Based in Houston, TX. Serving Industrial Customers Across Texas & the United States.

Ross Hill / NOV Drilling
Electrical Components

SCR system components, firing boards, control cards, SCR modules, and related hardware for Ross Hill and NOV drilling rig electrical systems. Sourced for rig electricians, OIMs, drilling superintendents, and contractor procurement teams across the Gulf Coast and Permian Basin. If the rig is down, send us the part number or the board ID.

Components We Source

  • SCR firing boards and gate trigger boards
  • SCR modules and SCR stacks
  • Armature feedback boards
  • Field supply boards and field regulators
  • Control cards: Ross Hill and NOV platforms
  • Rectifier bridges (single and three-phase)
  • SCR house fuse blocks and fusing
  • SCR house contactors and power contactors
  • Toshiba, Mentor II, Mentor MP drive boards
Ross Hill Controls
NOV Drilling Systems
SCR System Components
Gulf Coast & Permian
Houston, TX

SCR House Components for Active and Legacy Rig Systems

Ross Hill Controls and NOV drilling electrical systems have been the backbone of SCR-driven drilling rigs across North America for decades. The boards and modules inside these systems are not available through general electrical distributors. When a firing board fails mid-tower, or an SCR module trips and won't reset, the part comes from a specialty source or a supply contact who knows what they're looking at.

Edmundson Industrial sources these components for drilling contractors, rig owners, and maintenance teams operating in Houston, the Gulf Coast, and the Permian Basin. We understand that an idle rig is not an abstract problem and that "let me check on availability" needs to happen fast.

  • Ross Hill Controls SCR system boards: firing, gate trigger, armature feedback, field supply
  • NOV drilling rig electrical: control cards, SCR modules, power components
  • Toshiba VFD drive boards used in drilling applications
  • Mentor II and Mentor MP DC drive components for SCR drive circuits
  • Rectifier bridges, fuse blocks, and SCR house contactors
  • Condition disclosed on every quote: new, surplus, tested, or reconditioned

Supply Summary

  • PlatformRoss Hill Controls, NOV drilling systems, Toshiba, Mentor II, Mentor MP
  • Board TypesFiring boards, gate trigger boards, armature feedback, field supply, control cards
  • Power ComponentsSCR modules, SCR stacks, rectifier bridges, fuse blocks, power contactors
  • ConditionNew, surplus, or reconditioned: disclosed clearly on every quote
  • Service AreaHouston, Gulf Coast, Permian Basin, Eagle Ford, and nationwide
  • How to SubmitBoard ID, part number, system designation, or nameplate photo

Ross Hill and NOV Components We Supply

These are the categories we handle most often. If the component is part of an SCR house, VFD house, or rig power distribution system, send us what you have.

Firing & Trigger Boards

SCR Firing Boards and Gate Trigger Boards

The firing board is typically the first failure point in an SCR drive circuit. These are proprietary boards specific to the Ross Hill and NOV platforms and are not interchangeable with general-purpose SCR controllers.

  • Ross Hill SCR firing boards: various series and revision levels
  • Gate trigger boards for SCR stack assemblies
  • NOV drilling system firing and control boards
  • Synchronization boards and pulse transformer boards
  • Board ID, revision level, and part number accepted for identification
SCR Modules & Stacks

SCR Modules, Stacks, and Rectifier Bridges

Power semiconductors in SCR houses take abuse from inrush, heat, and fault conditions. Module replacements require matching the original voltage and current ratings exactly. Do not substitute without confirming the specifications.

  • SCR modules: single, dual, and bridge configurations
  • SCR stack assemblies for high-current applications
  • Three-phase and single-phase rectifier bridges
  • Snubber networks and gate resistors
  • Ratings accepted: voltage blocking, on-state current, gate requirements
Control & Feedback Cards

Armature Feedback, Field Supply, and Control Cards

Armature feedback boards regulate the motor voltage feedback loop in DC SCR drive systems. Field supply boards regulate field current. Both are platform-specific and require matching to the drive system and motor parameters.

  • Armature voltage feedback boards: Ross Hill and NOV
  • Field supply boards and field regulators
  • Tachometer feedback and speed reference cards
  • Mentor II and Mentor MP control cards and option boards
  • I/O expansion cards and communication boards
Power Distribution

Fuse Blocks, Contactors, and SCR House Power Components

The power distribution hardware inside an SCR house: fuse blocks, bus connections, power contactors, and control power components. These are often overlooked until a fuse block fails or a contactor welds during a fault event.

  • SCR house fuse blocks: DIN rail and panel-mount
  • High-amperage fusing for SCR protection circuits
  • Power contactors and reversing contactors
  • Control power transformers for SCR house auxiliary circuits
  • Bus bars, terminal blocks, and control wiring components

What Helps Us Find It Faster

These boards are not in a general electrical catalog. The faster we can identify the exact revision and platform, the faster we can check availability. More information is always better, but we can often start with just a board ID or a clear photo.

  • Board ID or part number from the board silkscreen or label
  • System designation: Ross Hill series, NOV model, Toshiba drive designation
  • Revision level or date code if visible on the board
  • Rig name or system description for context (optional but helpful)
  • Quantity and urgency level (so we can prioritize the search)
  • Photos of the board and surrounding components if available
Submit a Request

Contact for Urgent Requests

Rig-down situations get attention first. If the rig is idle and you need a board or module immediately, call or email with "URGENT" in the subject and the part identification you have. We'll start checking availability while you're still on the phone.

Board ID Part Number Revision Level System Designation Photo Quantity

Condition is always disclosed on the quote. We do not ship components described as something they are not.

Submit Parts Request

Ross Hill, NOV, or Related SCR System Parts?

Send the board ID, part number, or a photo. We'll check availability and get back to you.