Grounding Transformer
The grounding transformer takes NOMEX® aromatic polyamide paper as insulation material, and its insulation class is H which is recognized by UL. This open ventilated dry transformer (OVDT) is an eco-friendly power transformer packed in plywood boxes, and it is safe, flame-retardant, non-toxic, radioresistant and damp proof. In particular, about 700 sets of SJD series earthing transformer are manufactured every year, and this model is highly recommended.
Function
Our grounding transformer is used to create an artificial neutral point for arc suppression coil in cases where the neutral point is not accessible, like power systems with delta or wye connection.
This distribution transformer adopts zigzag connection, and it mainly differs from traditional ones in its structure. More specifically, its coils on each phase are wrapped on two magnetic columns respectively, and this results in very low zero-sequence impedance, usually less than 10Ω. So, for a common transformer that works with arc suppression coil, the capacity of the arc suppression coil shall not exceed 20% of the capacity of transformer, but this value is 90%-100% when applying a zigzag transformer, thus saving a lot of investment.
Aside from arc suppression coil, our polyphase transformer is also compatible with secondary load, so it can work instead of substation transformers. When connected to secondary load, the capacity of primary side of grounding transformer is the sum of arc suppression coil capacity and secondary load capacity.
Technical Data
1. Voltage: 6.3kV, 10kV, 24kV, 35kV
2. Max. capacity: 2000kVA
