Potential Consequences Of Not Disconnecting Power During Maintenance For Dry-type Transformers

If the power is not disconnected before on-site inspection and maintenance of dry type distribution transformer, its internal windings, electrical connections and insulation system will still be under electrical load, which will keep the environment energized. dry cell transformer relies on air cooling and solid insulation materials, and its winding and insulation properties are extremely sensitive to temperature and electromagnetic stress. If the 1000 kva dry type transformer is approached or operated while energized, the risk of arcing, electric shock and partial discharge increases significantly, the insulation system may break down or age more rapidly, and this could lead to a wider range of electrical faults.

Live maintenance of 2500 kva dry type transformer may also cause unstable current or grounding faults. Such abnormal conditions in the field environment are usually accompanied by unusual sounds or localized overheating; this unpredictable electrical behavior often leads to equipment damage or even safety accidents. When the coil and connecting parts of component 150kva dry type transformer are in contact while energized, the contact points are highly susceptible to arcing; the heat released by the arc and electromagnetic shock will damage the winding insulation material.