SECURITY TRANSITION HIGH VOLTAGE on the low side.

ELECTRICAL NETWORKS DIVISION.

In recent years, to ensure safety when working in electrical voltage applied small, especially with regard to work done in high-risk and highly dangerous. As a source of low voltage used batteries, accumulators and transformers.
When using the step-down transformers may be situations when the voltage of the primary circuit will go into the secondary circuit. Such a transition is possible, for example, the breakdown of insulation and the closure of primary and secondary windings. |
Isolation of secondary power consumers included in this network is generally not designed to stress the primary circuit. This raises the possibility of closure on the case and the emergence of a dangerous touch voltage and step. In the breakdown of winding insulation to ground fault occurs through the resistance of grounding the secondary circuit voltage phase to ground is reduced. If you use a four-wire network, the re-grounding the neutral conductor further reducing the voltage in the secondary circuit to ground at the closure of the windings of the transformer. In the three-wire high voltage isolated neutral zero point is connected to a grounding device through punchy fuse. Punching fuse is a two disc electrodes separated by a mica gasket with the holes. When you are in the secondary circuit voltage greater than the nominal air gap breakdown occurs, current circuit is closed through the grounding connection. Phase to ground voltage is lowered.