No-load test of a direct current motor |
Connection diagram:
The test has the purpose of determining the iron losses and the mechanical
losses.
The reference quantity is the voltage that has to be therefore suitably varied
from a value equal to 1.1 ÷1.2 times the rated voltage until zero.
The quantities to be measured are:
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The quantities to be calculated are:
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From the diagram, in correspondence of the rated voltage value, we obtain respectively the values of Pfe and of Pm.
The significant diagram is:
