Electrical contractors for data centres and critical power
Contractors that take power from the site supply to the load: medium and low-voltage distribution, cable and containment, switchboards, earthing and standby plant. Filterable by service and country.
North America
View region →48 Electric LLC is an electrical contractor based in Chandler that services the metro Phoenix area and the rest of Arizona under ROC 330786. Its stated mission critical capabilities cover high, medium and low voltage distribution, switchgear and paralleling switchgear, generators, uninterruptible power supply and battery systems, switchboards, transformers, power distribution units, remote power panels and automatic transfer switches. Its portfolio records a two megawatt build-out, sixteen remote power panel installs and power distribution unit installs in live data centre environments.
Aldridge Electric is an electrical and civil site infrastructure contractor headquartered at 844 East Rockland Road, Libertyville, Illinois. Its mission critical market covers hyperscale data centres, where it self-performs medium voltage systems, substations, duct banks, outside plant fibre and temporary power. It provided the power and communications site package for a data centre in DeKalb, Illinois.
Bergelectric is an electrical contractor with an office at 3255 E. Elwood Street in Phoenix and data centres among its listed markets. Its data centre page names CyrusOne in Phoenix among its selected projects and states more than ten million square feet of data centre construction and 10,000 miles of conduit installed across the country.
Cannon and Wendt Electric Co. is an electrical contractor with its office on North 16th Street in Phoenix and a Tucson operation trading as Gilbert Electric. Its portfolio records continuing work at the Iron Mountain AZP1 data centre in Phoenix, a 588,000 square foot facility, covering customer suite build-outs and critical infrastructure from 2009 to the present.
CEC Facilities Group is a specialty electrical, mechanical and technology contractor with its corporate headquarters on Valley View Lane in Irving, inside the Dallas metroplex. Its mission critical page describes data centre scopes covering cable tray and feeders from medium voltage transformers to E-houses, chiller yards and generators, plus medium voltage service distribution and the installation of 2MW generators and 1MW UPS systems. It also runs a modular prefabrication operation in Irving and holds Texas licence TECL 40545.
Clark Electric is a commercial and industrial electrical contractor and engineering firm that has worked in the Dallas-Fort Worth area since 1984. Its critical power work covers uninterruptible power supply and generator installation and maintenance, switchgear installation, transformer installation, low and medium voltage cable and equipment, and ground resistance testing and correction. It is a Texas registered engineering firm, F-15824, and holds electrical licence TECL 18622. The site does not claim data centre projects, so it is recorded here for critical power work only.
Specialty contractor trading since 1925 with its office on Northside Parkway in Atlanta. Its electrical construction group procures, installs, tests and maintains electrical systems for commercial, industrial, healthcare, power generation and mission critical clients, and it also runs field service and testing. Its own testimonials page carries references from a data centre operator and from a substation project coordinated with Georgia Power.
Continental Electrical Construction Company, which trades as CECCo, is an electrical contractor with its headquarters in Oak Brook, Illinois, a downtown office on West Van Buren Street in Chicago and a warehouse in Bellwood. It has delivered data centre projects including an adaptive reuse build of more than 85,000 square feet over a 27 month programme. Its electrical scope covers UPS systems and generators, power distribution and branch circuitry, and structured cabling.
Corbins is an industrial electrical contractor founded in 1975 with its Arizona office on South 38th Street in Phoenix and further offices in New Mexico, Texas and Nevada. It states that it specialises in the design, installation and buildout of mission critical facilities including data centres and semiconductor plants, and its own articles describe energisation control, commissioning and medium voltage work on data centre sites.
Cummings Electrical is a Texas electrical contractor whose DFW headquarters is on Trinity Boulevard in Fort Worth, with further offices in Waxahachie and Arlington. Its mission critical data centre case studies include a financial data centre in Dallas using medium voltage Main-Tie-Main switchgear, ten backup generators and six UPS systems, and a Midlothian data centre with 25kV switchgear lineups feeding 4000A distribution skids and 2750kW generators. The firm also builds e-houses, electrical skids and custom UL panels through its integrated manufacturing division.
Dubak Electrical Group is an industrial electrical contractor with its corporate headquarters in LaGrange, Illinois, and a manufacturing and training campus in LaGrange Park. Its mission critical line builds data centre electrical systems covering power distribution, back-up generators and uninterruptible power systems. It runs a modular division that prefabricates electrical equipment centres and modular data centres.
Dynalectric Arizona is the Arizona division of Dynalectric Company, part of EMCOR Group, operating from an office on East Peterson Avenue in Mesa. It states that over two thirds of its work is mission critical and that it has carried out data centre work for large internet, search, software and consumer electronics providers. Listed scopes include electrical distribution systems, backup power generation, battery and flywheel uninterruptible power systems, rack level power distribution and medium voltage cabling, splicing and termination.
Commercial electrical contractor operating in metro Atlanta since 1990, with its office at Lilburn in Gwinnett County. Its data centre scope covers full site electrical installation, overcurrent protection, duct bank installation for power and data cable, and redundant power using UPS units, power distribution units and generators. A 24 hour service department handles maintenance and callouts.
Egnite Electric is an electrical contractor based at Briercroft Court in Carrollton, serving North Texas and the Dallas-Fort Worth metroplex. Its stated experience covers commercial fit-outs and tenant improvements, semiconductor facilities, data centres, airports and industrial projects. For mission critical facilities it handles power distribution, critical infrastructure wiring, backup power systems, redundant distribution and preventative maintenance.
Facility Solutions Group runs its Dallas electrical branch at 2525 Walnut Hill Lane in Dallas and covers Dallas, Tarrant, Collin and Denton counties. The Dallas operation states experience in data centre electrical construction and infrastructure, and offers commercial generator installation and emergency power systems for facilities across the metroplex. Work spans shell and core, fit-out and design-build electrical construction.
Gibson Electric is an electrical and technology contractor with its office at 3100 Woodcreek Drive, Downers Grove, Illinois, working across the Chicago area. It delivered the electrical construction for the first phase of the T5 Data Centers campus in Elk Grove Village, installing two 2.5 MW generators and four 1 MW uninterruptible power supplies. Its mission critical work covers electrical distribution systems, switchgear and data centre cabling.
Gurtz Electric is an electrical contractor headquartered at 77 West Seegers Road, Arlington Heights, Illinois, with two further offices in Wisconsin. It installs building power and distribution systems including distribution panels, transformers, generators, uninterruptible power supply and switchgear, and names high tech data centres and computer rooms among its service lines. Its published project list includes a hyperscale data centre in Illinois.
Electrical contractor founded in 1954 and based at Mableton in the Atlanta metro area. Its data centre work covers diesel generators and fuel systems, generator switchgear, utility paralleling, medium and low voltage switchgear, UPS systems, PDUs and structured cabling. It also holds facility maintenance contracts for data centres and other sites that run continuously.
Kelso-Burnett is an employee-owned electrical, communications and life safety contractor operating in Illinois since 1908. It runs offices in Rolling Meadows, the Chicago Loop, Gurnee and Rockford, plus one in Wisconsin. Data centres are one of the markets it lists on its own site, alongside commercial, industrial, healthcare and renewable energy work.
Commercial electrical contractor based at DeFoors Ferry Road in Atlanta. It names data centres and critical power as two of the four sectors it works in, alongside corporate interiors and medical, and its critical power page covers critical and standby power systems. Services span construction, design-build, prefabrication and a 24 hour service line.
Electrical contractor whose branch list names an Atlanta office at Riverside Parkway in Austell, Georgia, with its home office in Jacksonville, Florida. Its published account of work for the colocation operator Flexential covers data centre white space fit-outs, raised floors, cabling, renovations and ongoing maintenance at five Atlanta sites. The relationship started with a new data centre built in Atlanta.
New Phase Electrical is a critical power contractor with its address on West Pinnacle Peak Road in Phoenix, licensed under ROC 348619. It works only on critical power systems, covering uninterruptible power supply systems and bypass, generators, DC power plants, stationary battery strings and preventive maintenance, for data centres, hospitals and telecom sites. It states a primary concentration in the Phoenix metro with statewide coverage.
Industrial contractor based at Covington, Georgia, inside the Atlanta metro area, with an electrical and controls division that works on data centre projects. Its stated data centre scope covers temporary and permanent site power and distribution, grounding and infrastructure tie-ins, transformer and equipment coordination, site control panels and fibre installation. Rigging, structural steel and automation sit outside the electrical division.
REX Electric and Technologies is an electrical contractor with its office at 10 South Wacker Drive in Chicago. Its electrical construction services include switchgear installations, riser feeders, power and control wiring, mission critical data centres and UPS systems. It also keeps in-house teams inside large data centre facilities to manage and upgrade electrical and cabling infrastructure.
Rosendin is an employee-owned electrical contractor that runs its Arizona work out of a Tempe office. It is the electrical contractor on the MAZ Mesa data centre in Mesa, a design-build project delivered with general contractor DPR Construction. Data centres are one of the market sectors it lists.
Walker Engineering is an electrical contracting and technology services firm with its headquarters on West Walnut Hill Lane in Irving, and Dallas/Fort Worth is one of its four Texas markets. Mission critical is listed among its major markets, and its own project pages record data centre work at Garland and Richardson in the Dallas metro. The company holds Texas electrical licence TECL 17307 and operates a prefabrication shop in Irving.
Wilson Electric Services Corp is an electrical contractor with its main office in Tempe and further offices in Tucson, Sierra Vista, Albuquerque, Boise and Salt Lake City. Its data centre page describes Maricopa County projects covering 35kV medium voltage systems, underground duct bank, utility transformers, 2,285kW backup generators and 3000A reserve busway, plus a 12 MW Tier III facility in the Chandler technological corridor. It also lists generator, paralleling switchgear and uninterruptible power supply upgrades at a Phoenix area data centre it maintains.
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Common questions
Who owns the boundary with the high-voltage contractor?
Whoever your contract says, which is why it has to say. The usual flashpoints are the incoming cable terminations, the protection grading study and its relay settings, metering, and switching authorisation at energisation. Name one party for each in the scope matrix, and make the energisation sequence a joint deliverable with a single accountable signature.
What are the long-lead items in an electrical package?
Medium-voltage switchgear, power transformers, generator sets, uninterruptible power supplies, large low-voltage assemblies and busway are all made to order, and any of them can set your completion date. Get current quoted delivery in writing at tender rather than relying on the last project.
Can this work be done without an outage?
Usually yes, but only one side of a dual path at a time, under a permit issued by the operator's authorised person and a written switching programme. That needs a contractor holding the right switching authorisations and a current arc-flash assessment, plus programme allowance for night windows.
Should we buy the switchgear direct as owner-furnished equipment?
It can protect the programme when the order has to be placed before the contractor is appointed. It also moves risk: you carry delivery, transit damage and often warranty, and the installer will not stand behind equipment it did not procure. Freeze the load schedule first.
What does a lump sum usually exclude?
Read the exclusions before the number. Builder's work and fire stopping, temporary supplies, final connections to mechanical plant, containment for other trades, out-of-hours working, witness time for integrated systems testing, spares, and the as-built and asset register are the lines that most often return as variations.
What commissioning evidence should we ask for?
Test sheets tied to the level they were taken at: factory acceptance, site receipt, pre-functional, functional, then integrated systems testing with load banks. Ask specifically for secondary injection results against the issued protection settings, generator load acceptance and black-building results, UPS battery discharge results and transfer sequence records.
What the category covers, and where it stops
An electrical contractor on a critical-power site owns the path from the point of supply to the load: the medium-voltage switchgear and ring main units inside the site boundary, the transformers that step down to utilisation voltage, the low-voltage switchboards and distribution boards, the containment, cable and busway that carry power to the white space, the earthing and bonding system, and the standby side of generators, uninterruptible power supplies and transfer switches. The same contractor usually also installs small power and lighting and the final connections to mechanical plant.
Two boundaries decide how much of the programme you actually control. Upstream, the split with the high-voltage contractor and the network operator: who terminates the incoming cables, who owns the protection grading study, who holds switching authorisation at energisation, and who is liable if the relay settings are wrong. Downstream, the split with the mechanical trade: chillers, pumps and air handling units arrive with their own control panels and starters, so the contract has to say who supplies the local isolator, who lands the cable, who provides the interface to the building management system, and who proves the interlock. Write both boundaries into a scope matrix before tender.
The jobs you are actually buying
The work arrives in a few recognisable shapes. A new-build package runs from the intake substation to energised halls, usually split into a shell-and-core scope that lands the incoming supply, the main switchrooms and the standby plant, and a fit-out scope that populates the hall with remote power panels, busway runs, rack-level distribution and containment, released hall by hall as the operator takes capacity. A capacity upgrade adds a transformer, a generator or a UPS module into a frame that is already running, which turns an installation into a switching exercise. Remedial work is the third shape: a coordination problem to correct, a breaker frame the maker no longer supports, joints a thermographic survey has flagged.
The second axis is whether an outage is available, and on a live facility it usually is not. Work is then planned around the A and B paths: one side at a time, a written switching programme, a permit issued by the operator's authorised person, and a rule that nothing touches the remaining path. A firm competent on a greenfield hall may not hold the switching authorisations, the arc-flash assessment or the discipline to work beside a running load, and the operator will not grant access without them. Ask early, because the answer decides whether the programme is measured in weeks or in permitted night windows.
Distribution, cable, switchboards, earthing and standby
Power distribution and cable installation are the bulk of the labour. Distribution is the route: medium-voltage rings between switchrooms, transformer connections, low-voltage feeders to the main boards, busway down the hall and tap-off boxes at the rack rows. Cable installation is where the programme is won or lost, because containment has to be installed and surveyed before the first drum is pulled, and a route that clashes with pipework or steel gets discovered by a cable puller at the worst moment. Ask how pulls are planned: drum schedules, pulling-tension calculations on long runs, bending radii, segregation of clean and dirty circuits, and who records terminations.
Switchboard build, earthing and standby power are the specialist ends. Some contractors run their own panel shop and can build and verify low-voltage assemblies to IEC 61439-2 in house, which shortens the loop when a design change hits a board; others buy from an assembly maker and manage that interface. Earthing covers the electrode system, the main earthing terminal, bonding of structural steel and containment, and in a data hall a mesh bonding network, with resistance and continuity results an inspector will ask to see. Standby power covers generator installation with its fuel, exhaust and cooling interfaces, uninterruptible power supplies and their battery rooms, and the transfer equipment that decides how the load actually moves.
How this work gets priced, and what moves the number
There is no rate card for this, and be wary of anyone offering one. Critical-power electrical work is tendered against a drawing set, a specification and a programme: measured content in a bill or schedule of rates, a stated design portion if the contractor carries part of the design, preliminaries for site establishment, supervision and commissioning, and named sums for the equipment nobody can price blind. Most packages land as a lump sum whose exclusions and clarifications matter more than the headline figure. The form of contract decides what happens next: whether a delay is a compensation event with a defined process, or a claim you argue about for a year.
What moves the number is rarely the cable. It is the equipment: switchgear, transformers, generators and uninterruptible power supplies, quoted with a short validity period and often an escalation clause tied to copper and to the maker's order book. It is labour density, because a compressed programme puts more operatives on the same floor plate, with night and weekend premium to work beside a live load. And it is the commissioning allowance, under-priced more often than any other line. Read the exclusions: builder's work, fire stopping, temporary supplies, final connections to mechanical plant, witness time for integrated systems testing, and the as-built and maintenance deliverables all tend to sit in nobody's scope.
Certification, competence and the record you keep
The installation has to be certified against the wiring regime that applies where you are building: BS 7671 in the United Kingdom, the IEC 60364 family across much of Europe and Asia, the National Electrical Code in the United States, AS/NZS 3000 in Australia. Ask to see a sample of that paper trail before you appoint: installation certificates, schedules of inspection and test results, and the name of the qualified supervisor who signs them. Competence is separate: ask which named individuals hold switching authorisations for the voltages on site, who is appointed as authorised person, whether the arc-flash study has been done, and whether operative training matches the energy levels they will stand in front of.
The assemblies carry their own evidence: type-test and design verification certificates for low-voltage boards, short-circuit withstand, arc-fault containment classification where the specification calls for it, and factory acceptance test reports witnessed before anything ships. At handover you want more than a lever-arch file: as-built drawings that match what is installed, cable and circuit schedules, torque and termination records, protection relay setting files as loaded, test sheets tied to the commissioning level they were taken at, and maintenance information written for the people who will run the building. Agree the format and the deadline in the contract.
Where these projects actually go wrong
Scope gaps at the boundary between trades are the most common failure and often the most expensive. The classic is a mechanical package that supplies a control panel but not its isolator, or an air handling unit delivered with a flying lead nobody allowed containment for. The electrical contractor prices the electrical drawings, the mechanical contractor prices the mechanical schedule, and the gap surfaces on site as a variation, an argument about attendance and a fortnight of nobody doing the work. The same happens upstream, where the high-voltage contractor and the electrical contractor each assume the other owns cable terminations or the grading study. The fix is unglamorous: a scope matrix issued with the tender, line by line, with one named party accountable for each interface.
Switchgear lead times drive the whole programme, and are not a detail to resolve later. Medium-voltage switchgear, large transformers, generators and uninterruptible power supplies are made to order, and quoted delivery has been stretched and volatile since demand from this sector outran factory capacity. Re-confirm quoted delivery at tender rather than trusting a figure from the last job. If the equipment sits on the critical path, decide whether to place an early works order, buy direct and supply it as owner-furnished equipment, or accept a completion date set by a factory slot. Each choice moves risk: owner-furnishing usually moves delivery and warranty risk onto you, and an early order against an unfrozen design is how you end up with a board that does not match the final load schedule.
Commissioning finds design faults late, which means it finds them when they are expensive. Protection coordination that looks correct in the study fails secondary injection. A generator meets its load steps individually, then trips during a black-building test because block load and cooling plant were never modelled together. A transfer sequence works on paper and drops a hall because a timer was set from a template. That is why the commissioning regime matters more than the installation rate: pre-functional checks, functional testing, then an integrated systems test with load banks that exercises the failure modes the design claims to survive. Programme it with real duration, staff it with someone who has run one, and resist compressing it into the gap left by earlier slippage.
How to shortlist
Start with references of the same shape, not the same value. A contractor that has fitted out a hall beside a running load is a different animal from one that has wired a large office at the same contract sum. Ask for the last three critical-power projects, who the operator was, what the scope split was and who commissioned them. Then test capacity rather than claims: how much labour is directly employed against agency, whether there is a panel shop or a standing arrangement with an assembly maker, and who the named commissioning manager would be. A firm that cannot name the people is offering you a logo.
Then test the parts that bite. Does the firm hold the licence or registration the jurisdiction requires, and hold it where you are building rather than in its head-office country. Can it place a switchgear order and carry the deposit, and does it have a standing frame with an equipment maker or only a cold enquiry. Will it accept the design portion you intend to pass down, and has it read the scope matrix or only the drawings. How many operatives is it already committed to elsewhere in the same labour market, because that answers whether it can resource yours.
Why location changes the answer
Location decides more of this than the technical scope does. The connection date offered by the utility or network operator sets the earliest possible energisation, and in the constrained load centres that queue is counted in years rather than months, which pushes the design towards temporary supply, larger on-site generation or a phased release. The wiring and safety regime changes at the border, and so does licensing: some jurisdictions require a registered contractor or a nominated supervising engineer above a stated capacity, others a specific appointment for a privately owned high-voltage intake. A firm properly qualified one border away may not be entitled to sign your certificate.
Then there is the physical problem of getting plant to site. Transformers, medium-voltage panels and generator sets are abnormal loads: they need a route survey, escorts, sometimes a road closure, and a crane pad the structure can take. If the equipment is imported, add the port, the customs entry and the risk that a panel found damaged on offloading has a replacement lead time counted in months. Labour is the other local variable: where several large programmes build at once, the crews with real critical-power experience are already committed.