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David Lee

David Lee

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Viewing 20 posts - 1 through 20 (of 56 total)
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  • in reply to: Best portable transformer oil breakdown voltage analyzer #342245
    David Lee
    Member

    You’re absolutely right: useful BDV evaluation goes beyond maximum voltage and automation — repeatability depends on how well the instrument controls test conditions such as voltage ramp rate, immediate shutdown on breakdown, and consistent sample handling (stirring, temperature control and timing). That consistency is essential when results feed trend analysis rather than one-off checks, so support for IEC 60156/ASTM D877/ASTM D1816 procedures, the ability to store and export results to a PC, and the option to create and run custom procedures are practical features that turn field testing into reliable diagnostics across sites and operators.

    For on-site work where portability and repeatable procedure control matter, the TOR-80 family is designed around those requirements. The battery-powered TOR-80A supports autonomous field operation (about eight hours per charge), performs breakdown testing up to 80 kV, disconnects test voltage almost instantaneously on breakdown (on the order of 4 microseconds), and supports standard and user-defined test procedures with PC data transfer for databases and reporting. If you want, I can summarize how the TOR-80A and the non-battery TOR-80 compare against your specific needs (typical oil types, required BDV range, data workflow and frequency of trend monitoring).

    in reply to: why power is constant in transformer? #331979
    David Lee
    Member

    In an ideal transformer, power remains constant because energy cannot be created or destroyed. When voltage steps up, current steps down proportionally, and vice versa. Real transformers introduce losses due to hysteresis, eddy currents, resistance, and cooling systems, so the primary power equals secondary power plus losses.

    David Lee
    Member

    Typical roles require electrical engineering backgrounds, knowledge of IEC/IEEE standards, factory testing, DGA/PD diagnostics, and field commissioning competencies.

    David Lee
    Member

    Sensors track oil and winding temperatures, while SCADA trends load, PF, and DGA data to detect stresses early.

    David Lee
    Member

    It represents a step-up or step-down transformer symbolically to indicate voltage transformation, isolation, or phase shift in circuit diagrams.

    in reply to: What applications use Hyundai power transformers? #330843
    David Lee
    Member

    Hyundai power transformers serve utility transmission and distribution networks, industrial plants, petrochemical facilities, and data center substations.

    in reply to: What topics are covered in a power transformer handbook? #330776
    David Lee
    Member

    Handbooks typically cover design theory, materials, electromagnetic modeling, thermal design, dielectric systems, OLTC mechanics, cooling classes (ONAN/ONAF/OFWF/GF), standards, factory testing, installation, protection schemes, diagnostics (DGA, PD, tan-delta, FRA), maintenance, failure modes, and asset management. Case studies and utility practices are often included.

    David Lee
    Member

    Yes – AVS (vortex layer) technology can be applied to large volumes, but it’s important to think of it as an intensification reactor, not a “single giant filter.” The working zone is very intense, so required residence times are usually short (seconds to tens of seconds), which supports high throughput. Scaling is typically done by larger-flow reactors and, more realistically, by running multiple units in parallel to keep the same hydrodynamics and treatment quality. For mining wastewater, the real volumetric capacity will depend on your chemistry (pH/reagents), solids load, target metals, and the downstream separation step (settling/DAF/filtration), because AVS accelerates reactions but you still need to remove the formed precipitate.

    David Lee
    Member

    Getting selenium to ppb is usually less about “stronger mixing” and more about selenium speciation + a polishing step. AVS (vortex layer) can intensify redox/precipitation and improve reagent contact, so it may help as a reaction accelerator in a chemical treatment train (similar to how GlobeCore describes AVS intensifying heavy-metal reduction/precipitation processes). But on its own, AVS is not a selective Se separator. In mining waters, iron co-precipitation works well for selenite, but removes very little selenate, and ppb targets typically require downstream clarification/filtration and often a final “polishing” technology (anion exchange, membranes, etc.). So: Yes, ppb is achievable, but usually with a multi-stage scheme (convert selenate ? selenite, co-precip/filtration, then polishing). AVS can be a useful intensifier in the reaction step-just don’t expect it to be the single device that guarantees ppb by itself.

    David Lee
    Member

    Fault currents, arcing, and rapid thermal/pressure rise in oil lead to tank rupture if protections fail or are delayed.

    in reply to: How are power transformer design calculations performed? #330498
    David Lee
    Member

    Design calculations address core cross-section, flux density, copper losses, impedance, insulation levels, and thermal rise. Standards and load profiles guide the final design.

    in reply to: Interested in bitumen emulsion storage equipment. #327637
    David Lee
    Member

    Bitumen emulsion storage tanks are available in capacities from 10 to 100 m³ with heating coils, mixers, and temperature regulation.

    David Lee
    Member

    The TOR-100 oil breakdown voltage tester measures dielectric strength of transformer oils up to 100 kV in accordance with IEC 60156. We will provide pricing, availability, and information about official supply channels.

    David Lee
    Member

    The CMM-4.0LT unit can process transformer, turbine, and gear oils if viscosity and contamination levels are within standard limits. We can arrange service or provide technical guidance in the preferred language.

    David Lee
    Member

    The CMM series purification systems remove moisture, gases, and solid contaminants from transformer oil. Available capacities range from 600 to 12 000 L/h. We’ll provide options and pricing details.

    David Lee
    Member

    The CMM-R2 is a compact regeneration plant for 2 m³/h transformer oil processing. It removes acids, sludge, and oxidation products, restoring oil quality. A detailed quotation will be sent shortly.

    David Lee
    Member

    Transformer oil filtration systems by GlobeCore are designed to remove water, gases, and solids. Available models (CMM-0.6 to CMM-12) feature automatic controls, vacuum systems, and stainless-steel piping. Full specifications can be provided upon request.

    in reply to: What does a transformer DGA test show? #325145
    David Lee
    Member

    The DGA (Dissolved Gas Analysis) test detects fault gases in oil. Before running the test, oil should be degassed to avoid false results. GlobeCore offers degassing units that prepare oil for accurate DGA readings and extend equipment life.

    in reply to: What is Shell Turbo 32 and where is it applied? #323758
    David Lee
    Member

    Shell Turbo 32 is a light-viscosity mineral turbine oil commonly used in compressors, pumps, and turbines. GlobeCore treatment plants remove particulates and water, extending the oil’s lifespan.

    David Lee
    Member

    Most transformers use inhibited mineral insulating oils, but esters and silicone fluids are also common in specific applications. GlobeCore purification plants maintain all these oil types, ensuring reliability and extended service life.

Viewing 20 posts - 1 through 20 (of 56 total)

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