Panel & service upgrades
Commercial Panel & Service Upgrades
For Phoenix-area buildings that have run out of service capacity, breaker spaces, or both.
A panelboard swap and a service upgrade are different jobs carrying different risk. One is a permit and a few days. The other is a utility application, service equipment the utility must approve before it can be built, an inspection APS or SRP runs on top of the city's, and an outage somebody has to schedule. This page is about what sets the cost and the calendar on both.
Three different jobs that all get called a panel upgrade
These calls start the same few ways: a tenant wants equipment the panel has no room for, an inspector wrote a correction, or a breaker failed and nobody stocks a replacement. What the job becomes depends on whether the service still has capacity.
- Panelboard replacement. Same service, same feeder, new bus and breakers. Cheapest, and the only version that never involves the utility.
- Added distribution. The service stays; a subpanel or dry-type transformer picks up the new load out of spare capacity. Right when the building has headroom but nowhere left to land a circuit.
- Service upgrade. New service conductors, service equipment and metering, often a new utility transformer and pad. A utility application, a utility equipment review, and an energization date you only partly control.
- Obsolete gear replacement. The rating is fine; the breakers went out of production decades ago and the bus will not take anything currently made.
Classify it before it goes into a schedule. A panelboard swap is a permit and a few days. A service upgrade carries utility engineering, equipment that cannot be built until the utility approves the submittal, and a cutover date the utility owns.
Proving the load: NEC Article 220 and the 220.87 method
Nothing gets ordered until the load is proved. New buildings calculate from connected load under Article 220. Existing buildings are usually better served by measuring, and NEC 220.87 is the section that allows it.
220.87 permits the existing load to be taken from maximum demand data for a one-year period. Without a year of data, the fallback is maximum demand recorded continuously over at least 30 days with a recording ammeter or power meter on the highest loaded phase, while the building is occupied. Either way the test is the same: existing maximum demand at 125 percent, plus the new load, must not exceed the feeder ampacity or the service rating.
The month you record in decides the answer. A 30-day recording taken in a Phoenix January misses the cooling peak and shows capacity the building does not have in July. 220.87 requires the recording to account for the larger of the heating or cooling equipment load, by measurement or by calculation.
| What we need | Why it decides something |
|---|---|
| Twelve months of utility demand data | The cleanest path to 220.87 — your APS or SRP account already holds it. |
| Panel schedules and the existing one-line | What is connected now, not what the drawings claimed twenty years ago. |
| Nameplate data for the new equipment | Rooftop units, kitchen, chargers, process loads. Nameplate amps, not catalog numbers. |
The wire ampacity, voltage drop and transformer sizing calculators here are the ones we use in-house, and the panel schedule tool gives a schedule clean enough for a plan reviewer.
The utility application is the long pole
Both Valley utilities work the same way at the top: you apply, they engineer, they review your service equipment drawings, they inspect, and only their own employees energize. What differs is the paperwork and the money.
- APS applications go through build.aps.com. ESRM Section 200 sets the contents: applicant and property owner, address and legal description, structure type and square footage, plans showing the proposed meter location, estimated loads with voltage and phase, and credit information.
- Above 200 amps, metering is CT-rated at both utilities. APS requires EUSERC-approved test blocks at 200 A and below and CT-rated enclosures above it (ESRM 302.9). SRP's socket ratings are 100, 200 and 400 A, and the 400 A Class 320 socket is residential only.
- The gear cannot be built until the utility approves the submittal. APS reviews every commercial meter enclosure before manufacture — one-lines showing the neutral-to-ground bond link, EUSERC page references, ampacity, dimensions, voltage, phase, bus bracing, padlockable provisions on every service disconnect. SRP wants shop drawings above 225 A in ESS Section 1 and above 400 A in Section 9; we submit at the lower threshold.
- Two inspections, not one. APS inspects the service entrance equipment in addition to the AHJ, and the contractor initiates it twice: when the equipment lands, and again after corrections. APS also rejects meter locations without three feet of clear working space at the panel face.
- The money works differently. APS line extensions run on ACC Service Schedule 3 — all costs paid in advance, refundable over a five-year feasibility window, no interest. SRP's contribution in aid of construction is generally non-refundable. SRP stopped permitting customer-owned service after 6 July 2026.
Do not assume the utility from the address. SRP's own city list is served "all or in part," and the boundary runs through neighborhoods. Downtown Mesa is a third case: the city runs its own electric utility over roughly 5.5 square miles of the core. Read the utility name off a current bill.
Code: which edition, and what changed since the gear was built
Arizona has no statewide building or electrical code. A.R.S. Title 9 lets each city adopt by reference and A.R.S. 11-861 lets the county do the same for unincorporated areas, so two buildings four miles apart can sit on different NEC cycles. The existing installation was legal under an older edition; the new work will not be judged against it.
| Jurisdiction | NEC edition | Effective |
|---|---|---|
| Phoenix | 2023 | 1 Aug 2025, Ord. G-7397 |
| Unincorporated Maricopa County | 2017 | Adopted 17 Aug 2022 |
| Scottsdale | 2020 | 1 Jan 2023 |
| Queen Creek | 2020 | 1 Jan 2023 |
| Buckeye | 2023 | 1 Jan 2025 |
| Chandler | 2023 | 1 Jul 2025, Ord. 5108 |
| Surprise | 2023 | 1 Jan 2026, Ord. 2025-14 |
| Avondale | 2023 | 1 Jan 2026 |
| Mesa | 2023 | 8 Jan 2026 |
| Glendale | 2023 | 9 Jan 2026 |
| Goodyear | 2023 | 23 Jun 2026 |
The edition is half of it. These are what bite on a Valley service upgrade:
- Available fault current. A bigger utility transformer raises it. NEC 110.24 requires service equipment in other than dwellings to be field marked with the maximum available fault current and the date, and recalculated when a modification affects it. Gear you meant to keep at 10 kAIC can end up inside the project, so we run the study.
- Arc energy reduction. Where a breaker is rated or can be adjusted to 1,200 A or more, NEC 240.87 requires arc energy reduction; 240.67 covers fuses. A real line item on new main gear.
- The six-disconnect rule changed. The 2020 and 2023 NEC put two to six service disconnects in separate enclosures or barriered compartments — not six handles in one panelboard, which the 2017 edition allowed.
- EMT alone is not an equipment grounding conductor here. Phoenix, unincorporated Maricopa County and Glendale each amend NEC 250.118(4) to require a wire-type EGC as well; Phoenix and Glendale amend 334.10 to keep NM cable out of commercial buildings.
- Working space. New gear is deeper than what it replaces, the 110.26 clearances still apply, and a 1970s electrical room rarely gives them up without moving a wall.
The permit is a separate electrical trade permit, filed in Phoenix through SHAPE PHX. Phoenix's July 2026 commercial plan review averaged 30 days on major projects and 33 on both medium and minor ones, so a small scope is not a fast review, and plan review costs 80 percent of the permit fee above $50,000 of valuation. In unincorporated Maricopa County the line is 200 amps: like-for-like work up to 200 A is a non-technical permit issued in one to two business days, while an upgrade above 200 A goes to technical review with a site plan.
The outage, and how it gets kept short
Every service upgrade contains a moment when the building is dark. The rest of the job exists to make that moment short, scheduled and boring.
- Survey and load data first. Meter the existing service, confirm the serving utility, establish the available fault current.
- Utility application and equipment submittal in parallel. One starts the utility's engineering, the other has to clear before the gear can be built. In sequence they add weeks for no reason.
- Permit and plan review, carrying the one-line, the load calculations and the fault current calculations.
- Build everything that can be built live. Conduit, gear set and terminated, feeders landed at one end, grounding and bonding complete, temporary power standing by if the tenant can take no outage.
- The cutover window. Utility crew, our crew, the AHJ inspection and the utility's inspection all land inside it. Only utility employees energize, so the window is theirs and it is booked in advance.
- Re-terminate, test, energize, label. Fault current marking updated per 110.24, panel schedules corrected to what is in the panel, arc flash labels updated where a study exists.
A daytime cutover is cheaper than a night or weekend one, and not only in labor. Phoenix charges $195 an hour for inspections outside its inspection hours — two-hour minimum just outside them, three hours on weekends and holidays — plus $195 for each re-inspection after the first. Our crews work Monday to Thursday, 6:00 AM to 3:00 PM, and Friday to 2:00 PM.
Two Phoenix items belong in the schedule early: the commercial temporary power application, and the Electrical Utility Clearance Only permit required before the utility will re-energize a service dormant more than six months.
Where we are a bad fit
- Scheduled, permitted work. A same-day trouble call or an unscheduled call-out is a dispatch job, and we are not a dispatch operation.
- We will not quote a utility date the utility has not given. APS publishes no committed timeline for commercial new service. Anyone quoting weeks before an application exists is guessing with your schedule.
- We will not price gear lead time off a website. We take a quoted lead time from the manufacturer at bid and put that date in the proposal, because that date usually sets the finish.
- We do not stamp drawings in-house. Where a sealed design is required we coordinate a licensed Arizona PE. See engineering and design-build.
- No overnight emergency board. This is scheduled, permitted work.
Send the one-line, the panel schedules and twelve months of demand data with the bid request, and name the jurisdiction. We will tell you which of the four jobs at the top of this page you have before anyone talks about price.
Frequently asked questions
How long does a commercial service upgrade take in Phoenix?
Longer than the electrical work itself, and the utility usually sets the date. APS publishes no committed timeline for commercial new service; its own construction pages say only that timelines vary by job complexity and current turnaround. On the city side, Phoenix reported an average commercial plan review of 30 days for major projects and 33 days for both medium and minor projects in July 2026. The item that most often decides the finish date is the service equipment itself, because an APS commercial meter enclosure has to be reviewed and approved by APS before it can be manufactured. A realistic schedule runs the utility application, the equipment submittal and the building permit in parallel, and treats the manufacturer's quoted lead time as the critical path.
Can you size the new service from our existing utility bills?
Often, yes, and it is usually the more defensible method. NEC 220.87 lets the existing load be established from the maximum demand data for a one-year period, which your APS or SRP account already holds. Where a full year is not available, the code accepts maximum demand recorded continuously over at least 30 days with a recording ammeter or power meter on the highest loaded phase while the building is occupied. The test is then that the existing maximum demand at 125 percent, plus the new load, does not exceed the ampacity of the feeder or the rating of the service. In Phoenix the recording has to account for the cooling load, by measurement or by calculation, or a winter recording will overstate the capacity you have in July.
Does the whole building have to shut down?
Only for the cutover window, and often only part of the building even then. Most of a service upgrade is built while the existing service runs: new conduit, gear set and terminated, feeders pulled and landed at one end, grounding and bonding complete. What cannot be done live is the final transfer, because the utility has to disconnect and reconnect and only utility employees energize a service. Where a tenant can take no outage at all, the usual answers are temporary power for the duration or a staged transfer that moves loads to the new gear in groups. Both cost money and both need deciding at bid time rather than on the day.
We are going from 200 to 400 amps. Can we keep the meter socket?
No. Both Valley utilities draw the line at 200 amps for commercial service. APS requires EUSERC-approved test block and bypass provisions on self-contained commercial services 200 amps and below, and EUSERC-approved CT-rated meter enclosures on all commercial sites above 200 amps. SRP's accepted meter socket ratings are 100, 200 and 400 amps, and the 400 amp Class 320 socket is residential only, so commercial work above 200 amps is CT-rated at SRP as well. Plan on a CT cabinet, and on the submittal review that has to clear before the equipment can be manufactured.
Do I need a permit to replace a panelboard like for like?
Yes. Commercial electrical work is a separate trade permit in Phoenix, filed through the SHAPE PHX portal. In unincorporated Maricopa County the distinction that matters is amperage: like-for-like replacements and clearances up to 200 amps are handled as non-technical permits issued in one to two business days, while a service upgrade above 200 amps goes to technical review and requires a site plan. Other Valley cities each run their own portal, fee schedule and amendments, which is why we confirm the jurisdiction before quoting the permitting effort.
Which NEC edition applies to my building?
Whichever one your jurisdiction adopted, because Arizona has no statewide building or electrical code. Phoenix has enforced the 2023 NEC since 1 August 2025 under Ordinance G-7397. Unincorporated Maricopa County is still on the 2017 NEC. Scottsdale and Queen Creek are on the 2020 NEC. Mesa, Chandler, Glendale, Surprise, Avondale, Goodyear and Buckeye are on the 2023 NEC, with effective dates ranging from January 2025 to June 2026. For Gilbert, Peoria and Tempe, confirm the current edition directly with that city's building department before design. We could not verify those three to our own standard, and we would rather say so than publish an edition you might design to.
Who actually turns the power back on?
The utility, and nobody else. Both APS and SRP reserve energizing to their own employees, and they do it only after the authority having jurisdiction has issued its electrical clearance. On the APS side there is an extra step people forget: APS runs its own inspection of the service entrance equipment in addition to the city or county inspection, and the contractor has to initiate it twice, once when the equipment arrives on site and again after any corrections are made. Scheduling those inspections late is one of the most common ways a cutover date slips.
Get a price on this scope
Ready to price your Phoenix project?
Send us the plans, the scope, or just the problem. We will tell you what it takes. Call (602) 396-5216 or request a bid online.