Before you sign a lease for a shop, warehouse or kitchen, find out the building's service voltage, whether it's single-phase or three-phase, and how many amps it can deliver, then compare that with the nameplates on the equipment you plan to run. If the building comes up short, the fix may be a utility service upgrade that the utility designs, prices and schedules, so it pays to know before the lease is signed, not after the machines arrive.
This article is for business owners in Los Angeles, Orange and Ventura counties moving CNC machines, air compressors, welders, commercial kitchen equipment or fleet EV chargers into a leased space.
Single-phase and three-phase, in plain English
Single-phase power is what most homes and many small storefronts get: two hot wires and a neutral. It runs lights, outlets and smaller equipment well.
Three-phase power uses three hot wires, each carrying alternating current timed a third of a cycle apart from the others, so power flows more steadily. Much of the larger motor-driven equipment in shops, from compressors to machine tools, is built to run on it, and some of it is sold only in three-phase versions.
The voltages you'll hear about
Southern California Edison's guide for electricians installing commercial EV charging lists typical commercial voltage levels, among them 120/240 volts single-phase and 120/208 volts and 277/480 volts three-phase. LADWP's power quality standards list 120, 208, 240, 277 and 480 volts among its nominal service voltages.
What the numbers mean for a tenant:
- 120/240 V single-phase: common in older small buildings and some storefronts. Fine for lighting and plug loads; limited for big three-phase machines.
- 120/208 V three-phase: common in offices, retail and mixed-use buildings. Many machines and kitchen appliances are offered in 208 V versions.
- 277/480 V three-phase: found in many larger industrial and warehouse buildings, where 480 V feeds big motors and 277 V can feed lighting.
A machine rated 230 or 240 V may not run correctly on 208 V, and 480 V equipment needs a transformer to run from a 208 V service. The voltage on the nameplate has to match what the building has, or be reachable with the right equipment.
How to check before you sign
1. Ask the landlord or broker in writing
Ask for the service size in amps, the voltage and the phase, and whether the space has its own meter and panel or shares a service with other units. Ask too whether any other tenant already uses most of that capacity. A listing that says "heavy power" or "industrial power" isn't an answer; ask for the numbers.
2. Leave the electrical room to the professionals
You don't need to inspect the switchboard yourself to get these answers, and you shouldn't try. Ask the landlord's building engineer or property manager for the ratings on record, or for any electrical drawings of the building, and let a licensed electrician confirm them on site.
Don't open switchboard doors, panel covers or deadfronts, and don't step into an electrical room to look around. Commercial switchboards, whether 208 V or 480 V, can produce a dangerous arc flash, and checking them is a job for a licensed electrician wearing the right protective equipment.
3. Collect your equipment's specs
For every machine you plan to bring, write down the voltage, phase, full-load amps or kW, and any note about required circuit protection, from the nameplate or the manufacturer's spec sheet. Include the things that are easy to forget: the compressor, the dust collector, the walk-in cooler, the hood fans and any EV chargers for company vehicles.
That list is what an electrician uses to calculate the load and see whether the building can carry it.
4. Have a licensed electrician evaluate the site
A site evaluation compares the existing service and distribution with your equipment list: available voltage and phase, spare capacity, panel space, the distance from the service to where the machines will sit, and whether a transformer or a new panel or subpanel is needed. Schedule it before signing, while the lease terms can still change.
If the building doesn't have what you need
A new or larger service from the utility
When a building lacks three-phase power or enough capacity, the utility decides how to serve the new load. Costs, design and timing come from the utility, and they vary with the site.
- SCE: its project request page is where new service and upgrades for commercial properties start. SCE's published roadmap for new or upgraded service lists project intake, then engineering and design by SCE, then the customer's payment and contracts before construction and energizing. SCE also publishes average and maximum times for its own steps; your SCE representative can tell you what applies to your site.
- LADWP: its electric services FAQ sends services larger than 400 amps, or three-phase, to its Construction and Renovation electric service request process. For underground service, the same FAQ says to contact the Electric Service Representative for your address to check feasibility, that plans should include a site plan, load schedule and one-line drawing, and to allow six to eight weeks for a Service Planning Engineer to determine exact installation costs.
- City-owned utilities such as Burbank, Glendale, Pasadena and Anaheim run their own service processes.
For larger projects, SCE's building expansions and new facilities page describes scoping meetings, job walks and a review meeting where the customer learns anticipated costs and timelines.
On the building side, a new service usually means new service equipment, feeders and panels, with the city or county electrical permit and inspections coordinated as part of the work.
Phase converters for some motor loads
A rotary phase converter or a variable frequency drive (VFD) can run some three-phase motors from single-phase power. Both have limits.
- Rotary converters are sized to the machine's horsepower or amps, voltage and load type. American Rotary, a converter maker, notes that loads differ in their starting demands and that sizing should account for them.
- VFDs with three-phase input can often run on single-phase power if they are derated; Precision Electric, a drive service company, advises confirming that with the drive's manufacturer.
Some equipment manufacturers don't allow a converter at all or set conditions for one. Ask the machine's manufacturer before you rely on a converter, and get the answer in writing.
Choosing equipment for the power you have
Sometimes the simplest path is equipment built for the available power: a 208 V three-phase model instead of a 480 V one, a single-phase compressor, or a smaller kitchen line. That only works when the building has the capacity, which the load calculation shows.
Lease points to raise
General questions to settle with the landlord before you sign, with your own attorney or broker reviewing the terms:
- Who pays for a new service, panel, feeders or transformers, and does the work stay with the building?
- Does the landlord have to approve electrical work, and how long does that approval take?
- Will the rent start before the power you need is available?
- Can you end or adjust the lease if the utility says it can't serve your load at that address?
- Is the capacity you're counting on reserved for you, or shared with other tenants?
What Infinity Electrical does
Infinity Electrical Inc. (CSLB #1100231) does three-phase electrical work for businesses across Los Angeles, Orange and Ventura counties: site evaluations and load calculations before a lease, panels, subpanels and feeders, and dedicated circuits for machinery, compressors and kitchen equipment. When a project needs a new or larger service, we coordinate the utility steps with you; the utility designs and builds its own side. Our commercial electrical page covers what we do for business properties.
Shops in industrial areas like the Nordhoff corridor in Chatsworth (LADWP) and the light-industrial buildings of Torrance (SCE) deal with different utilities, so the first step on any site is finding out who serves it.
FAQ
How can I tell if a building has three-phase power?
Ask the landlord for the service voltage, phase and amps in writing, then have a licensed electrician confirm it on site. Don't open switchboard doors or panel covers to check for yourself.
Is 208 volts the same as 240 volts?
No. A 120/208 V service is three-phase, while 120/240 V is usually single-phase. Equipment rated for one may run poorly or not at all on the other, so check the nameplate and the manufacturer's instructions.
Can I run a CNC machine or compressor on single-phase power?
Sometimes, with a rotary phase converter or a derated VFD, within the limits the converter and machine manufacturers set. Some machines aren't approved for it, so ask the manufacturer first.
Who pays to bring three-phase power into a leased building?
That depends on the utility's charges and on what you and the landlord agree in the lease. The utility prices its own work after it designs the service, so ask early and build that unknown into the lease terms.
How long does a utility service upgrade take?
It depends on the utility, the site and how quickly each side supplies what's needed. For underground service, LADWP says to allow six to eight weeks just for its engineer to determine costs, and SCE publishes average and maximum times for the steps it controls, so start the conversation early.
Before you sign
Send us the address, the landlord's power details if you have them and your equipment list through the estimate form, or call (844) 430-7681. Free estimates on eligible work, and the scope and price come in writing before any work starts.