Is Your Business’s Backup Power Ready for the Next Storm? A Readiness Check
Backup power is ready only if it has recently carried the building’s real load, started on its own, and transferred cleanly. A generator that runs fine when idle can still fail under load. A transfer switch that has never been exercised can stick, and a starting battery can look healthy and still fail to crank on a cold morning. The most reliable way to find these problems is a readiness check before the storm, not a scramble during the outage. Emergency generators are commonly exercised at least monthly for 30 minutes at not less than 30 percent of nameplate under NFPA 110, with an annual load bank test for diesel units that cannot reach that load. This guide gives facility managers and building owners in Indianapolis and central Indiana a practical readiness checklist, explains why backup systems fail when they are needed, and shows who should handle each task.
What “Ready” Means for Commercial Backup Power
A backup power system is a chain, and the chain is only as strong as its weakest link. The main parts are the generator itself, the fuel supply, the starting batteries and charger, the controls, the automatic transfer switch, the distribution panels that feed backed-up circuits, and the cooling, exhaust, and enclosure. Many businesses add a UPS to carry sensitive equipment through the seconds before a generator is online. Readiness means every link has been checked and the system as a whole has been proven under load.
NFPA 110 is the standard for emergency and standby power systems. It applies to emergency and legally required standby systems, and many owners use it as the maintenance benchmark for optional standby units as well. You can read more about it at NFPA 110, and a state fire marshal’s generator testing fact sheet summarizes the monthly exercise, load bank, and recordkeeping practices in plain language. Our backup power solutions and generator installation and transfer switch describe the equipment side.
Why Backup Power Fails When It Is Needed
- Weak starting batteries or a failed charger. Batteries age, and a charger fault can leave a battery undercharged for weeks without anyone noticing.
- Stale or contaminated fuel, or too little of it. Stored fuel can degrade and collect water, and tank levels often drift down.
- Light-load running. Diesel engines that run for years with little load can build up carbon, which a load bank test helps clear.
- Open or tripped breakers. A breaker left off after maintenance or a prior event can keep power from reaching the transfer switch or the backed-up circuits.
- An unexercised transfer switch. Contacts and controls that never operate can stick or fail to sense an outage.
- Cold-weather problems. Cold lowers battery capacity, and ice or snow can block louvers or access.
- Load growth. Equipment added since the generator was sized can push the total load beyond capacity. Our article on how load growth creates electrical instability explains how this accumulates.
- Floodwater. Equipment at or below grade can be damaged before the outage even begins.
- Unclear procedures. Staff who do not know how to respond to an alarm or a failed transfer lose time.
Warning Signs Your Backup Power May Not Be Ready
- No exercise or test has been logged in the past month
- The generator only ever runs with no load, or no one knows what load it carried
- The transfer switch has never been exercised under load
- The starting batteries have no recorded age or test date
- Fuel levels or fuel quality are not checked on a schedule
- Equipment has been added since the system was last sized
- Alarms or fault indicators have been left unresolved
- No one on staff has a written procedure for an outage
If several of these apply, schedule a review before the next storm. Our guides to automatic transfer switches in commercial buildings and standby generators for Indianapolis businesses explain the components in more depth.
The Backup Power Readiness Checklist
Use this checklist as a starting point and adjust it to the equipment installed in your building. Items marked for a contractor involve energized equipment, specialized test equipment, or code-governed work.
| Item | What to check | Who and how often |
|---|---|---|
| Exercise run | Runs and carries load for at least 30 minutes, with the load documented | Facility staff, monthly |
| Transfer test | The transfer switch moves essential loads to the generator and back | Facility staff with an electrician, on a regular schedule |
| Starting batteries and charger | Age, voltage, connections, and charger output | Staff for visual checks, contractor for testing |
| Fuel | Level, quality, water, and a plan for resupply | Staff for level, fuel service provider for quality |
| Fluids and belts | Oil, coolant, belts, hoses, and leaks | Staff for visual checks, contractor for service |
| Cold-weather readiness | Block heater, battery condition, and clear louvers and access | Staff and contractor, before winter |
| Load bank test | Capacity and combustion health under loading | Generator contractor, annually where required for the unit |
| Transfer switch inspection | Contacts, controls, and settings | Contractor, annually |
| Breakers and panels | Breaker positions, labels, and load priority list | Licensed electrician |
| Exhaust and enclosure | Clear exhaust path, louvers, and enclosure condition | Staff, with contractor review |
| Alarms and monitoring | Alarm function and notification path | Staff and contractor |
| Records | Log of every run, test, fault, and service | Facility staff |
Facility Staff vs. Licensed Contractor: Who Does What
Staff can handle a lot of day-to-day readiness. Load testing, transfer switch inspection, and anything that involves opening energized equipment belong to licensed professionals. The state fire marshal summary describes the annual load bank test as work performed by a generator contractor, and electrical work should follow the safe practices described by OSHA.
| Task | Facility staff | Licensed professional |
|---|---|---|
| Run and log the monthly exercise | Yes | Reviews logs |
| Check fuel level, fluids, and visible leaks | Yes | Services the unit |
| Keep the enclosure and louvers clear of snow and debris | Yes | Not applicable |
| Maintain a written outage procedure and contact list | Yes | Advises |
| Test and inspect the transfer switch contacts and controls | No | Required |
| Load bank test | No | Generator contractor |
| Breaker, panel, and load priority review | No | Licensed electrician |
| Replace batteries, repair controls, or service the engine | No | Required |
Solutions: Closing the Gaps a Readiness Check Finds
| Gap found | Typical response | Notes |
|---|---|---|
| Generator never carried load | Schedule a load test and exercise under real or simulated load | Establishes a baseline and clears light-load buildup |
| Weak batteries or charger | Replace batteries and verify charger output | Add dates to the maintenance log |
| Fuel quality or quantity unknown | Test, condition, and plan resupply | Set a recurring check |
| Transfer switch unexercised | Test under load and inspect contacts | Document results |
| Load has grown | Recalculate load and stage or add capacity | Update the priority list |
| No ride-through for sensitive equipment | Add or service UPS systems | See our UPS maintenance service |
| Equipment at flood risk | Relocate or elevate critical equipment | See our flood guidance below |
| No outage procedure | Write a one-page procedure and train staff | Review annually |
Backup Power Approaches: Strengths and Limits
| Approach | Strengths | Limits |
|---|---|---|
| Generator with automatic transfer switch | Carries the building for hours or days and can serve large loads | Takes seconds to start and transfer, and depends on fuel, batteries, and regular testing |
| UPS only | Switches over instantly and protects servers, registers, and controls | Limited runtime, and not designed to carry HVAC or other large motor loads |
| Generator plus UPS | The UPS bridges the start-up gap while the generator carries the longer outage | More equipment to maintain and test, and the load plan must be coordinated |
Backup power is one part of the building’s electrical system. Our power distribution upgrades and circuit breaker panels and sub-panels services keep the equipment between the utility and your loads in order, and surge protection helps protect electronics through the restoration of power, as explained in our guide to whole-building surge protection vs. power strips.
Local Context: Storms, Floods, and Outages in Central Indiana
Central Indiana faces a mix of summer thunderstorms, winter ice and wind, and flooding. The region experienced record river flooding in August 2026, including a record crest on the White River at Noblesville, according to the National Weather Service in Indianapolis. Flooding matters for backup power because generators, transfer switches, and panels at or below grade can be damaged before an outage ever begins. FEMA’s floodproofing guidance for commercial buildings notes that electrical utilities below the flood protection level need to be protected and that sump pumps may need alternate power.
If your equipment was exposed to floodwater, see our flood damage response service and our guides on flooded HVAC electrical components and flood-proofing a commercial mechanical room. For storm recovery, use our storm damage checklist for facility managers.
Your outage response also depends on your electric utility, which varies by address. Central Indiana properties may be served by Duke Energy, AES Indiana, or a local electric cooperative, so confirm your provider’s outage reporting process and add it to your written outage procedure. Our Fishers generator and transfer switch covers service in Fishers, and our emergency electrical repairs team responds when a storm disrupts operations.
Why Choose Mission Mechanical for Commercial Backup Power
| What We Offer | What It Means for You |
|---|---|
| Indiana Licensed Commercial Electricians | State-verified expertise and fully code-compliant work on every commercial electrical project |
| Fully Insured (GL + Workers Comp) | Zero liability exposure for your business at every stage of the project |
| BBB Accredited, A+ Rating | Third-party verified trust record backed by a nationally recognized consumer organization |
| Highly Rated on Google and Yelp | Consistently recognized by commercial clients for service quality and technical accuracy |
| 23 Years Serving the Indianapolis Area | Deep local knowledge, established commercial relationships, and a proven track record since 2002 |
| Indianapolis Colts Small Business Partner 2026 | An active and recognized participant in the greater Indianapolis commercial business community |
| MICCS Safety Member | Verified commitment to jobsite safety standards on every commercial electrical project |
| Schedule Service Online | Request commercial electrical service at any time through our online scheduling system |
Frequently Asked Questions: Commercial Backup Power Readiness
How do I know if my business’s backup generator is ready for a storm?
Backup power is ready when it has recently run under real building load, started on its own, and transferred cleanly through the transfer switch. A generator that runs when idle can still fail under load, so check the test log, the starting batteries, the fuel supply and condition, the transfer switch operation, and whether anything has been added to the building since the system was sized.
How often should a commercial generator be tested?
NFPA 110, as summarized by a state fire marshal’s office, calls for exercising emergency generators at least monthly for 30 minutes at not less than 30 percent of the nameplate rating. That standard applies to emergency and legally required standby systems, and many owners use it as the benchmark for optional standby units too. Confirm the requirements that apply with your local authority and insurer.
What is a load bank test and why is it needed?
A load bank test runs the generator against an artificial load so it works as hard as it would in a real outage. The state fire marshal summary describes an annual two-hour test for diesel units that cannot reach 30 percent load during monthly runs, stepping through 25 percent for 30 minutes, 50 percent for 30 minutes, and 75 percent for 60 minutes, performed by a generator contractor. It helps clear carbon buildup from light-load operation and proves capacity.
Why do standby generators fail to start during an outage?
The most common causes are weak or dead starting batteries and failed chargers, stale or contaminated fuel, low fuel levels, open or tripped breakers, control faults that were never cleared, and cold-weather starting problems. Most of these can be found with regular testing, which is why a generator that is never exercised carries the most risk.
What is wet stacking in a diesel generator?
Wet stacking is the buildup of unburned fuel and carbon in the exhaust system of a diesel engine that runs lightly loaded for long periods. It reduces performance over time. Sufficient load, including load bank testing, helps clear it.
What does an automatic transfer switch do, and should it be tested?
An automatic transfer switch detects a loss of utility power, signals the generator to start, and moves the building’s essential loads to generator power, then returns them when utility power is stable. It should be exercised under load and have its contacts and controls inspected on a regular schedule, since a switch that has never transferred can fail when it is needed.
How long will my generator run on its fuel supply?
Runtime depends on the tank size, the fuel type, and the load the generator is carrying. A runtime calculation based on your actual load is more reliable than a rule of thumb. Also plan how fuel will be replenished during a long outage, since road conditions and supplier availability can change during a storm.
How do I keep generator fuel from going bad?
Stored fuel can degrade over time and can collect water. Regular fuel quality checks, conditioning or filtering when needed, keeping tanks properly maintained, and rotating stored fuel help keep the supply usable. A generator service provider can test fuel and recommend an interval for your equipment.
Does cold weather affect generator starting?
Yes. Cold reduces battery capacity and thickens oil, and block heaters and battery maintenance matter more in winter. Snow and ice can also block intake and exhaust louvers or restrict access to the unit. A pre-winter check should include the heaters, batteries, and the area around the enclosure.
Which circuits should be on backup power?
Build a priority list that starts with life safety loads such as egress lighting and fire alarm systems, then adds critical operations such as IT and communications, refrigeration, essential HVAC, security, and point-of-sale. Not every circuit needs backup, and a clear priority list helps size the generator correctly and keeps the transfer switch and panels organized.
Can a standby generator power commercial HVAC equipment?
Often, but inrush current matters. Compressors and large motors draw much more when they start than when they run, so the generator, the transfer switch, and the staging of loads need to be sized with that in mind. A load calculation shows what the generator can carry and what should be staged or left off backup.
What is the difference between a UPS and a generator?
A UPS uses batteries to carry equipment instantly during a short outage or while a generator starts, protecting servers, registers, and controls from dropping out. A generator provides power for hours or days but takes seconds to start. Many businesses use both, with the UPS bridging the gap.
Can flooding damage backup power equipment?
Yes. Generators, transfer switches, and distribution panels installed at ground level or below grade can be damaged by floodwater. Equipment that was submerged should not be restarted until a qualified evaluation is complete, and elevating critical equipment reduces the risk for future events. Our flood response team can help assess affected electrical equipment.
What records should a business keep for its backup power system?
Keep a log of every exercise and test with the date, run time, load, and any alarms or faults, along with fuel and battery service records and maintenance reports. These records show inspectors and insurers that the system is maintained and help technicians diagnose problems faster.
How can a business schedule a backup power readiness review?
Call Mission Mechanical at 317-733-8686 or request service online. A licensed electrician will review the transfer switch, distribution, load priorities, and related electrical equipment for properties in Indianapolis, Lawrence, and surrounding central Indiana communities. Engine-side service and load bank testing are typically handled by a generator service contractor.
When to Call Mission Mechanical
Mission Mechanical has provided licensed commercial electrical service throughout Indianapolis, Lawrence, and central Indiana since 2002. Our Indiana Licensed Commercial Electricians handle the electrical side of backup power, including transfer switches, distribution, load priorities, and UPS systems. Engine-side service and load bank testing are typically handled by a generator service contractor, and we can help you sort out which tasks belong where. We carry full general liability and workers compensation insurance, and Mission Mechanical is BBB A+ accredited. Our commercial clients consistently recognize our work on Google and Yelp. Mission Mechanical is a MICCS safety member and an Indianapolis Colts Small Business Partner 2026. Contact us at 317-733-8686 or contact our team online to schedule a readiness review, and explore our full commercial electrical services for Indianapolis and central Indiana.
Not sure your backup power would carry the building? Call Mission Mechanical at 317-733-8686 or request a backup power readiness review online before the next storm. Indiana Licensed Commercial Electricians. Fully insured. BBB A+.
