Spring Surge: Preparing Commercial Buildings for Summer Cooling Loads

Ask NETA (not Ask META) is Ask NETA - National Electrical Technical Assistant, built for electricians who need fast, practical code guidance in the field.

As winter loosens its grip and the days lengthen, it's time for commercial electricians to shift focus from heating to cooling. Summer heat places a significant strain on commercial electrical systems, and proactive maintenance and preparation are crucial for preventing outages, ensuring occupant comfort, and maintaining efficient operations. This March, let's discuss key strategies for tackling increased cooling loads in commercial buildings.

Understanding the Summer Load Surge

Commercial buildings often experience a dramatic increase in electrical demand during the summer months, primarily due to air conditioning systems. This surge can overload circuits, stress transformers, and even lead to power failures if not properly managed. Beyond AC, other contributing factors include increased use of lighting (longer days), refrigeration equipment working harder, and higher occupancy rates in certain sectors.

Essential Spring Electrical Checks

A comprehensive electrical inspection is the cornerstone of summer readiness. Here are some key areas to focus on:

• Panelboards and Distribution Equipment: Inspect panelboards (NEC 408) for loose connections, signs of overheating (discoloration, burning smells), and corrosion. Torque connections to the manufacturer's specifications. Verify proper operation of circuit breakers and replace any that appear faulty. Check the overall cleanliness of panel interiors and remove dust/debris that can contribute to overheating.
• Air Conditioning Systems: Inspect wiring connections at the HVAC units, both indoor and outdoor. Look for frayed wires, loose connections, and damaged insulation. Ensure the disconnect switches are in good working order. Test the starting capacitors and compressors for proper operation. Clean condenser coils for efficient heat transfer. Consider a megohmmeter test to evaluate the insulation integrity of motor windings.
• Transformer Inspections: Check transformers for oil leaks, overheating, and proper ventilation. Ensure the cooling fans are functioning correctly. Verify the transformer's nameplate rating is adequate for the building's current and projected load. Infrared thermography can be invaluable in identifying hot spots indicative of insulation breakdown.
• Emergency Generators: If the building has an emergency generator, perform a thorough test to ensure it can handle the increased summer load. Check fuel levels, battery condition, and automatic transfer switch (ATS) operation. Schedule preventative maintenance to address any identified issues before they become critical.
• Lighting Systems: While AC dominates summer demand, lighting still contributes. Consider retrofitting older, less-efficient lighting systems with LED alternatives to reduce overall energy consumption and heat generation.

Load Calculations and Capacity Planning

Review the building's electrical load calculation to ensure the existing service and distribution equipment can handle the anticipated summer demand (NEC 220). Pay particular attention to the air conditioning load, as it often represents the largest single load. If the existing capacity is insufficient, explore options such as load shedding, energy-efficient upgrades, or even upgrading the service entrance.

Grounding and Bonding Verification

Proper grounding and bonding are essential for safety and equipment protection, especially during periods of high electrical load (NEC 250). Inspect grounding electrode conductors, bonding jumpers, and equipment grounding conductors for corrosion, looseness, and proper sizing. Verify the continuity of the grounding system using a low-resistance ohmmeter.

Surge Protection

Summer thunderstorms often bring power surges that can damage sensitive electronic equipment. Install or upgrade surge protective devices (SPDs) at the main service entrance and at critical sub-panels to protect against transient voltage spikes. Ensure the SPDs are properly sized and installed according to the manufacturer's instructions.

Tenant Coordination

Communicate with tenants about energy conservation strategies and potential load restrictions during peak hours. Encourage them to avoid using non-essential electrical equipment during the hottest part of the day. Consider implementing demand-response programs to incentivize energy reduction.

Leveraging Ask NETA for Summer Readiness

Preparing commercial buildings for the summer cooling load requires a keen eye for detail and a solid understanding of electrical systems. Ask NETA can be a valuable tool in your arsenal. Use the app to quickly access NEC code references related to load calculations, overcurrent protection, and grounding requirements. Troubleshoot common HVAC electrical problems with step-by-step guides. And, of course, document your inspection findings and maintenance activities within the app for easy reference. Stay ahead of the summer surge – download Ask NETA today and be prepared!