Standby generator and ATS
Natural-gas or propane unit on a pad, an automatic transfer switch at the service, and a load selection so the AC, refrigeration and essentials carry through without you touching anything.
How we do it commercially →Home Standby Generator Installation in Tucson, AZ
Tucson outages are monsoon outages: a storm takes a feeder down at 5 p.m. in August and the house is 95 degrees by 7. A standby generator is what keeps the air conditioner, the refrigerator and the medical equipment running until TEP restores it. Arizona Electrical Solutions is a licensed electrical contractor (ROC CR-11) that installs and wires home generators the way we install commercial ones — sized to the load, with a proper transfer switch, permitted and inspected. Start with what you want to keep running.
What It Involves
Two kinds of home generator, one rule
There are two honest ways to back up a house. An automatic standby generator, on natural gas or propane, starts itself and switches the house over through an automatic transfer switch. A portable generator with a manual transfer switch or an interlock kit and an exterior inlet is the budget version: you roll it out, plug it in, and flip the switch yourself. Both are legitimate; they are just different amounts of money for different amounts of convenience.
The one rule that does not change is the transfer switch. A generator must never be connected to a house in a way that can back-feed the utility line — it can kill a lineworker — and the code (NEC Article 702) requires a transfer means that makes that impossible. Extension cords through a window are not a backup plan; a “suicide cord” into a dryer outlet is a felony waiting to happen. We install the switch or interlock every time.
Inlet and interlock
An exterior generator inlet, a listed interlock kit or manual transfer switch at the panel, and a labelled list of what you can run. The affordable, code-compliant way to use a portable generator.
If the panel has to change →Sized to what you keep
Whole-house or essential loads — the difference is the generator size and the price. We size it from the load you actually want to run, including the AC compressor’s starting current.
Try the load calculator →Decisions
What to decide before you buy a generator
Most of the cost is settled by four choices. Make them first and the quote is simple.
Whole house or essentials
Running the whole house through an outage in August means a big unit. Backing up the AC, the refrigerator, the well pump and a few circuits is usually a smaller generator and a smaller bill.
Gas or propane
Southwest Gas service makes natural gas the easy choice where it exists; propane needs a tank and a supplier. The gas connection is done by a licensed gas contractor we coordinate with.
Where it sits
Clearance from windows, doors and property lines, a level pad, and a place where the exhaust and noise are acceptable. Manufacturer and code clearances decide more of the placement than preference does.
The panel it lands in
A transfer switch needs room at the service. An old or full panel, or a Federal Pacific, is usually replaced at the same time; it is cheaper together than as two visits.
Commercial Standard
Wired the way we wire a building’s standby power
We install generators and transfer switches on commercial buildings, where the standby system is life-safety equipment and the inspection is unforgiving. A home generator gets the same conductor sizing, the same transfer-switch wiring and the same labelling. The difference is scale, not care.
That includes the boring parts that get skipped on a cheap install: the generator disconnect, the signage at the service that tells a lineworker there is an on-site source, and a load list on the transfer switch so the next person knows what it carries.
- ROC CR-11 electrical licence; generator and transfer switch wired per NEC 702
- Load selection sized from what you want to run, including motor starting current
- Automatic or manual transfer — never a back-feed
- Signage and labelling at the service, as the code requires
- Start-up and a documented test under load before we leave
Permits & Utility
Permitted, inspected, and known to the utility
A generator installation is permitted electrical work in every Tucson-area jurisdiction, and the transfer switch is what the inspector looks at hardest. A gas-fired unit also involves a mechanical or plumbing permit for the fuel line, pulled by the gas contractor. We coordinate the sequence so it is inspected once.
TEP and Trico both want to know a home has an on-site source; the placard at the service is how that happens. We take care of it.
- Electrical permit with the City of Tucson, Pima County, Marana, Oro Valley or Sahuarita
- Gas connection by a licensed gas contractor, coordinated with our schedule
- Inspection scheduled and met
- See your address’s permit history with the free property lookup
FAQ
Tucson home generator questions, answered
What size generator do I need for my Tucson home?
It depends on what you want to keep running. The air conditioner is the big one: its compressor’s starting current, not its running current, sets the minimum. A whole-house backup for a typical Tucson home is a large unit; backing up the AC, the refrigerator and a few circuits is often half the size. We size it from your actual equipment, and our load calculator gives you a first look.
Can I just plug a portable generator into my house?
Not without a transfer switch or interlock. Back-feeding a house through an outlet can energise the utility line and kill a lineworker, and it is illegal. A portable generator inlet with a listed interlock kit at the panel is the affordable, code-compliant way to do it, and it is a small job for us.
Do I need a permit for a home generator?
Yes. The electrical work — the transfer switch, the inlet, the generator circuit — is permitted and inspected in every Tucson-area jurisdiction. A gas-fired generator also needs the fuel line permitted, which the gas contractor handles.
Natural gas or propane?
If Southwest Gas serves your street, natural gas is simpler: no tank, no deliveries. Propane is the answer where there is no gas service. Either way the fuel connection is made by a licensed gas contractor we coordinate with; we do the electrical.
Will my panel need to be replaced?
Often not, but a transfer switch needs room at the service and an old, full or Federal Pacific panel is usually replaced at the same time. It is cheaper to do together. See our residential panel upgrade page.
Do you service generators after installation?
We do the start-up and a load test at installation and we can return for scheduled maintenance. We are not a 24-hour emergency service; if the generator fails to start during a storm at night we will get to you the next working day.
Related Services
Work that usually comes with this one
One licensed contractor for the whole job. See everything we do for Tucson homes.
Residential Panel & Service Upgrades
Home panel and service upgrades — 100A to 200A, FPE and Zinsco replacement, permits and utility coordination.
Home AC & Heat Pump Replacement
AC and heat-pump replacement with the circuit and disconnect — CR-39 and CR-11 under one roof.
Residential Load Calculator
Whole-house load and service size by the NEC 220.82 method — free.
Residential Electrician
Everything we do for Tucson homes — panels, EV charging, AC, casitas, rewiring and generators.
Decide what stays on, then call
Tell us what you want to keep running in an outage and send a photo of your panel and meter. We will size the unit and the transfer switch, and quote the electrical side in one number.
Request a Quote Call (520) 308-6235