Grouch1980
Senior Member
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- New York, NY
giving this another bump 
. It's my question from post #19.
. It's my question from post #19.
Transformer secondary protection
- Thread starter Grouch1980
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gar
Senior Member
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- Ann Arbor, Michigan
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- EE
221227-0944 EST
Grouch1980:
A rating on a device or system is selected to provide some reasonable lifetime for that product. The rating for the same product will be different for different assumptions ( different environments, and characteristics of the device or system ).
Many products do not have a sharp failure point. An oil filled transformer has a much longer thermal time constant than does a non oil filled unit. And very much longer than a point contact transistor. Also the failure mechanisms may be quite different.
Theory and experimental evidence provide means to make useful criteria for various different products.
.
Grouch1980:
A rating on a device or system is selected to provide some reasonable lifetime for that product. The rating for the same product will be different for different assumptions ( different environments, and characteristics of the device or system ).
Many products do not have a sharp failure point. An oil filled transformer has a much longer thermal time constant than does a non oil filled unit. And very much longer than a point contact transistor. Also the failure mechanisms may be quite different.
Theory and experimental evidence provide means to make useful criteria for various different products.
.
Grouch1980
Senior Member
- Location
- New York, NY
That's the answer for Post #19?
I didn't really read all that link, but I don't believe inrush is ALL DC offset.
There is some, albeit small, asymmetrical current demand whenever the transformer is energized simply because the magnetization of the core is unbalanced.
many other factors also can contribute to the magnitude of currents. Point on wave, residual flux left in the core when switched off, such as in a reclosing condition, and even the transformer core itself.
There is some, albeit small, asymmetrical current demand whenever the transformer is energized simply because the magnetization of the core is unbalanced.
many other factors also can contribute to the magnitude of currents. Point on wave, residual flux left in the core when switched off, such as in a reclosing condition, and even the transformer core itself.
Grouch1980
Senior Member
- Location
- New York, NY
ok got it... thanks guys!
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