conductor,alongwith the cross sectional area,you can find the resistance as (resistivity)*length/area,then the total energy dissipated is (current)squared * resistance.

does that help???

In addition, by knowing the heat capacity of the conductor we can calculate the temperature rise of the conductor from the dissipated power.

aaNg

[Integral]

Realistically temperature can only be calculated in ideal and over simplified situations. There are many factors which effect the final temperature so it is very difficult to consider them all. A very large factor in the temperature of any object is the the temperature of the surroundings and the proximity of other objects. You can calculate accurately total energy loss or gain, but that does not automatically get you temperature.

The best way to find the temperature of a system is to measure it.

[Mahadev]

If you know the resistivity of the conductor,alongwith the cross sectional area,you can find the resistance as (resistivity)*length/area,then the total energy dissipated is (current)squared * resistance.

does that help???


Sorry,
this gives only power loss. how you can calculate a temperature rise after some time t?
Mahadev

[anggoro_nuswantoro]

Realistically temperature can only be calculated in ideal and over simplified situations. There are many factors which effect the final temperature so it is very difficult to consider them all. A very large factor in the temperature of any object is the the temperature of the surroundings and the proximity of other objects. You can calculate accurately total energy loss or gain, but that does not automatically get you temperature.

The best way to find the temperature of a system is to measure it.

But ... engineering works by simplifying situation. Otherwise, we will never arrive anywhere :-)

[Mahadev]

Actually i am designing a new trip coil for MCB so i want to know the temperature rise.
thank you

[anggoro_nuswantoro]

I think the simplification can be used as a first/preliminary estimation.

We can calculate the estimated dissipated heat, then we can find the temperature rise if we know the heat capacity of conductor.

That's the estimation.

To refine the result, used experiment :-)

aaNg

[lala_alak]

So once you multiply the power with time,you are left with the total energy,now you'll need the heat capacity of the material,i believe the overall relation is:

mass*specificheat*temperaturerise = total heat exchange.

I guess now you should be able to calculate the rise in temperature.