How to Set Up Temporary Construction Power
Updated August 29, 2026 • Written by the field team at Arizona Electrical Solutions. All field guides →
Temporary power is the first electrical work on every project and the first thing that can stall one: no temp service, no saw cuts, no pumps, no schedule. It's also genuinely dangerous work when treated casually — construction sites combine damaged cords, standing water, metal scaffolds, and workers of every trade using whatever receptacle is closest. NEC Article 590 and OSHA's construction rules exist because that combination kills people, and both are enforced on Tucson jobsites.
The rule of Article 590 that surprises newcomers is what it doesn't relax: temporary wiring follows the whole code except where 590 specifically says otherwise. The relaxations are narrow — some open wiring, boxless splices on cord in certain cases — and the additions are strict, GFCI protection above all.
In TEP territory the critical path runs through the utility, not the code book: the temp service application, pole spec, inspection, and release have lead times that don't compress. Our crews handle that sequence — see the TEP new service requirements walkthrough — and the guide below is the full setup in the order it actually happens.
We do this work. Arizona Electrical Solutions self-performs commercial electrical on commercial projects across Arizona. Temp power that's up before the schedule needs it — TEP coordination, inspection, and maintenance through closeout included.
Safety first. This work is for qualified, licensed electricians only. Temporary installations see the harshest duty on any site — traffic, weather, water, and every trade's abuse — so inspect before every use, and de-energize, lock out, and verify absence of voltage before working on any part of the system. GFCI protection required by NEC 590.6 and OSHA 29 CFR 1926.404 is never optional and never to be bypassed. Temporary services require permits, inspection, and a utility release; the locally adopted NEC edition and local amendments govern — confirm with your AHJ.
What you'll need
- Current NEC codebook or code app (2023 numbering used here) — Article 590; OSHA 29 CFR 1926 Subpart K
- Utility temp service application and spec sheet — pole height, clearances, meter socket, point of attachment
- Class 3 or better treated pole, or a listed temporary power pedestal, with rain-tight service equipment
- Meter socket, main breaker enclosure, and GFCI-protected receptacle assemblies, all listed and rain-tight
- Ground rods, clamps, and grounding electrode conductor per 250.66
- Extra-hard-usage flexible cords (type W, SOOW or per the listing) for feeders and heavy circuits
- Portable distribution centers ('spider boxes') with GFCI protection, listed for the purpose
- Guarded lamp strings or LED temporary lighting listed for wet locations
- Cord ramps, hangers, and elevation hardware to keep cords out of traffic and water
- GFCI tester and a receptacle tester — used weekly, not once
Code references
| NEC 590.2 | Temporary wiring follows the full code except as specifically modified by Article 590. |
| NEC 590.3(D) | Temporary wiring removed immediately upon completion of construction. |
| NEC 590.4 | Feeders, branch circuits, receptacles, lighting guards, boxes, and protection from damage for temporary installations. |
| NEC 590.6(A) | GFCI protection for all 125V, 1Ø, 15/20/30 A receptacles in use by personnel. |
| NEC 590.6(B) | Other receptacles: GFCI protection or the assured equipment grounding conductor program. |
| OSHA 29 CFR 1926.404(b)(1) | Federal construction rule requiring GFCIs or an assured grounding program on site. |
| NEC 250.66 | Grounding electrode conductor sizing at the temporary service — same table as permanent work. |
| NEC 250.24 | Service grounding and the single neutral-to-enclosure bond at the temp service disconnect. |
| NEC 400.10 / Table 400.4 | Flexible cord uses and types — extra-hard-usage cords for jobsite duty. |
Section numbers follow the 2023 NEC; the edition adopted by your jurisdiction governs.
Step by Step
Set Up Temporary Construction Power — step by step
1. Plan the loads before the pole
List what the site actually needs powered and when: office and sanitary trailers, compaction and dewatering pumps, saws and rod benches, welders, the tower crane if there is one, and temporary lighting. Welders and cranes change the answer — a site that needs 480V three-phase for a crane or big welders is ordering a very different temp service than one running 120/240V hand tools.
Size the temp service from that list with honest diversity, and place the pole where the utility can reach it and the feeders can reach the work. Moving a temp pole mid-project because the building grew over it is a real and expensive change order — check the site logistics plan and the crane radius first.
2. Order the utility temp service early — it's the critical path
In TEP territory, submit the temporary construction service application as soon as the job is real. The utility controls transformer availability, the service drop or lateral, and the crew schedule that energizes you — none of which compress because the GC is in a hurry. Weeks of lead time is normal; plan the schedule around it rather than hoping.
Get the utility's temp service spec in writing and build to it exactly: pole class and setting depth, point of attachment height, clearances over drives and pads, meter socket model and height, and conductor sizes. The utility will not connect to a pole that misses their spec, and the re-inspection loop costs a week each time around.
3. Build the temp pole to spec
Set the pole plumb and to the utility's embedment depth, then hang the service: weatherhead and drip loops at the required clearance, meter socket at the specified height, main breaker in a rain-tight enclosure below it, and the receptacle assemblies below that. Everything listed, everything rain-tight, everything closed — a temp pole is outdoors for its whole life and monsoon season will find every open knockout.
Ground it like the service it is: ground rod(s) at the pole base, grounding electrode conductor sized per 250.66, and the neutral bonded at the service disconnect exactly once. The temp service follows the same Article 250 rules as a permanent one — 590 relaxes none of it.
4. Pass inspection, then get the utility release
The sequence is fixed: AHJ permit and inspection first, utility connection second. The inspector is looking at the same things this guide lists — clearances, grounding, GFCI protection, listed equipment, working space — and the utility won't energize without the release. Book the inspection the moment the pole is dressed; idle days between 'built' and 'energized' are pure schedule loss.
While you're waiting, walk the distribution plan with the GC's superintendent: where spider boxes land, which routes cords will take, what gets powered first. The plan that exists before energization is the one that keeps cords out of the crane path.
5. Distribute with listed gear, not a daisy chain
Feed portable distribution centers — spider boxes — with extra-hard-usage cord or a wiring method from Chapter 3, and put them where the work is: one per floor or zone beats one heroic cord run. Set them on blocks or hang them so they're out of the mud and standing water, and protect every feeder crossing a traffic path with ramps or by flying it overhead at the clearances 590.4 points to.
Branch circuits and receptacles follow 590.4: receptacles on their own circuits — not tapped off the temporary lighting, so a tripped saw doesn't drop the stairwell lights — boxes where the general rules require them, and cords protected from damage and pinch points. The daisy chain of power strips and household cords is exactly what this gear exists to replace.
6. GFCI everything — 590.6 and OSHA agree
All 125-volt, single-phase, 15-, 20-, and 30-ampere receptacles in use by personnel during construction, remodeling, or demolition must have GFCI protection for personnel — 590.6(A), with OSHA 1926.404(b)(1) enforcing the same outcome on every covered site. That includes the receptacles on the temp pole, the spider boxes, and cord sets; listed cord-set GFCIs cover equipment that isn't otherwise protected. Higher-voltage and higher-amperage receptacles used by personnel get GFCI or the assured equipment grounding conductor program per 590.6(B).
Monsoon season will make GFCIs trip, and the tripping is the system working: wet cords ends and flooded boxes are real faults waiting for a person. Fix the moisture, replace the damaged cord — never, ever bridge the GFCI. Test every device weekly with a tester, and after every storm.
7. Light it and maintain it
Temporary lighting gets guards on every lamp per 590.4(F) — or fully enclosed LED strings that don't need them — hung high enough to survive material handling, on circuits separate from receptacle power. Egress paths and stairs stay lit whenever workers are present; in practice that means lighting circuits arranged so one fault doesn't black out a stairwell.
Then maintain the whole system like the tool it is: damaged cords cut out of service immediately (not taped — removed and repaired properly or scrapped), enclosures kept closed against dust and rain, and a weekly walk of poles, boxes, and cords. Arizona adds its own duty cycle: UV-cooked cord jackets and 115°F enclosure interiors age gear fast, so shade what can be shaded and replace what's checked or brittle.
8. Remove it when construction ends — immediately
590.3(D) is blunt: temporary wiring shall be removed immediately upon completion of construction or the purpose for which it was installed. The spider box that stays behind 'for the punch list' and the cord through the ceiling that outlives the job are both violations — and both show up in fire reports. Plan the demob: temp comes down as permanent power districts energize, area by area.
The clean handoff is a dated walkdown with the GC: temp service released back to the utility, pole pulled or pedestal removed, cords and boxes inventoried and gone. It's the cheapest closeout item on the job and the one most often left dangling.
Watch Out
Common mistakes
- Ordering the utility temp service after mobilization instead of weeks before — the pole is cheap, the utility lead time is the schedule risk.
- Building the pole to habit instead of the utility's written spec, then losing a week per re-inspection loop.
- Tapping receptacles off the temporary lighting circuits, so one tripped tool drops the stairwell lights.
- Bridging or cheating a GFCI that keeps tripping instead of fixing the wet cord that's tripping it.
- Household-grade cords and power strips daisy-chained across a jobsite in place of extra-hard-usage cord and listed spider boxes.
- Cords run through door pinch points, standing water, and drive lanes with no ramps or elevation.
- Unguarded lamps at head height in stairwells and corridors.
- Leaving temp wiring energized after completion 'for convenience' — 590.3(D) says immediately, and orphaned temp wiring is a documented fire starter.
FAQ
Frequently asked questions
Who provides temporary power on a commercial job — the GC or the electrician?
Contractually it varies, but the install itself is licensed electrical work: the temp service, distribution, and lighting are permitted, inspected installations. The common arrangement is the electrical contractor building and maintaining temp power under its permit, with the GC paying the utility account. Sort out cord-and-tool responsibility in the subcontract — 'power to within 100 feet of the work' is the phrase that prevents most arguments.
How long does a TEP temporary construction service take?
Plan on weeks from application to energization, not days — the utility sequence of application, spec, field check, and crew scheduling has its own calendar, and monsoon-season storm restoration can push it. Submit the application as soon as the project is real, build the pole to the written spec, and have the AHJ inspection done the day the pole is dressed so the release is the only thing left.
Does temporary power need a permit and inspection?
Yes. A temporary construction service is a permitted electrical installation, inspected by the AHJ before the utility will connect, and Article 590 holds the installation to the full code except for its specific, narrow relaxations. Temporary never means uninspected.
What receptacles need GFCI protection on a construction site?
Every 125-volt, single-phase, 15-, 20-, and 30-amp receptacle in use by personnel — NEC 590.6(A), matched by OSHA 1926.404(b)(1). That covers the temp pole, spider boxes, and cord sets. Receptacles outside that description get GFCI protection or a written assured equipment grounding conductor program per 590.6(B). On our sites the answer is simpler: everything a worker plugs into is GFCI-protected.
Can we use the building's permanent wiring as temporary power?
Yes, and on larger projects it's the plan: energize permanent panels area by area and work off them, retiring cords as districts come live. It takes the AHJ's inspection of the permanent work being energized, the utility's release, and real lockout discipline — plus GFCI protection at the receptacles workers use, because 590.6 applies to receptacles used by personnel during construction regardless of whether the wiring is temporary or permanent.
What kind of cords are legal on a jobsite?
Extra-hard-usage cords — type W, SOOW, and similar per Table 400.4 — for the feeders and anything living in traffic; hard-usage cord is the floor for lighter duty per 590.4. Jacket type matters less than condition and routing: a perfect cord through a door pinch point is tomorrow's ground fault. Inspect before use, elevate or ramp every crossing, and cut damaged cords out of service on the spot.
Is a generator a substitute for a utility temp service?
For early sitework and remote scopes, often — a properly grounded and bonded generator with GFCI-protected outputs runs pumps and small tools fine, under the same Article 590 rules plus the generator grounding provisions of 250.34. For a full vertical build it rarely pencils: fuel, maintenance, noise, and the crane's appetite make the utility temp service cheaper within weeks. We typically bridge with generators only until the TEP release lands.
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