by Ali Kriscenski


The benefits of properly sized wire ampacity and electrical systems include safety, fire prevention and sufficient system capacity. Another benefit can be increased energy efficiency and associated cost savings. With some forward planning, upsizing wiring can increase safety, create opportunities for expansion and increase energy efficiency.


Why Wire Size Matters

Electricity can be slowed down by wire size, and it can move slower through smaller wires. For this reason, larger amp systems are coupled with larger wires. This can be seen in the electrical service entrance cables, where their amperage is a function of their material composition and diameter. The same is true of a building’s electrical system. The wire materials and sizes determine the maximum load capacities.


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A wire’s rating is based on the American Wire Gauge (AWG) system where the rating indicates the current-carrying capacity and the safe amperage (rate of electron flow) limit. If electrical wires are too small for the current or amperage, the load can create a short circuit of electrical devices or even cause a fire hazard.  


When to Check Wire Ampacity

The electrical demand on your system will be delivered by its wires, so they need to be sufficient for the load requirements. Any major upgrades, improvements, or renovations to a facility or building can create more demand on the wires. These can include equipment or appliance upgrades, an addition that adds outlets and lighting, or a compliance-required improvement. All of these instances are when wire ampacity should be verified and, if needed, updated or replaced.


How Increased Wire Ampacity Creates Savings

It’s common knowledge that buildings consume a lot of energy, some 40% of all US energy consumption. Evolving regulations around climate change and carbon emissions have fueled changes in the construction industry towards increasing energy efficiency. The gaps between building codes, which are typically geared towards safety, and voluntary building standards aimed at carbon and energy use reduction are apparent in the increased wire ampacity opportunity.

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The National Electrical Code (NEC), approved by the American National Standards Institute (ANSI),  is the most widely adopted standard for electrical installations. The standard sets the minimum requirement for wire size to prevent safety and fire hazards. When applicable, wire size can be increased above the NEC to improve energy efficiency and accommodate future system upgrades.


Facilities that can utilize economies of scale to capture the energy savings can see quick returns on the wire-size upgrade. The increased capacity to handle future load changes can also provide the opportunity to increase energy efficiency through equipment upgrades or system improvements. For example, adding a cogeneration component to a facility’s energy system. The increased wire size may also lower the heat produced by manufacturing or other activities and yield energy savings in cooling.


Energy Efficiency Incentives

Increasing electrical system capacity to accommodate future changes or opportunities can prove to be a cost-effective strategy. Federal and state programs are increasingly leaning towards rebates and other incentives for commercial and residential renewable energy. The Database of State Incentives for Renewables and Efficiency (DSIRE) is run by the N.C. Clean Energy Technology Center at N.C. State University. It is one of the most comprehensive and current sources of energy efficiency and renewable energy incentives. 


The incentives database can help identify ways to offset qualified capital investments. Even if those upgrades are further down the road, they can be planned for when making improvements to electrical service and wiring. You can enlist the expertise of your service technician to discuss any future load requirements in the pursuit of energy-efficient and renewable upgrades.


Finding the Right Electrical Know-How

The expertise needed to navigate standard codes, identify cost-effective upgrades and create systems to accommodate future improvements requires a skilled professional. The investment in working with a highly trained electrician familiar with heavy mechanical system upgrades can create long-term savings and operational efficiency. Contact Therma today to learn more about how our engineers and technicians can deliver on your energy goals.


Ali Kriscenski was trained in high-performance building design at Boston Architectural College. She has worked with leading architecture and construction firms in NYC and New England and served on the executive team at the Forest Stewardship Council International. She was the managing editor at Inhabitat and has worked pro bono for the Green Building Institute, ISEAL Alliance and Habitat for Humanity.



US Energy Information Administration — How Much Energy is Consumed in US Buildings

Copper Development Association — One Wire Size Up Means Big Savings