Generators and Standby Power
Keeping the loads that cannot stop running when the utility goes out.
ThreeCo installs generators and the electrical work that connects them to a building. A standby generator is only as useful as its connection: the transfer switch that moves the building over when the utility fails, the circuits it is allowed to carry, and the wiring between the two. Get those wrong and a generator either cannot start the loads it was bought for or sits idle while the building goes dark.
Most of the decisions are made before anything is ordered — which loads matter, how quickly they need power back, and how much generator that adds up to.
Signs a building needs standby power
- An outage costs real money: refrigeration full of stock, a server room, production that stops, a business that has to close its doors.
- Something in the building cannot be allowed to stop — a sump or lift station pump, medical or lab equipment, a freezer.
- Outages have been frequent or long enough that the question keeps coming up after every storm.
- An insurer, a landlord or a customer contract asks for backup power.
- A rented portable generator and extension cords have become the plan, and nobody likes the plan.
Whole building, or the loads that matter
The first decision is what the generator has to carry. Backing up the whole building is simplest to wire and the most expensive to buy and fuel. Backing up chosen loads — the refrigeration, the server room, the pumps, some lighting and receptacles — means moving those circuits onto a separate panel that the generator feeds, and it lets a smaller generator do the job.
Some buildings are required by code to have emergency power for life safety, such as exit lighting, and that is a system designed into the building's plans. Most standby generators are the owner's choice, to keep the business running; which kind a building has changes what the installation must meet, so it is settled first.
What an electrician checks first
- 1
The loads
We list what has to keep running, and look at the motors in it — a compressor or a pump draws several times its running power for a moment as it starts, and the generator has to ride through that.
- 2
Load calculation
From that list comes the size of generator the building actually needs, rather than a guess with a margin on top.
- 3
The transfer switch
An automatic transfer switch starts the generator and moves the load over on its own when the utility fails, and moves it back when power returns. A manual switch needs someone on site to do it. Either one keeps the generator from feeding power back onto the utility’s lines, which is a danger to line crews.
- 4
Panel and service
We look at where the transfer switch fits between the service and the panels, and whether the panel being backed up has to be split so only the chosen circuits move over.
- 5
Placement and the run
The generator sits outside, on a pad, at the distances from doors, windows and air intakes the code and the manufacturer require. Its distance from the transfer switch sets the size of the wire between them.
- 6
Permit and inspection
A generator installation is permitted and inspected, and the transfer switch is tested before the job is closed out.
The fuel supply
A standby generator runs on natural gas, propane or diesel. This page is about the electrical side — the generator's connection, the transfer switch and the circuits. Running a gas line to the generator is a separate trade from electrical work, and it is planned alongside it so the pad, the fuel and the wiring arrive in the right order.
What affects the cost
We do not publish prices. What moves the number: the size of generator the load calculation calls for; whole-building or chosen loads, and how many circuits move to a separate panel; automatic or manual transfer; the distance from the generator's pad to the transfer switch; whether the existing service and panels need work to fit the switch in; and what the city requires. You get a written quote after the walk-through.
FAQ
Questions about generators and standby power
What size generator do we need?
That comes from a load calculation over the loads you want backed up, including the extra power motors draw as they start. We do it before quoting, so the generator is neither too small to start the equipment nor bigger than you need.
What is a transfer switch, and do we need one?
It is the switch that moves the building, or chosen circuits, from the utility to the generator and back. A permanently connected generator needs one: it is also what stops the generator feeding power back onto the utility’s lines.
Automatic or manual transfer?
An automatic switch starts the generator and moves the load over by itself within moments of an outage; a manual one needs someone on site. If nobody is there at night or on weekends, or the loads cannot wait, automatic is the answer.
Can a generator back up only part of the building?
Yes. The circuits that must keep running are moved onto a separate panel that the transfer switch feeds, and only that panel goes over to the generator. It usually means a smaller generator than backing up everything.
How do I get a quote?
Start with Watt, the chat button on this page. Tell it the address and what has to keep running in an outage. You can also call (816) 730-9100. Estimates are free unless a site visit is needed to scope the job; where one is, there is a trip charge, waived if you move forward with the work.
Tired of losing a day to every outage?
Tell Watt the address and what has to keep running. We will start from the loads, not from a generator size.
New customers: start with Watt and get 10% off your first job.