The task of instrument transformers is to transform high currents and voltages proportionally and in-phase into small current or voltage values for measuring or protection purposes. So they are used either to measure and record the transmitted power or to feed protection devices with evaluable signals, which enable the protection device to e.g. trip a switching device depending on the situation. Furthermore, they isolate the connected measuring or protection equipment electrically from live parts of the switchgear.
The active part consists of a magnetic core and mounted thereon multilayer coil. The design can also include some fixing elements.
Nearly 10 years ZTM Ltd. is producing the active part of the gas-insulated voltage transformers. In production, the company is using modern and reliable insulation materials. ZTM Ltd. has high-precision measuring equipment that allows it to set up a transformer in the required accuracy class.
The company’s technologies allow it to produce electromagnetic systems based on a wound or stacked (assembled from laminations) cores. The cross section of the magnetic core is chosen to ensure maximum filling of the "window" while retaining technological efficiency.
The production of a coil is a crucial stage of production. The winding is performed under conditions that exclude contamination of foreign matter (substance, material, etc.) inside the coil. The special heat treatment is used in order to secure the fixing of windings in in the layers of the coil.