Tom.Margillo
Member
I was asked yesterday about percentage of power loss on a transformer due to heat. Who knows the answer, and where do I find it? 
Power loss due to heat.
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I was asked yesterday about percentage of power loss on a transformer due to heat. Who knows the answer, and where do I find it? 
physis
Senior Member
Re: Power loss due to heat.
I'm gonna make a guess.
Unless the transformer's overloaded, I don't think the resistance added by heating in the coils will have much effect on the secondary current.
I should look up what happens but someone else 'll probably come along who already knows and I wont have to.
I'm gonna make a guess.
Unless the transformer's overloaded, I don't think the resistance added by heating in the coils will have much effect on the secondary current.
I should look up what happens but someone else 'll probably come along who already knows and I wont have to.
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- PE (Retired) - Power Systems
Re: Power loss due to heat.
Effectively all transformer losses are heat.
The first type of losses are from magnetizing the steel core of the transformer and are often refered to as "core losses". This loss is present 24 hours a day so it is the target for the new energy efficient NEMA TP-1 designs.
The second type is the losses caused by the current flow in the winding conductors, these are often called "copper losses" even though most transformers use aluminum windings. This loss is inversely proportional to the loading of the transformer. A lightly loaded transformer has very low conductor loss. These losses can be minimized by increasing the size of the windings which in effect just "derates" the transformer.
A standard 75KVA three phase 150C rise transformer might have the losses as: core = .6%, conductor = 3.6%, total = 4.2%.
Effectively all transformer losses are heat.
The first type of losses are from magnetizing the steel core of the transformer and are often refered to as "core losses". This loss is present 24 hours a day so it is the target for the new energy efficient NEMA TP-1 designs.
The second type is the losses caused by the current flow in the winding conductors, these are often called "copper losses" even though most transformers use aluminum windings. This loss is inversely proportional to the loading of the transformer. A lightly loaded transformer has very low conductor loss. These losses can be minimized by increasing the size of the windings which in effect just "derates" the transformer.
A standard 75KVA three phase 150C rise transformer might have the losses as: core = .6%, conductor = 3.6%, total = 4.2%.
Re: Power loss due to heat.
You might be able to get as low as 2% losses with an energy star transformer.
Since energy is converted and not destroyed, all the losses have to turn up in some other form of energy (other than electricity). The only other two forms I can think of are heat and vibration (with vibration including the transformer humm). And it takes very little energy to make the humming sound, so almost all the losses wind up as heat.
Steve
[ July 01, 2005, 02:25 PM: Message edited by: steve66 ]
You might be able to get as low as 2% losses with an energy star transformer.
Since energy is converted and not destroyed, all the losses have to turn up in some other form of energy (other than electricity). The only other two forms I can think of are heat and vibration (with vibration including the transformer humm). And it takes very little energy to make the humming sound, so almost all the losses wind up as heat.
Steve
[ July 01, 2005, 02:25 PM: Message edited by: steve66 ]
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