RHM International, LLC

Innovative High Reliability High Voltage Equipment for the Power Grid

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    • RHM International current transformer typesCurrent Transformers
      • LRGBJ Series – up to 550kV
      • LRGBJ-ZH Cascade Series – above 220kV
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    • Dry Insulation high voltage transformer bushings by RHM InternationalTransformer Bushings
      • RIF® – FGRBW Tough Series
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    • RHM International high voltage wall bushingsWall Bushings – Special Bushings
      • STB Wall Bushings Specifications
      • STB-L Series: Wall Bushing with CT
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    • cable termination by RHM InternationalHV DRY TYPE OUTDOOR CABLE TERMINATOR
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    • Electronic Combined Voltage and Current Transformer REVCT35-1000 Series 35 kV – 1000 kV by RHM InternationalIEC 61850 Ready and NCITs
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  • Technology
    • 1Our Technologies
      • HV DryShield® for CT’s & Wall Bushings
      • RIF® Insulation for Transformer Bushings & Cable Terminators
    • smart-monitoringSmart Monitoring
      • Built-in Condition Monitoring
      • Bushing based Transformer PD Monitoring
    • The-Dry-Type-RIF-Bushing_The-New-Technology-in-HV-Bushings-1Publications
      • BIIT Bushings: Intelligent HV bushings w/ integrated low power voltage and current transformers
      • HV DryShield® – A dry type HV insulation system for extreme environments
      • RIF ® bushings The paperless, dry-type bushing technology
      • The Dry Type RIF ® Bushing: New Technology in HV Bushings
      • Advances in Bushings Technology – Integrated Monitoring Systems
    • 3Product Specification Sheets
      • Current Transformers
      • Wall Bushings
      • IEEE Bushings
      • IEC Bushings
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Technology

Our Technologies

Go Paperless: A real High Voltage reliable Dry type insulation

“Dry” insulation is not a new concept in electrical grid equipment. However, the initial designs have been associated with longevity problems and medium voltage limits.

Now it can be said that dry technologies, like HV DryShield® and RIF®, are clearly performing as well or better than alternative cast epoxy, oil or resin impregnated paper, or gas based insulations; it also lasts longer and is being successfully operated at Extra High Voltages (EHV).

We have created, developed, qualified, and manufactured those two distinct dry type technologies for two distinct functional purposes.

1. HV Dry Shield® for CTs and Wall Bushings
2. RIF® for Transformer Bushings and Cable Terminals

HV DryShield® for CT’s & Wall Bushings

HV DryShield® is a proprietary condenser finely-graded insulation using composite materials such as PTFE (Poly Tetra Fluoro Ethylene) as core insulation. A uniformly distributed electric field design eliminates stress points and is complemented with external silicone rubber insulation. A unique combination of design, materials and manufacturing know-how results in a very robust insulation with minimum flashover risk and very low partial discharge and tanδ values.

HV DryShield® is used both in our Current Transformers and Wall Bushings.

schematic drawing of HV DryShield® used both in our Current Transformers and Wall Bushings of RHM International

The HV DryShield® dry condenser graded insulation constitutes the independently sealed, weather proof primary winding of the LRGBJ series Current Transformer or the STB series Wall Bushing

STB-L series Wall Bushings with current transformers by RHM International

STB-L series Wall Bushings with CT

RIF® Insulation for Transformer Bushings and Cable Terminators

RIF® is a proprietary paperless condenser graded insulation system composed of layers of fiberglass impregnated with epoxy resin between capacitive screens used to form a uniform core insulation. RIF®, provides superior electrical, mechanical and thermal operational margins. It is impervious to humidity in a maintenance-free, leak-free and explosion-free package. As with all RHM International products a high quality silicone rubber is used as outer insulation; it provides superior pollution and climate resistance enabled by the uniformly controlled electrical field profile.

RIF® is used both in our transformer bushings and cable terminators.

diagram of RHM RIF proprietary paperless condenser graded insulation system composed of layers of fiberglass impregnated with epoxy resin between capacitive screens used to form a uniform core insulation used in transformer bushings and cable terminators

RIF® in Bushings and Cable Terminations

A simple and rigorously controlled production process allowing design flexibility with consistent Quality and one of the best lead times in the industry.

Schematic of RIF high voltage insulation assembly process used in RHM transformer bushings and wall bushings

Installation & Testing

Installing our products is as easy as "plug & play". No structural modification required, no seal to check, no oil level or gas leakage rate measurement to perform. Furthermore, our products are often   lighter and smaller than conventional current transformers and wall bushings.  Replacement, upgrade and installation then are simple, trouble-free operations.

RHM installation and testing rig

Products Specification Sheets  (PDFs)

  • Current Transformers
  • Wall Bushings
  • Transformer Bushings
    Brochure for IEEE Bushings
    Brochure for IEC Bushings
  • Cable Terminals

Technology

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