Temporary Power & Commercial Generators in Santa Clara County Construction Temp Power. Standby Generators. Transfer Switches.

Temporary power is a short-term electrical system installed only for the duration of a project to run tools, lighting, trailers, and equipment until permanent power is available. It can be supplied by a temporary utility service (temp power pole, meter, and distribution panel) or by portable generators feeding spider boxes and temporary panels. By code, temporary wiring is regulated under NEC Article 590, OSHA 29 CFR 1926.405, and California Title 8 Section 2405.1, and must be removed when the project is complete. All receptacles used by workers must have GFCI protection, and the setup must pass inspection before the utility will energize it. Temporary wiring is not a permanent solution. One rule gets misquoted constantly, including at inspection counters: the 90-day limit in Article 590 applies to holiday decorative lighting and similar purposes, not to construction. Construction temporary power is permitted for the whole period of construction, remodeling, repair, or demolition, however long that runs. If a schedule conversation on your job has been anchored on 90 days, that is worth correcting before it costs anyone a remobilization.

They solve opposite problems and the equipment is not interchangeable. Temp power exists because the permanent service does not yet, so it is a short-lived service built to run a job site and then removed: a temp pole or pedestal, a meter and disconnect, a temporary panel, and GFCI-protected distribution out to the trades. A standby generator exists because the permanent service can fail, so it is a permanent installation that sits idle behind listed transfer equipment and picks the building up when the utility drops. Temp power is usually fed from one source at a time and needs no transfer switch. A standby generator always needs transfer equipment so it cannot backfeed the utility. Different permits, different code basis, different lifespan. Our team carries both scopes, and on a phased project they overlap, because the temporary service has to stay alive until the permanent service is energized and inspected.

From the equipment list, never from square footage. Our team builds the temporary load from what the site will actually pull at peak: the hoist or crane, welding receptacles, compressors, temporary heat or dehumidification, pumps, the office and change trailers, and the task and egress lighting, then accounts for the trades that stack up in the middle of the schedule rather than the ones on site the first week. Most temporary services land at 100 or 200 amps single-phase, and step up to 400 amps or greater three-phase when the total or a hoist or large welder demands it. That break also changes the utility path: PG&E processes single-phase temporary service of 200 amps or less as an expedited "Express Connection," while three-phase at 400 amps or greater runs the full application (PG&E Electric and Gas Service Requirements, TD-7001M, Section 5). Undersizing shows up as nuisance trips and a service that has to be re-permitted and re-set mid-project, which costs far more than building it right the first time. Oversizing mostly costs money up front. We would rather have the equipment list and the schedule in hand and get it right once.

On our jobs, our team files both the electrical permit and the temporary service application with the serving utility (PG&E across most of Santa Clara County, Silicon Valley Power in the City of Santa Clara). The account itself is set up in the name of whoever is paying for construction power, usually the general contractor or the owner, so that billing detail comes from you. The general contractor owns the pole location and site access, and the utility owns everything on its side of the meter: the drop or lateral, the meter itself, and the energization. The AHJ owns the rough inspection and the release that tells the utility it may energize. The sequence only breaks when the utility application is opened after the inspection passes instead of alongside the permit, which is the most common reason a site sits dark with a crew already mobilized.

The temporary service stays live until the permanent service is energized and signed off, then the site is cut over on a scheduled outage and the temporary wiring is removed. Two things decide whether that goes smoothly. The first is location: if the temp pole was set in the path of the permanent service trench or the switchgear pad, it has to move mid-project, which is avoidable with a five-minute conversation at the start. The second is sequencing the permanent service application on its own track early, because that path involves the utility, plan check, and often gear with a real lead time. On a phased occupancy we walk loads onto the permanent panels in stages so finished areas can be turned over while the rest of the building still runs on temporary power. Removing the temporary installation is not optional housekeeping, it is required when the work it served is complete, and it is part of closing the permit.

Commercial generator sizing is based on measured load, not guesswork. The proper process measures peak amps on each leg of your service during normal operations, converts to kilowatts, and adds 25% reserve capacity for motor starting and growth. As a quick planning ballpark: typical commercial or office space needs approximately 50 kW plus 5 watts per square foot. Retail and restaurant spaces need approximately 50 kW plus 10 watts per square foot due to refrigeration and kitchen loads. These are planning estimates only. Cali Rollin Electric performs a formal load study and coordinates with life-safety requirements under NEC Articles 700, 701, 702, and 708 before recommending a specific kW rating. The right size depends on your actual connected loads, not square footage alone.

Yes. For both permanent and rental generators, best practice is three-way coordination among the electrical contractor, generator supplier, and for permanent units the engineer or GC. The supplier confirms fuel type, kW rating, voltage, and physical requirements including weight, footprint, exhaust, and clearances. Cali Rollin Electric designs and installs the electrical integration: pads, conduits, cabling, terminations, and transfer equipment. For rental generators we pre-plan connection points and cabling so the generator can be dropped in and connected rapidly during an outage. This coordination prevents sizing or compatibility mistakes and speeds up both installation and any future emergency deployments.

Yes, for any permanently installed generator that ties into a building's electrical system, a transfer switch is required by code to prevent dangerous backfeeding onto the utility grid. Emergency systems under NEC Article 700 and code-mandated standby systems under Article 701 (egress and exit lighting, fire pumps, and some medical loads) must use automatic transfer equipment so power is restored without operator intervention. Optional standby systems under Article 702, installed purely for business continuity, may use manual transfer in some cases, but once you are feeding building wiring a listed transfer device, manual or automatic, is still mandatory. In practice nearly all commercial facilities choose an Automatic Transfer Switch so that power restoration is automatic, predictable, and consistent with insurer and authority having jurisdiction expectations.

If you already have an identified tie-in point and a suitable rental generator is available, emergency temporary power can often be set up within hours to a day. A portable generator rental can typically be arranged on short notice: same day or next day for commercial units. On-site setup requires a qualified electrician to handle cabling, grounding, and connection to your distribution system or temporary panels. If a new temporary power service with a pole and utility meter is needed, the process is longer: design, permit, inspection, and utility scheduling can take weeks to months, so that path is for planned projects, not same-day emergencies. Cali Rollin Electric works with key commercial clients to pre-plan load priorities, safe connection points, and cabling routes in advance so that in an actual outage we can bring in a rental generator and restore power as fast as logistics allow.

Cali Rollin Electric pulls the electrical permit as the C-10 electrical contractor of record with whichever Santa Clara County city or the county building department has jurisdiction over the site. A temporary power service also needs a service application with the serving utility (PG&E across most of the county, Silicon Valley Power in the City of Santa Clara), because the utility sets the temporary service and installs the meter. Commercial electrical permits generally run $750 to $2,500 or more depending on jurisdiction and job valuation. The realistic schedule driver is not the permit fee, it is the sequence: permit issuance, then rough inspection of the temp pole and grounding electrode, then the utility set. Opening the utility application at the same time as the permit, rather than after the inspection passes, is usually what keeps a job site from sitting dark for two extra weeks.

Both are common in Santa Clara County and the right answer depends on runtime, siting, and permitting. Diesel units carry their own fuel, start quickly, and hold full load well, which is why they dominate life-safety applications, but a stationary diesel standby engine generally needs an air district permit from the Bay Area Air Quality Management District and fire department review for the fuel tank, plus a fuel maintenance and polishing plan. Natural gas units draw from the utility gas main, so there is no tank and no fuel storage review, but the gas service and meter have to be confirmed to carry the added demand, and a larger meter or regulator can add lead time. Runtime during a regional event also depends on the gas system staying up. Our team scopes the electrical integration either way and flags the permitting path before equipment is ordered, so the schedule reflects the real approvals rather than an optimistic one.

A generator that has never been exercised is a very expensive assumption. Which rulebook applies depends on what the generator is. NFPA 110 reaches emergency power supply systems classed Level 1 or Level 2, and it excludes optional standby systems outright (1.1.3), so a set installed under Article 702 to protect a business rather than life safety is not an NFPA 110 system. Where the system is in scope, NFPA 110 requires the emergency power supply system to be exercised under load at least once monthly for a minimum of 30 minutes (8.4.2). That is a requirement with a hard floor, not a rule of thumb. On a diesel the run has to reach at least 30 percent of the standby nameplate kW rating, or the minimum exhaust gas temperature the engine manufacturer specifies (8.4.2.1.1), and a supplemental load bank is permitted to get there (8.4.2.1.1.1). Spark-ignited units, natural gas sets included, run the available load with no percentage floor at all (8.4.2.1.2). A diesel installation that cannot reach the monthly minimum on building load owes the annual supplemental load bank test instead: 50 percent of nameplate for 30 continuous minutes, then 75 percent for one continuous hour (8.4.2.4). That annual test is conditional and diesel only, not something every generator owes. On an optional standby set, where NFPA 110 does not apply, the manufacturer service schedule governs, and our team still uses the NFPA 110 intervals as the practical benchmark because the failure modes are identical. Fire and building officials, and most commercial insurers, expect a maintenance and test record for any system serving egress lighting or a fire pump. The failure modes we see in the field are boring and preventable: a dead starting battery, stale fuel, a closed fuel valve, a block heater that quit, or an ATS that has never actually transferred under real load. We commission the system with a transfer test under load and document the result, and we can scope recurring testing alongside our commercial maintenance work.

Yes. Cali Rollin Electric is registered with the California Department of Industrial Relations (DIR registration 2000016468) for public works and holds SB and SB-PW certifications, so our team can carry the electrical scope on a prevailing-wage project and submit certified payroll through the DIR system. On public works job sites the temporary power scope usually carries extra documentation: the approved temporary service drawing, grounding electrode verification, GFCI and assured equipment grounding records for cord and plug tools, and a removal plan for the temporary wiring at close-out. We plan that paperwork into the schedule at the start rather than chasing it during punch.