Transformer model meaning Transformer specifications and models Safety operating procedures for transformers
Transformer model meanings Transformer specifications and models
1. There are many specifications and models of transformers, and different specifications have different meanings.
2. Common examples: dry-type transformer
“SCB10-1000KVA/10KV/0.4KV” dry-type transformer means:
S It means that this transformer is a three-phase transformer. If S is replaced by D, it means that this transformer is single-phase.
C means that the (dry-type transformer) windings are resin cast solids.
B means foil winding, if it is R, it means wound winding, if it is L, it means aluminum winding, if it is Z, it means on-load voltage regulation (copper is not marked).
10 represents the design serial number, also called the technical serial number.
1000KVA represents the rated capacity of this transformer (1000 kVA).
10KV means primary rated voltage, 0.4KV means secondary rated voltage.
3. The meaning of common “power transformer” specifications and models
The model of power transformer: usually represents the number of phases, cooling method, voltage regulation method, winding core and other materials symbol, as well as the transformer capacity, rated voltage, and winding connection method.
4 For example: “SFSZ9-31500/110” transformer model meaning
S: three-phase, F: air-cooled, S: three-winding, Z: on-load voltage regulation, 9 :Design number 9 type.
31500: Rated capacity is 31500kVA
110: Primary side rated voltage 110kV
Safe operating procedures for transformers
1. Before installing large oil-immersed transformers, safety construction measures must be prepared according to the installation instructions.
2. The nitrogen-filled transformer has not fully discharged nitrogen (its gas oxygen density is >18%), and workers are strictly prohibited from entering. When filling the nitrogen-filled transformer with oil, no one is allowed to stay at the exhaust hole.
3 During the oil draining and oil filtering process of large oil-immersed transformers, the shell and windings on each side must be reliably grounded.
4. When inspecting the transformer hanging core, the core must not be stacked on the oil tank, but should be placed on a clean support prepared in advance. No work should be done on the core before the lifting rope has been relaxed.
5. When inspecting the transformer hanging cover, remove the outer cover and place it on a clean skid before starting the core inspection. When hanging the cover, special personnel should be placed around to monitor it. It is strictly forbidden for the outer cover to touch any part of the core.
6. The transformer must be raised and lowered smoothly when lifting the core or hood.
7.When conducting internal inspections of transformers, ventilation and lighting must be good, and special personnel must be assigned to monitor them; workers should wear buttonless, pocket-less work clothes, oil-resistant and non-slip boots, and tools brought in must be tied, registered, and counted, and tools and miscellaneous items must be strictly guarded against. Things are left inside the vessel.
8. The cover flange bolts must be tightened symmetrically and evenly.
9 When inspecting the core of a large transformer, scaffolding should be set up, and climbing up and down the lead wooden frame is strictly prohibited.
10. The oil storage and oil processing site must be equipped with sufficient and reliable fire-fighting equipment, and a clear fire-fighting responsibility system must be established. The site should be flat and clean, and there must be no fire or flammable and explosive items within 10m.
11. When the transformer accessories are defective and need to be welded, the residual oil should be drained, the surface oil stain should be removed, and the welding process should be carried out after transporting it to a safe place.
12. When the transformer lead welding is poor and needs to be repaired on site, thermal insulation and isolation measures should be taken.
13. Repair welding is allowed for minor leaks in oil-filled transformers.
14. There should be an open hole on the top of the transformer.
15. The welding part must be below the oil level.
16. Fire welding is strictly prohibited and intermittent electric welding should be used.
17. The oil stains around the solder joints should be cleaned up.
18. Proper safety and fire prevention measures should be taken, and safety technical explanations should be given to participants.
19. Safety technical measures and necessary management systems should be formulated before drying the transformer.
20. The power supply and wires used in the drying transformer should be calculated, and there should be an overload automatic cut-off device and an overheating alarm device in the circuit.
21. When drying the transformer, a thermometer should be installed on the core, winding or upper oil surface according to the drying method, but the use of mercury thermometers is strictly prohibited.
22. The drying transformer should have personnel on duty. Personnel on duty should frequently inspect the temperature of various parts for overheating and abnormal conditions, and keep records. Personnel on duty are not allowed to leave the drying site without permission.
23. When using short circuit drying, the short circuit should be firmly connected. When using eddy current drying, insulated wires should be used; when using bare wires, a low-voltage power supply must be used, and reliable insulation measures should be taken.
24. When using an external power supply for drying, the transformer shell should be grounded.
25. When using vacuum hot oil circulation for drying, the shell and windings on each side must be reliably grounded.
26. No flammable items should be placed on the drying transformer site, and sufficient fire-fighting equipment should be prepared.
Other notes
1. During the installation of power transformers, an experienced person in charge of equipment installation should be on-site to direct.
2. Non-construction personnel are not allowed to enter the work area.
3. During night construction, the working area should have good lighting.
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