Free module. This page is free to read. It does not ask you to sign in. It does not offer a class or a call. Use the edition of each standard named in the contract. Questions: hello@transformerpath.com.
Volume 9 is measurement, capitalisation, and the money in a loss figure. This module separates the two losses a guarantee is actually about. It does not set a capitalisation rate, and it does not call a loss “low” against a regulation you have not opened. Rates and regulatory bands are purchaser’s rules. They are not constants of the transformer.
Two losses, two tests
No-load loss is measured with the secondary open, at rated voltage and rated frequency. It is mostly core loss: hysteresis and eddy loss in the steel, plus a smaller share elsewhere. It is present whenever the unit is energised, whether or not it carries load. Load loss is measured with one winding shorted, at rated current, and it is corrected to a reference temperature because winding resistance changes with temperature. It is mostly the resistive loss in the windings, plus stray loss from leakage flux in the tank, clamps, and the windings themselves. A total loss figure that is not split cannot be capitalised sensibly, because the two losses are bought at different rates and they occur for different hours.
Impedance is measured in the same short-circuit setup as load loss, and it is a guaranteed value of its own. It is not a loss. A unit can meet a loss guarantee and miss an impedance guarantee, or the reverse. The tolerance that applies is the tolerance in the edition the contract names, or a tighter band the contract wrote. This module does not print a percent and call it universal.
Capitalisation is arithmetic the buyer declares
A capitalisation rate turns a kilowatt of loss into a present cost so two offers can be compared. The no-load rate and the load rate are different because a core loss runs all the hours the unit is energised, and a load loss runs with the square of the loading. If the enquiry does not state the rates, the offers cannot be ranked on lifetime cost. They can still be ranked on the guaranteed kilowatts and on price. Inventing a rate after the bids are in is not a evaluation. It is a new enquiry.
- No-load loss: open circuit, rated voltage, rated frequency. It runs whenever the unit is energised.
- Load loss: short circuit, rated current, corrected to the reference temperature. It follows the load.
- Impedance is not a loss. Keep its guarantee and its tolerance separate.
- Capitalisation rates come from the buyer. They are not a property of the steel or the copper.
Worked capitalisation and the tender comparison stay on the paid plan.
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