When the KS11 mining transformer runs normally, the iron core must have a reliable grounding. If there is no grounding, the suspension voltage of the iron core to the ground will cause the core to ground intermittent breakdown discharge, and the iron core will be grounded after grounding, eliminating the possibility of forming the iron core suspension potential. But when the iron core appears more than two points to ground, the uneven potential between the iron cores will form a circulation between the ground points, and lead to multipoint grounding heating failure of the iron core.
The core grounding fault of the KS11 mining transformer will cause the local overheating of the iron core. In severe cases, the local temperature rise of the iron core will increase, and the light gas operation will even lead to tripping of heavy gas action. The local iron core of the fused iron forms a short circuit fault between the iron chips, which causes the iron loss to become larger, and seriously affects the performance and normal operation of the KS11 mining transformer, so that the iron core silicon steel sheet must be replaced. Therefore, KS11 mining transformer does not allow multipoint grounding, only one point, and only a little grounding.
After the completion of the installation of dry-type transformers, the Ji'nan transformer factory should also carry out the inspection of the specified items to ensure that the transformer is installed properly and can operate normally. The inspection items before the <0> run are mainly:
(1) check all fasteners, whether the connectors are loose and re tightened;
(2) check wire series is connected according to the requirements of a / Y11 degrees or Y/Y12 degrees, tap gear connecting piece is fixed on the requirements of gear;
(3) check if there are any foreign objects or tools left during the installation;
(4) check whether the fan, temperature control device and other auxiliary devices can work properly;
(5) check whether the housing and the iron core assembly are permanently grounded