Page 268 - Water Standards
P. 268
Table 4 2 13-1 Items and provisions of stator installation tests
No Item Provisions Explanation
Both the standby coils
AC voltage test
and self⁃made coils shall
1 of single —
meet the equipment
stator coil
supplier requirements
( 1 ) Insulation
resistance, absorptance or
polarization indices shall
Stator coil in⁃
meet the requirements of
sulation
Article 4 2 8 in this speci⁃ Use a megohm meter with a
2 resistance,
fication; test voltage of above 2500V
absorptance or
(2) Each phase unbal⁃
polarization index
anced insulation resistance
coefficient shall be no larger
than 2
( 1 ) Measure in the cold
state. The temperature difference
Direct current resistance s between coil surface and sur⁃
deviation between coil phases rounding air shall be no larger
and branches shall be no than 3℃;
Stator coil s di⁃
larger than 2% of the (2) When using the voltage
3 rect current re⁃
minimum value among them drop method, the current shall
sistance
when the deviation has been be no larger than 20% of the
adjusted for that caused by rated current;
wire length difference (3) If the test results exceed
the requirements above, the
reasons shall be determined
(1) Test voltage shall be (1) Tests shall be done in
3 times the rated line volt⁃ the cold state;
age; ( 2 ) Test voltage shall be
(2) The leakage current raised step by step. Increase the
Stator coil DC shall not increase with rated voltage by 0 5 times in
voltage test and time; each step and hold for 1 min.
4
the leakage cur⁃ ( 3) Under the required Read the leakage current in each
rent test voltage, the difference step;
between each phase s (3) If the results cannot meet
leakage current shall be no the requirements above,
larger than 50% of the min⁃ problems shall be found out
imum value and resolved
2 6 1