A commercial power outage isn't simply inconvenient.
It can stop production, shut down HVAC systems, compromise refrigeration, interrupt communications and IT equipment, disable pumps and leave employees or customers without critical building systems.
For many businesses, the bigger question isn't whether backup power is valuable.
It's:
What size commercial generator do I actually need?
Commercial standby generators can range from relatively modest systems to hundreds of kilowatts. Choosing correctly requires understanding the facility's electrical loads rather than simply selecting a generator based on building square footage.
Start With the Loads That Must Remain Operational
The first step is determining what needs backup power.
Typical commercial loads include:
- HVAC equipment
- Refrigeration
- Lighting
- Computers and servers
- Security systems
- Pumps
- Motors
- Commercial kitchen equipment
- Manufacturing equipment
- Office equipment
- Communications systems
- Building controls
Separate loads into:
Critical loads
and
Non-critical loads.
A warehouse that only needs emergency lighting, security and selected HVAC equipment may require substantially less generator capacity than the same warehouse attempting to maintain full operation.
kW vs kVA
Commercial generator specifications frequently use both kilowatts and kilovolt-amperes.
kW represents real power.
kVA represents apparent power.
The relationship depends on power factor.
This distinction becomes important when sizing generators for commercial facilities containing motors, compressors and other inductive loads.
Motor Starting Changes Everything
Suppose a facility's equipment consumes 70kW once everything is operating.
That doesn't automatically mean an 80kW generator is appropriate.
A large compressor or motor can require significant additional capacity during startup.
Commercial HVAC equipment, refrigeration compressors, pumps and industrial motors are particularly important examples.
The generator needs to maintain acceptable voltage and frequency while these loads start.
Commercial HVAC Loads
HVAC is often one of the largest electrical loads in a commercial building.
Equipment can include:
- Packaged rooftop units
- Split systems
- Heat pumps
- Chillers
- Pumps
- Exhaust fans
- Make-up air systems
- Air handlers
If several compressors can start simultaneously, generator sizing can become substantially more complicated.
Sequencing or load management may be appropriate in some applications.
Single Phase vs. Three Phase
Commercial facilities may use single-phase or three-phase electrical service.
Three-phase service is common in larger commercial and industrial properties because it efficiently supports larger motors and equipment.
Generator voltage and phase need to match the facility and the intended backup loads.
Common configurations can include 120/240V single phase and commercial three-phase configurations such as 120/208V or 277/480V.
Don't select a generator based only on kW capacity.
Voltage and phase are equally important.
80kW Commercial Generators
An 80kW standby generator can be appropriate for certain smaller commercial applications or facilities where only selected loads require backup.
Applications might include offices, retail operations, smaller facilities and selected HVAC/refrigeration loads.
Actual suitability depends on the load calculation.
100kW Commercial Generators
Moving to 100kW provides additional capacity for larger commercial electrical loads.
This range may be worth evaluating for warehouses, commercial buildings and operations containing multiple motors or HVAC systems.
150kW Commercial Generators
A 150kW generator moves into significantly larger commercial applications.
At this level, facilities may be supporting substantial HVAC, refrigeration, process equipment, pumps and other loads.
Proper engineering becomes increasingly important as generator capacity and electrical-system complexity increase.
200kW Commercial Generators
A 200kW generator can support substantial commercial and industrial applications.
However, the same principle still applies:
Don't choose 200kW simply because the building is large.
Determine the loads, motor-starting requirements, voltage, phase and desired operating strategy.
Natural Gas or Propane?
Fuel availability is an important part of commercial generator selection.
Natural gas can provide a convenient continuous fuel source where adequate utility service is available.
Propane provides an alternative where natural gas isn't available or where stored fuel is preferred.
Fuel-system capacity must be capable of supporting the generator at the required load.
Don't Forget Future Expansion
Commercial systems should also consider future loads.
Will the facility add:
- More HVAC equipment?
- Additional refrigeration?
- Manufacturing machinery?
- Pumps?
- Expanded office space?
- Additional building systems?
Planning for reasonable future expansion can prevent the backup-power system from becoming undersized prematurely.
Start With a Professional Load Analysis
Commercial generator sizing should be based on actual electrical data.
Gather:
- Utility/service information
- Voltage
- Phase
- Major equipment specifications
- Motor/compressor starting information
- Critical loads
- Desired operating loads
- Future expansion requirements
From there, an appropriate generator can be selected.
Commercial Briggs & Stratton Generators at ACUnitsForLess
ACUnitsForLess offers Briggs & Stratton commercial standby-generator solutions across multiple capacities and electrical configurations.
Whether you're evaluating backup power for a warehouse, office, retail operation or another commercial property, start with the building's actual electrical requirements.
A commercial generator isn't simply another piece of equipment.
It's part of your facility's continuity plan.
Shop Briggs & Stratton Commercial Standby Generators at ACUnitsForLess.
Commercial generator sizing and installation should be designed and verified by appropriately qualified professionals in accordance with manufacturer requirements and applicable electrical, fuel, fire and building codes.
