2.4 Testing and Results
The testing levels of temperature are determined
according to the pre-test results for operating time with
changing the temperature and closing phase. The pre-test
results are given in Figure 5. The temperature is possible to
control in the test but the closing phase is somehow
difficult so that only the temperature is selected as an
acceleration stress and the testing voltage and rate are fixed.
The rate is an accelerated factor of time and the voltage is
an accelerated factor of shock. In this work, acceleration
factors for the temperature and the voltage levels are
obtained.
The results of pre-tests in the range of 40 ℃ and 80 ℃
indicate that the operating time is approximately the same
along with closing phase.
In Fig. 5, A (120 ℃/30 degrees) is the area where the
value of the coil resistance is increasing so that the