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

Oilfield & Rig Electrical:
Supply, Sourcing
& Custom Fabrication

Oilfield electrical runs on equipment that was built decades ago: and the OEMs behind it have changed, merged, or disappeared entirely. Edmundson Industrial supplies, sources, and builds for the oilfield: SCR house components, Ross Hill Controls parts, NOV and Canrig electrical, drawworks drives, mud pump starters, and custom VFD and SCR house fabrication.

What We Handle

  • SCR house components & replacement parts
  • Ross Hill Controls: drives, modules, parts
  • NOV, Canrig & National Oilwell electrical
  • Drawworks motors, drives & controls
  • Mud pump starters & motor control
  • AC & DC rig electrical: all systems
  • Custom VFD house & SCR house builds
  • Legacy rig MCC panels & switchgear
SCR House Components
Ross Hill Controls
NOV Electrical
VFD House Builds
Rig-Down Response
Custom Fabrication

Equipment Built to Last, Support That Didn't

Drilling rigs were designed to run for decades, and the electrical systems on them reflect that. SCR houses, drawworks drives, mud pump motor controls, and topside electrical infrastructure were engineered for long service lives. But the companies that built them (Ross Hill Controls, older National Oilwell divisions, legacy SCR manufacturers) have been acquired, restructured, or discontinued their support programs.

Standard industrial distribution isn't built for oilfield work. Distributors don't stock SCR components, don't understand rig electrical architecture, and can't help when a rig-down situation requires urgent response. That's where Edmundson Industrial comes in. We know the equipment, we know the part numbers, and we maintain supply channels for the electrical components that keep rigs running.

Whether you need a replacement drive module for a Ross Hill SCR, motor control components for a mud pump, or a complete custom VFD house built to your spec, send us what you have and we'll respond with options.

  • Oilfield-specific electrical knowledge: we understand the systems and the urgency
  • Supply and sourcing for discontinued, legacy, and hard-to-find rig electrical components
  • Ross Hill Controls, NOV, Canrig, legacy SCR systems: we know these product lines
  • Custom SCR house and VFD house builds for rig upgrades and replacements
  • Rig-down response: fast turnaround on urgent parts requests when feasible
Submit an Oilfield Parts Request

Oilfield Electrical at a Glance

  • Primary Specialty SCR house components, Ross Hill Controls, NOV electrical, and legacy rig motor control
  • Rig Systems Drawworks, mud pumps, top drives, rotary tables: AC and DC rig systems
  • Fabrication Custom VFD houses and SCR houses built to spec for rig upgrades and fleet replacement
  • How to Submit Part number, nameplate data, OEM documentation, photos, or equipment description
  • Condition New, surplus, and reconditioned: condition is stated clearly with every quote
  • Response Same-day response on urgent rig-down situations when feasible

What We Supply & Source

Edmundson Industrial handles a broad range of oilfield electrical requirements, from individual replacement components to complete drive systems and fabricated assemblies.

SCR Systems

SCR House Components

Silicon Controlled Rectifier systems power the DC drive equipment on conventional drilling rigs. We source components across legacy and current SCR architectures.

  • SCR modules, thyristors & power stacks
  • SCR control cards & firing boards
  • Rectifier bridges & crowbar circuits
  • Gate drivers & pulse transformers
  • SCR house cooling components
  • Replacement DC drives for rig systems
Motor Control

Drawworks & Mud Pump Electrical

Motor control for the primary rig loads, drawworks hoisting, mud pump drives, and rotary table systems. DC and AC architectures.

  • Drawworks motor control components
  • Mud pump VFDs & motor starters
  • Rotary table drive components
  • DC motor controllers & armature contactors
  • Dynamic braking resistors & choppers
  • Motor protection relays & overloads
Top Drive & Automation

NOV, Canrig & Top Drive Controls

Top drive control systems from National Oilwell Varco, Canrig, and legacy manufacturers. Drive electronics, control panels, and field replacement components.

  • Canrig top drive control components
  • NOV top drive electrical parts
  • Top drive VFD components & drives
  • Top drive control panels & enclosures
  • Resolver & encoder feedback components
  • PLC and control system components
Rig Distribution

Rig Switchgear & MCC

Electrical distribution, motor control centers, and switchgear for rig power systems, both legacy DC rig configurations and modern AC rig architectures.

  • Rig MCC buckets & starter units
  • Rig switchgear sections & breakers
  • Bus sections, bus duct & hardware
  • Rig power distribution panels
  • Generator switchgear & breakers
  • Control transformer & power supply components

The Industry Standard for Rig Electrical, and One of the Hardest Lines to Source

Ross Hill Controls defined the SCR-based DC drive architecture that powered a generation of drilling rigs. Their drive systems, control consoles, and motor control equipment became the standard configuration for land rigs and offshore platforms throughout the industry's most active decades.

The challenge today is that Ross Hill's product line went through multiple ownership transitions. Support and parts availability through standard channels is inconsistent at best. When a rig running Ross Hill equipment goes down, finding genuine replacement parts or compatible substitutes requires oilfield-specific sourcing experience.

Edmundson Industrial maintains supply channels for Ross Hill Controls components. If you have a part number, a model number, or a description of what failed . Send it to us. We'll check availability across surplus, reconditioned, and new-old-stock inventory and respond with what we can locate.

  • Ross Hill SCR drive modules: multiple series and frame sizes
  • Ross Hill control consoles and drillers panel components
  • Gate drive cards, firing boards, and control PCBs
  • Compatible replacement components where OEM parts are unavailable
  • New-old-stock and reconditioned units: condition always stated clearly

Commonly Requested Ross Hill Parts

These are the Ross Hill Controls components we receive requests for most frequently. If your part isn't listed, send us the part number, we'll check availability.

  • SCR drive modules: drawworks, rotary, mud pump series
  • Firing boards & gate drive PCBs
  • Control cards: speed reference, current limit, feedback
  • Power thyristors & SCR stacks
  • Crowbar modules & snubber circuits
  • Drillers console control components
  • Power supply boards & regulator cards
  • Contactors & armature switching components
  • Field supply rectifiers & regulators
  • Compatible Mentor II / III replacement drives

How to Submit a Ross Hill Request

Send us the Ross Hill part number, model designation, or a description of the failed component. Photos of nameplates and the board or module itself help us confirm compatibility. We respond with availability and pricing as quickly as possible.

SCR House & VFD House Builds

When a rig's power conversion infrastructure reaches end of life, or when an operator is transitioning from DC to AC drive architecture, complete house replacement or rebuild is often the most economical path. Edmundson Industrial builds custom SCR houses and VFD houses to customer specification.

This isn't off-the-shelf product, it's fabricated to match your rig's footprint, power requirements, and interface specifications. We work from your documentation, from field measurements, or from the existing unit when a like-for-like replacement is the goal.

  • Custom SCR house builds: replacement or upgrade configurations
  • VFD house fabrication for AC rig conversion projects
  • Built to customer footprint, power rating, and interface spec
  • Enclosure fabrication, bus work, and internal component assembly
  • Integration with existing rig distribution and control systems
  • Documentation package included: drawings, BOM, wiring diagrams
Request a Fabrication Quote

What Goes Into a VFD House Build

A complete VFD house for rig application is a fabricated assembly, not a product you order from a catalog. The scope typically includes enclosure construction, bus work, VFD installation and wiring, control system integration, and testing before delivery.

  • Structural enclosure: NEMA rating, access, ventilation to spec
  • Main bus and branch circuit distribution
  • VFD selection and mounting: matched to motor and load
  • Input filtering, line reactors, and harmonic mitigation
  • Control wiring: interface to driller's console and PLC
  • Dynamic braking and regeneration components
  • Protection devices: fusing, breakers, ground fault
  • Instrumentation: meters, indicators, and alarms
  • Factory test and burn-in prior to site delivery
  • As-built drawings and installation documentation

How to Submit an Oilfield Parts Request

Oilfield parts requests work differently from standard industrial orders. The more information you can provide, the faster and more accurately we can respond. Here's what helps.

Part Numbers & Model Numbers

Ross Hill Controls, NOV, Canrig, and legacy SCR manufacturers used consistent part numbering. If you have the part number (from the nameplate, the manual, or a previous order) that's the most direct path to a fast quote.

Nameplate Data & Photos

For components where the part number is worn or missing, a clear photo of the nameplate (or photos of the unit itself, the PCB, or the enclosure label) gives us what we need to identify the component and locate compatible replacements.

OEM Documentation

If you have the original equipment manual, wiring diagrams, or parts lists for the rig system (even partial documentation) include it with your request. This helps us confirm exact replacements and identify compatible alternatives when OEM parts aren't available.

System Context & Urgency

Tell us what rig the parts are for, what failed, and how urgent the situation is. Rig-down situations get priority response. If you have a commissioning or maintenance window with a hard deadline, let us know, we'll work backward from your date.

Submit Your Oilfield Request

Use the RFQ form or email directly. Either works, include as much detail as you have. We respond as quickly as possible, with priority turnaround for rig-down situations.

  • Part number, model number, or catalog number
  • OEM or manufacturer (Ross Hill, NOV, Canrig, etc.)
  • Photos of nameplate, PCB, or failed component
  • Rig name and rig type (land, offshore, etc.)
  • Quantity required and urgency level
  • Any existing documentation or wiring diagrams
Submit via RFQ Form
Location Houston, Texas

Manufacturers & Systems We Work With

Oilfield electrical spans legacy and current manufacturers across drive systems, controls, and distribution. These are the brands and product lines we handle most frequently.

Ross Hill Controls
SCR drive systems, drillers consoles, and motor control for conventional DC rig architecture. One of the most requested legacy oilfield brands.
NOV / National Oilwell Varco
Top drive systems, rig electrical components, drawworks controls, and National Oilwell legacy product lines.
Canrig Drilling Technology
Top drive control systems and electrical components across Canrig product generations. Now part of NOV.
Varco International
Legacy Varco rig equipment and electrical components prior to the NOV consolidation.
Eaton / Cutler-Hammer
Motor control, circuit protection, and switchgear used in rig electrical distribution and motor control applications.
ABB
VFDs, DC drives, and motor control used in modern AC rig conversions and top drive systems. Includes legacy Asea Brown Boveri and BBC product lines.
Siemens / Robicon
Medium voltage VFDs, rig drive systems, and Robicon Perfect Harmony drives used in offshore and land rig applications.
General Electric
DC drive systems, SCR components, and GE motor control equipment widely used in conventional rig electrical architecture.

Have an Oilfield Parts Request?

Send us a part number, nameplate data, or a description of what you need. Partial information is fine. We'll respond with availability, condition, and pricing. Rig-down or urgent? Call us directly at (832) 975-8827 for the fastest response.