- Debes estar registrado para crear debates nuevos.
Kevin White
Kevin White
Respuestas de foro creadas
-
AutorEntradas
-
Kevin WhiteMiembro
To find a transformer’s power rating, you normally read its nameplate, which lists rated primary and secondary voltages, currents and kVA or MVA. If kVA is not given, you can calculate apparent power as S = V × I for single phase or S = ?3 × V × I for three phase, using rated line voltage and current. Always use RMS values. The rating also depends on cooling class and ambient temperature. Some transformers have multiple ratings associated with different cooling modes like ONAN and ONAF.
enero 26, 2026 a las 5:33 pm en respuesta a: Why must a power transformer manufacturer comply with IEC and IEEE standards? #332091Kevin WhiteMiembroIEC and IEEE standards define common technical, safety and testing requirements for power transformers. When a manufacturer complies, utilities know that insulation levels, temperature limits, dielectric strength, short circuit withstand and efficiency meet internationally accepted criteria. This reduces the risk of failures, ensures interoperability with other grid equipment and simplifies specification and procurement. Compliance also supports consistent testing procedures, documentation and naming conventions, which helps engineers design protection schemes and maintenance plans. For large high voltage units, standards compliance is often a strict legal or contractual requirement in tenders.
enero 26, 2026 a las 3:40 am en respuesta a: What types of three phase power transformer connections are used? #331965Kevin WhiteMiembro?-?, Y-Y, ?-Y, Y-?, zig-zag, with standardized vector groups for grounding and phase shift.
enero 26, 2026 a las 1:36 am en respuesta a: What do power voltage transformers do in electrical systems? #331949Kevin WhiteMiembroVoltage transformers (VTs or potential transformers) provide scaled-down, accurate representations of system voltages for metering, protection, and control. They isolate secondary circuits from high voltage while maintaining a precise ratio and phase relationship. This allows protective relays, meters, and automation systems to safely monitor and react to system conditions. In some contexts «power voltage transformers» can also refer to larger step-down units feeding auxiliaries, but usually it denotes instrument transformers dedicated to measurement and protection.
enero 26, 2026 a las 1:21 am en respuesta a: What determines power transformer voltage ratings? #331947Kevin WhiteMiembroVoltage ratings are determined by insulation design, creepage and clearance distances, bushing ratings, and core/winding configuration. The transformer must withstand continuous operating voltage plus overvoltages from switching and lightning, so basic insulation level (BIL) is carefully selected. System voltage class and grid standards dictate nominal ratings. Internally, turn insulation, barriers, and oil or solid dielectrics are designed to coordinate with external bushings and clearances, ensuring safe performance at the specified voltage levels.
enero 25, 2026 a las 3:04 pm en respuesta a: What is power factor of a transformer and why does it matter? #331873Kevin WhiteMiembroTransformer power factor reflects the phase angle between voltage and current drawn by the load. Low PF increases current and copper losses, reducing efficiency and capacity. Utilities account for PF when sizing transformers and setting tariffs.
enero 24, 2026 a las 3:09 pm en respuesta a: How does a Siemens power transformer meet utility specifications? #331687Kevin WhiteMiembroSiemens designs to IEC/IEEE standards, conducts type/routine tests, and supports custom grids with specified vector groups, impedances, and cooling classes.
enero 24, 2026 a las 5:23 am en respuesta a: What steps are involved in the repair of a power transformer? #331599Kevin WhiteMiembroRepeat of repair workflow: testing, disassembly, rewinding/insulation, OLTC servicing, refilling, testing.
enero 22, 2026 a las 11:25 am en respuesta a: What does power transformer mean in electrical engineering? #331247Kevin WhiteMiembroIt refers to a transformer used for voltage conversion in power systems at medium and high voltage levels-linking generation, transmission, and distribution networks.
enero 22, 2026 a las 7:28 am en respuesta a: What does a power transformer impedance table show? #331193Kevin WhiteMiembroIt lists percent impedance values for different tap positions and units, used for short-circuit calculations, parallel operation, and fault studies.
enero 21, 2026 a las 2:10 am en respuesta a: Where are power grid transformers installed in national networks? #330749Kevin WhiteMiembroGrid transformers reside in HV transmission yards, interties, converter stations, and major substations that connect regional and national grids.
enero 20, 2026 a las 4:39 pm en respuesta a: How is maximum efficiency of a power transformer determined? #330613Kevin WhiteMiembroEfficiency peaks when copper and core losses are balanced around nominal load. Test data under controlled loading and temperature reveals the efficiency curve.
enero 19, 2026 a las 6:52 am en respuesta a: What is an ABB control power transformer used for? #330302Kevin WhiteMiembroABB control power transformers provide low voltage power for breakers, relays, PLCs, switchgear controls and protection circuits. They isolate auxiliary circuits from primary busbars and ensure reliable operation of secondary control and metering equipment in substations and industrial plants.
Kevin WhiteMiembroA unit transformer feeds auxiliary loads of generators or turbines, stepping generator voltage down to service voltage for pumps, fans, controls, and station utilities.
enero 19, 2026 a las 3:39 am en respuesta a: What is a power transformer and how does it function? #330284Kevin WhiteMiembroA power transformer transfers electrical energy between voltage levels using electromagnetic induction. It consists of a magnetic core and windings. The primary winding creates a magnetic flux that induces voltage in the secondary. It provides galvanic isolation, enables efficient transmission and distribution, and manages voltage adaptation between generation, grid and loads.
enero 19, 2026 a las 12:25 am en respuesta a: What is a power box transformer used for in residential distribution? #330266Kevin WhiteMiembroA power box transformer (pad mounted or kiosk type) steps medium voltage down to low voltage for residential neighborhoods, apartment blocks or commercial campuses. It houses transformer, fuses and terminals in a tamper resistant enclosure suitable for public areas.
noviembre 12, 2025 a las 1:41 pm en respuesta a: Need pricing and delivery time for colloid mill for 3-6 t/h emulsion production. #327586Kevin WhiteMiembroThe CLM-4.1 colloid mill covers 3-6 t/h output and ensures stable particle size below 5 µm. Delivery and testing time are 4-6 weeks from order.
noviembre 12, 2025 a las 2:46 am en respuesta a: Need small-scale biodiesel equipment for about 200 L/day production. #327559Kevin WhiteMiembroThe small biodiesel reactor system for 200 L/day includes mixing, heating, and methanol recovery modules. It is suitable for pilot or educational use.
noviembre 11, 2025 a las 6:50 pm en respuesta a: Interested in the AVS-150 Vortex Layer Device. #327529Kevin WhiteMiembroThe AVS-150 vortex mill is suitable for intensive dispersion, activation, and mixing of solid-liquid systems. Detailed specifications and performance data will be provided.
noviembre 11, 2025 a las 3:35 pm en respuesta a: Need an oil purification system with a capacity of 9000 liters per minute, trailer-mounted with an enclosed chamber. #327514Kevin WhiteMiembroA high-capacity oil purification system of 9000 L/min (540 m³/h) can be designed as a custom CMM-series modification with multi-stage filtration and degassing. Technical proposal and configuration options will be provided.
-
AutorEntradas