What Electro Test & Maintenance does

Electro-Test and Maintenance, Inc. (ETMI) is a privately held, South Dakota-incorporated specialty services firm founded in 1980 and headquartered in Rapid City, SD. The company provides high-voltage electrical testing, maintenance, and commissioning services to electric utilities, power cooperatives, and power generation facilities primarily across the western United States, with field operations extending into the Desert Southwest via a Boulder City, NV outpost. Its 14-service catalog spans substation testing and maintenance, transformer field services, VLF cable testing (supporting cables up to 10 miles), infrared thermography (0.2°C detection), energized-equipment SF6 gas detection (FLIR GF306), recloser and voltage regulator maintenance (Cooper Power authorized since 1981), circuit breaker maintenance up to 345kV, battery system services (capacity discharge testing up to 750 amps), protective relay testing and calibration with PMU/RTAC installation, fabrication, power quality analysis, and Doble online monitoring system installation (IDD, Calisto, PD sensors, PD Guard).

The technical platform is built around certified proprietary instrumentation and instrumentation partnerships rather than software: computer-controlled test equipment simulating substation voltages from 2,400V to 24,940V, VLF AC test sets in the 0.01-0.1 Hz range, FLIR optical gas imaging, and Doble diagnostic devices for continuous bushings/CT monitoring. ETMI holds an Authorized Service Center relationship with Cooper Power Systems (since 1981) with over $350,000 in recloser parts inventory and $100,000 in voltage regulator parts inventory, a Doble Engineering test instrument sales agency covering six states (since 1982), and NETA Affiliate Member status. A 16,000 sq. ft. shop facility in Black Hawk, SD houses two overhead bridge cranes, a bake-out oven, a high-voltage bay, 6,000 gallons of transformer fluid, and fabrication capabilities.

ETMI monetizes through project-based and multi-year professional services contracts delivered via mobile field service units and at its shop. Pricing is opaque and quote-based given the specialized nature of work. Named enterprise customers include MidAmerican Energy, PacifiCorp, Basin Electric Power Cooperative, Tri-State G&T (Western Colorado Division, fourth consecutive year of infrared inspections across 106+ locations), and Platte River Power Authority. Marketing is minimal: a corporate website, direct phone/email contact, and partner-driven referral flow from Doble and Cooper Power Systems logos; the firm maintains no active social presence. Headcount sits in the 11-50 range and the company operates as founder/owner-led with no disclosed external capital, acquisitions, or leadership transitions.

Name

Electro Test & Maintenance

Legal name

Electro-Test and Maintenance, Inc.

Website

https://etmi.com

Company type

Private

Founded year

1980

Operating status

Operating

Headcount range

11–50 employees

Short description

Electro-Test and Maintenance, Inc. (ETMI) provides high-voltage electrical testing, maintenance, and commissioning services to electric utilities and power cooperatives across the western United States, operating as a Cooper Power Systems authorized service center since 1981.

Ownership category

akta.pro rank

Product category

Electrical Testing & Maintenance Services

NAICS

Electronic and Precision Equipment Repair and Maintenance (811210), Electric Power Transmission, Control, and Distribution (22112)

SIC

Services-Testing Laboratories (8734), Instruments For Meas & Testing Of Electricity & Elec Signals (3825)

akta.pro primary industry

Testing, Commissioning & Energization Services (HV) (EUAEABAI)

akta.pro secondary industries

Commissioning, testing & energization services (HVT, relay testing, SAT) (EUADAKAE), Electrical & Instrumentation (E&I) Maintenance for Energy Facilities (EUAEAGAJ)

Keywords

• High voltage testing
• Substation maintenance
• Transformer field services
• Protective relay testing
• Electrical commissioning

Headquarters

HQ city

Rapid City

HQ country

United States

HQ region

North America

Offices3 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Technology or R&D, Infrastructure, Supply Chain, Marketing or Sales

Revenue model

1. Testing and Maintenance Services: Professional services revenue generated through on-site high voltage electrical testing, maintenance, commissioning, and calibration services for power utility equipment including transformers, circuit breakers, protective relays, reclosers, voltage regulators, and battery systems. Services are provided both at client sites via mobile units and at the company facility.

Go-to-market motion1 record

Distribution channels3 records

Marketing channels3 records

Core offering

Electro-Test and Maintenance, Inc. (ETMI) provides on-site high voltage electrical testing, maintenance, and commissioning services for power utility substation equipment. The company delivers mobile field services and shop-based work covering transformers, circuit breakers, protective relays, reclosers, voltage regulators, battery systems, and cable testing, including infrared thermography, SF6 leak detection, VLF cable testing, and online monitoring installation for power utilities and electric cooperatives.

Product overview

Electro-Test and Maintenance, Inc. is a high voltage electrical testing and maintenance service company founded in 1980, serving the power industry primarily in the western United States. The company operates as a single-site service organization offering 14 distinct but interconnected service offerings centered around substation and power equipment testing, maintenance, and commissioning. Core services include Substation Testing & Maintenance (the umbrella service encompassing all substation equipment), Transformer Field Services, VLF Cable Testing, Commissioning Services, Battery System Services, Infrared Thermography Scanning, Infrared SF6 Gas Detection, Recloser Maintenance, Voltage Regulator Maintenance, Circuit Breaker Maintenance, Fabrication Services, Protective Relaying Services, Power Quality/Disturbance Analysis, and Online Monitoring Installation Services (Doble IDD). The company holds authorized service center status from Cooper Power Systems (since 1981) and serves as a sales agent for Doble Engineering Company (since 1982). A 16,000 sq. ft. facility in Black Hawk, SD provides high voltage testing capability up to 24,940V and stocks over $350,000 in recloser repair parts and $100,000 in voltage regulator parts. Services are delivered through both shop-based and mobile service units, with additional equipment stationed in Boulder City, NV for desert southwest clients.

Differentiator

Problem solved

Functional benefit

Products and services

• Substation Testing & Maintenance Comprehensive substation testing and preventive maintenance program covering visual inspection, infrared thermography, oil analysis, insulation testing, SF6 gas handling, cable testing, oil handling, and testing of power transformers, load tap changers, reclosers, voltage regulators, circuit switchers, protective relays, power circuit breakers, fuse testing, ground mat testing, and battery systems for power utilities.
• Transformer Field Services Turnkey transformer field services from rail siding to final installation including assembly, bushing replacement, internal inspection, leak repair, relocation, tap changer repair, vacuum/oil processing, retro-fill, bulk oil supply, and field testing (Doble power factor, insulation resistance, SFRA, turns ratio) for power utilities and generation facilities.
• VLF Cable Testing Very Low Frequency cable testing using AC voltages in 0.01 Hz to 0.1 Hz range enabling proof testing of medium voltage cables up to 10 miles in length, supporting XLPE, PE, EPR, and PILC cable types, with optional Tan-Delta module for cable condition monitoring.
• Commissioning Services Start-up testing and commissioning of electrical installations supervised by electrical engineers to ensure proper installation, operation, calibration, wiring, and design of equipment and protection schemes, producing benchmark testing results for future baseline comparisons.
• Battery System Services Battery bank and charger system services including training, impedance testing, capacity discharge testing up to 750 amps, system upgrades, and real-time individual cell voltage monitoring covering flooded lead acid, NiCad, and VRLA battery types for utility substation DC backup systems.
• Infrared Thermography Scanning Infrared scanning service detecting temperature differences down to 0.2°C to identify internal issues in substations, overhead lines, transformers, circuit breakers, switchgear, bus bars, connectors, motors, and fuses, diagnosing loose connections, unbalanced loads, high resistance connections, and overloaded circuitry.
• Infrared SF6 Gas Detection High resolution SF6 gas leak detection using FLIR Systems GF306 infrared gas detection camera tuned to 10.3-10.7 µm wavelength, enabling precision leak detection of gas insulated equipment while energized without taking equipment offline.
• Recloser Maintenance Complete recloser maintenance services (shop and on-site field) including bushing inspection, mechanism/coils/contacts detanking, gasket and parts replacement, oil filtration, tank cleaning, complete testing per CPS requirements, repainting, and renumbering. Authorized Cooper Power Systems Service Center since 1981.
• Voltage Regulator Maintenance On-site voltage regulator maintenance for all makes and models (Cooper Power, McGraw-Edison, GE, Siemens, AC) including turns ratio test, Doble test, oil filtration and degassing, PT ratio test, internal inspection, micro-ohmmeter windings/contacts testing, and control panel upgrades.
• Circuit Breaker Maintenance Maintenance service for switchgear and outdoor equipment from 15kV up to 345kV gas breakers, including commissioning, repair, refurbishment, verification that breakers and protective relaying work properly, SF6 gas leak detection and repair, and on-site field services.
• Fabrication Services Custom fabrication services including switchboard and 19-inch rack panel fabrication, on-site relay upgrades, switchboard panel installation and wiring, and SCADA/load management installations.
• Protective Relaying Services Protective relay testing, calibration, and maintenance using computer controlled test equipment for high accuracy and repeatability, including Phasor Measurement Unit (PMU) system installation with RTAC devices, helping reduce mis-operations, nuisance trips, and identify system coordination issues.
• Power Quality/Disturbance Analysis Power quality and disturbance analysis for diagnosing power system anomalies including demand profiles, harmonics, voltage issues, transients, power auditing, inrush, and energy analysis.
• Online Monitoring Installation Services (Doble IDD) Installation and configuration services for Doble online monitoring systems including Doble IDD (Intelligent Diagnostic Device for Bushings and CTs), Doble Morgan Schaffer Calisto Systems, Doble Partial Discharge Sensors, and Doble PD Guard Systems, providing continual online monitoring with embedded expert systems for abnormality detection and remote alerting.

Quantifiable outcome

• Detect temperature differences down to 0.2°C with infrared thermography
• +3 more outcomes

Named customers5 records

Segments2 records

Ideal customer profiles2 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature5 records

Partnerships

Three partnerships are on record, tiered core.

• Cooper Power SystemscoreTechnology or IntegrationETMI has been an Authorized Service Center for Cooper Power Systems since 1981. This partnership provides factory authorization for servicing reclosers, regulators, and distribution transformers. ETMI stocks over $350,000 of recloser repair parts and $100,000 of voltage regulator parts for all makes and models. The partnership enables access to genuine Cooper replacement parts, technical support, and exclusive repair authorization.
• Doble Engineering CompanycoreTechnology or IntegrationETMI has been a Doble test instrument sales agent since 1982, representing Doble products in North Dakota, South Dakota, Nebraska, Montana, Wyoming, and Colorado. ETMI uses all Doble test instruments for field services and can provide comprehensive field training to clients. ETMI is certified to install and maintain Doble's IDD (Intelligent Diagnostic Device), Calisto systems, Partial Discharge sensors, and PD Guard systems.
• InterNational Electrical Testing Association (NETA)coreOthersETMI is an Affiliate Member of NETA, the InterNational Electrical Testing Association. This membership demonstrates commitment to industry standards and best practices in electrical testing and maintenance services.

Scale indicators6 records

Recent moves6 records

Expansion highlights5 records

Broad incumbents

• Quanta Services: Largest publicly traded infrastructure-services provider to the electric power industry; competes with ETMI on utility substation build, testing and maintenance work as part of a much broader portfolio.
• Eaton (Cooper Power Systems division): Owner of Cooper Power Systems — the OEM for which ETMI is an authorized service center — and a global supplier of substation and HV equipment; sets the equipment, warranty and authorized-partner framework ETMI operates within.
• Electrical Consultants Inc. (ECI): Established engineering, procurement and construction firm serving electric utilities across transmission, distribution and substations; broader scope than ETMI but overlaps on substation commissioning and testing.
• EMCOR Group: Diversified electrical and mechanical services contractor with utility-adjacent testing and maintenance capabilities; provides a public-market benchmark for ETMI's service model, though with a much wider scope.

Direct peers

• RESA Power: Specialty transformer and electrical testing/maintenance provider with NETA-certified crews serving utility and industrial customers across North America; overlaps directly with ETMI's transformer field services, breaker maintenance and commissioning offerings.
• Shermco Industries: Large U.S. provider of electrical testing, maintenance and commissioning services for utilities and industrial customers; directly comparable to ETMI in HV acceptance and maintenance testing, relay testing, and transformer services, but at substantially greater national scale.
• Mangan Inc. Engineering and field services firm focused on HV substation, transmission and power-plant testing and commissioning; competes with ETMI for utility relay testing, commissioning, and maintenance contracts.
• CE Power Engineered Services: Power-system testing, maintenance and commissioning services firm (NETA-affiliated) covering transformers, breakers and relays; closely matches ETMI's service line and customer profile.

Others

• Doble Engineering Company: Manufacturer of the diagnostic instruments ETMI sells and uses (IDD, Calisto, PD sensors) and its training partner; not a direct competitor but the upstream technology supplier critical to ETMI's service delivery.

Regional players

• Irby Utilities / Sentry Electric: Regional utility electrical services and testing providers with NETA-style HV testing crews; comparable business model to ETMI but different geography, illustrating the regional-services landscape ETMI operates in.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat6 records

Key risks6 records

Key highlights6 records

Customer concentration

• LinkedInlinkedin.com/company/electro-test-inc

Compliance1 record

Revenue estimate

Valuation estimate

Number of profiles

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Electro Test & Maintenance