Article Date – June / July 2025
Restaurant Facility Management Association – Facilitator Magazine
A quick guide to understanding your electrical systems in your commercial kitchen
As restaurants grow, update menus, or attempt to embrace energy-efficient technologies, upgrading the electrical system often becomes essential. Commercial kitchens have quite a bit of electrical demand, and outdated or undersized systems can lead to equipment failure or safety hazards. This guide should provide a better understanding about what contractors may be looking at and what questions may be asked, but it is for reference only. Upgrades should be assessed by an experienced contractor or engineer.
Why and When to Upgrade Your Electrical System
An upgrade is generally considered in two cases: (1) when either the entire system or a portion of it is undersized (i.e., not enough amperage capacity) for your current or future needs or (2) there are hazards or frequent failures. Both scenarios may arise during the pre-construction phase of a renovation or improvement, which would typically involve the construction or development team. However, the frontline information will likely be coming from site personnel or your vendor partners. Regardless, be aware of:
Frequently tripped breakers or outages
Overheated panels or wiring
Strained equipment startups or shutdowns (voltage drops)
Antiquated equipment (e.g., stab-on breakers, old Zinsco/Federal Pacific equipment)
Should these issues arise, it’s time to act. Modern computerized maintenance management systems (CMMS) are a good place to begin compiling your service history notes and photo data for the site before consulting with an electrical contractor or engineer for recommendations.
Understanding Electricity: Volts, Amps and Watts
Here are some basic definitions and calculations you should know:
Voltage (V): The “pressure” that pushes electricity through the wires
Amperage (A): The volume or “flow” of electricity through the wires
Wattage (W): The power being used by equipment
To better understand your equipment and/or site needs, use these basic formulas to ensure your system can handle the load(s):
Watts = Volts × Amps
Amps = Watts / Volts
Volts = Watts / Amps
Kilovolt Amps (kVA) = total wattage / 1000 (using load class below to size transformer)
Example: If you install a 6,500-watt oven on a dedicated 208V circuit, the equipment demand is 31.25A (A=W/V). The breaker should be 125% larger than the load, allowing the load demand to remain within 80% of the breaker rating, meaning the oven should be on a 40A breaker (wires to match breaker size — undersized wire is a fire hazard).
Equipment Load Classifications
Constant loads — Calculated at 100% of their value: refrigerators, HVAC, motor loads
Intermittent loads — Calculated at 50% of their value: mixers, slicers
Standby loads — Calculated at 10% of their value: rarely used items
Common Voltage Configurations
Your contractor or engineer will want to know the type and size of service for the location if inquiring about upgrading. If plans are available, identifying the service voltage and main amperage rating is straightforward. These details can be found in your E-sheets with the one-line diagram and panel schedules. Otherwise, a site visit will need to be completed. As an FM, you may be able to obtain the necessary information if the equipment nameplates are still legible. Plans may also be hidden in or around electrical rooms or the manager’s office.
Below are a few common voltage configurations you should know:
Single-phase 120/240V — (Black/Red/White) Typical in smaller restaurants or older buildings. Despite the term “single-phase,” this voltage is two hot legs which have been split from a single phase at the utility transformer.
Three-phase 120/208V wye — (Black/Red/Blue/White) Common in commercial kitchens, suitable for high-demand equipment, and more efficient than single-phase systems.
Three-phase 277/480V wye — (Brown/Orange/Yellow/Gray) Higher voltage for large-scale operations or buildings with significant HVAC, refrigeration needs, or larger parking lot lighting demands where distance is a factor.
When to Upgrade or Change Your Utility Service Voltage
A common scenario: your site is running on a single-phase 120/240V service. Since this voltage is generally less efficient for HVAC, refrigeration, or motor loads, this would be a good candidate for upgrade to three-phase 120/208V wye if available from the utility. It is worth noting that all 240V equipment would need to be evaluated for voltage tolerance and may require full swap or buck/boost transformer to change dedicated equipment voltage.
Transformers (XFMR): Functions and Reasons for Upgrading
Transformers adjust the voltage either up or down. Large step-up transformers are less common in the restaurant industry. You may see a piece of equipment with the previously mentioned 208V primary/240V secondary buck/boost transformer.
XFMR Example: A building with 277/480V service may use a 277/480V load center for parking lot lighting and HVAC/motor loads. A breaker on the 480V load center (or out of the main distribution panel) then feeds a transformer, stepping the voltage down to a more standard 120/208V.
Overloading primary side main means XFMR kVA is undersized
May be required if upgrading utility service
Panels and Load Centers
Main distribution panel (MDP): The central hub for facility-wide power
Load center: A main panel that distributes power to specific areas, often used interchangeably with “subpanel” in smaller facilities, but technically different
Subpanel: A secondary panel fed from the load center, situated near high-demand areas
Smart panels: Newer in light commercial applications, offering real-time load tracking, alerts, and remote diagnostics
Keys for Assessment and Planning
Review as-built plans — the best starting point as they provide the most detailed information.
Compile data — use your CMMS to gather all service history notes and photos; visit site if necessary.
Vendor consultation — use your partners. Pass along all information and build strategy.
Load analysis — understand total demand, both existing and planned. Calculate peak and simultaneous loads using a phase analyzer to monitor load data over 30 days, with higher readings expected during summer months.
Accurate load schedule — a chart showing circuit identification and load summary (existing and proposed).
Load balancing — critical in three-phase systems. Unbalanced panels can cause inefficiencies, overheating, or equipment damage. Balancing ensures each phase handles an equal portion of the load.
Single-line/one-line diagram — a simplified diagram showing your entire electrical distribution, from the main panel to subpanels and equipment.
Feeder verification — check if the existing feeder (the main wire from the utility) is adequate. May not require utility upgrades if within amperage tolerance.
Involving the Right Experts
A licensed commercial electrician to evaluate, design, obtain permits, and install your upgrades
An electrical engineer for infrastructure modifications, transformer additions, or voltage changes
Your local utility company to confirm power availability and any required infrastructure upgrades
Lead times can vary, so begin coordination early.
Conclusion: Planning for a Safe, Efficient Future
An electrical upgrade is an essential investment in safety, performance, and growth. Whether you’re remodeling, adding new kitchen equipment, or preventing power issues, a methodical approach is key to success.
Key Takeaways:
Understand how voltage, amperage, and wattage interact to drive your equipment.
Conduct a thorough load analysis and ensure proper system balancing.
Size transformers and panels for current needs and future flexibility.
Work with qualified professionals and coordinate early with your local utility company.
By planning upgrades with foresight and expert input, your site will be ready to operate safely, efficiently, and without limits for years to come.
