**2. Electrical installation of the induction-melt furnace**

The analyzed coreless induction furnace has 12.5 t capacity of cast-iron; the furnace is supplied from the three-phase medium-voltage network (6 kV) through a transformer in / connection, with step-variable voltage. Load balancing of the three-phase network is currently achieved by a Steinmetz circuit, and the power factor correction is achieved by means of some step-switching capacitor banks (fig.1).

In the electric scheme from fig. 1: Q1 is an indoor three-poles disconnector, type STIm–10– 1250 (10 kV, 1250 A), Q2 is an automatic circuit-breaker OROMAX (6 kV, 2500 A), T is the furnace transformer (2625 kVA; 6/1.2 kV), K1 is a contactor (1600 A), (1) is the Steinmetz circuit used to balance the line currents, (2) is the power factor compensation installation, TC1m, TC2m, TC3m (300/5 A) and TC1, TC2, TC3 (1600/5 A) are current transformers, TT1m (6000/100 V), TT1 (1320/110 V) are voltage transformers, and M is the flexible connection of the induction furnace CI.

Within the study the following physical aspects were taken into account:


As consequence, will be present the influence of the following factors upon the energetic parameters of the installation: furnace charge, furnace supply voltage, load balancing installation and the one of power factor compensation.
