Contents
What is S in a transformer?
S = kVA rating of the transformer. U20 = phase-to-phase secondary no-load voltage. In = rated current of the transformer. Isc = short-circuit current in amps. Usc = short-circuit impedance voltage of the transformer in %.
What do the dots on a transformer mean?
polarity
Transformer Conventions A pair of dots indicates polarity. The similar placement of these dots next to the top ends of the primary and secondary windings tells us that whatever instantaneous voltage polarity is seen across the primary winding will be the same as that across the secondary winding.
What is the power factor of transformer?
As the load on a transformer increases, the reactance decreases, and the power factor increases. At full load, the power factor approaches 1. Loads with a low power factor draw considerably more current than loads with a power factor near unity.
What do the symbols mean on lighting transformers?
Essentially the symbols represent standards and indicate the capabilities of the transformer. Here are a number of covers of both lighting transformers and electronic transformers. Looking at the pictures it was apparent they had a lot of product information printed onto them.
Which is the HV side of a transformer?
The HV lead H 1 is brought out on the right side when facing the HV side of the trans- former case. The remaining HV side leads H 2 and H 3 are brought out and numbered in sequence from right to left. The low-voltage side lead, X 1 is brought out on the left side facing the low side of the transformer case.
Where are the low voltage leads on a transformer?
The low-voltage side lead, X 1 is brought out on the left side facing the low side of the transformer case. The remaining low-voltage side leads, X 2 and X 3, are numbered in sequence from left to right. This is shown in Figure 5.12.
What does the VDE mark on a Transformers mean?
The VDE mark denotes conformity with the VDE regulations or European or internationally harmonised standards and confirms the compliance with the safety requirements of the directive. The VDE mark stands for the safety of the product in terms of electrical, mechanical, thermal, toxic, radiological and other hazards.