How to Safely Replace Electrical Panels in Commercial Buildings

Overview of Replacing Electrical Panels

Replacing the electrical panel in a commercial building is a complex and potentially dangerous project that requires careful planning and execution. As the licensed electrician taking on this job, my foremost priority is to ensure the safety of myself and others while upgrading the electrical service.

While daunting, with proper precautions and attention to detail, I can successfully replace a commercial panel without injuries or damage. The key is understanding the scope of the project, having the right tools, and following essential safety protocols throughout the process.

Determining Why the Panel Needs Replacement

Before beginning any work, it's crucial to fully evaluate the existing electrical panel and determine precisely why a replacement is necessary. There are several common reasons for replacing a commercial panel:

• Insufficient capacity - As usage needs grow, the amperage or number of circuits in the original panel may no longer be adequate. Upgrading to a larger panel provides more breaker spaces and capacity.

• Old or faulty equipment - Outdated panels or breakers that are no longer up to code or functioning properly need replacement for safety. Faulty breakers that trip excessively or panels with damaged enclosures present hazards.

• Safety upgrades - Improving system safety is a priority. Newer commercial panels offer advanced protective technologies like arc-fault or ground-fault circuit interruption. Replacing obsolete panels enhances safety.

• Damage from events - Damage from electrical surges, fires, floods or physical impacts can compromise panels and electrical systems, necessitating replacement.

Thoroughly assessing the status, condition and deficiencies of the existing panel is essential to justifying its replacement and specifying new equipment.

Selecting the New Commercial Panel

The needs of the specific commercial facility dictate the optimal panel specifications:

• Amperage rating - Select a panel rated for at least the calculated load but with room for growth. For large facilities, 800A or 1000A panels may be required.

• Voltage - Most commercial buildings utilize 240/120V power. Verify voltage before specifying the new panel rating.

• Phase - Match the existing phase, typically single or three-phase power. Panel amperage capacities vary based on phases.

• Circuit breaker type/capacity - Select breakers to match building needs - standard, GFCI or AFCI protection. Specify breaker amp capacities and quantity.

• Enclosure type - Indoor panels should be NEMA 1 rated. For outdoor or wet areas, choose weatherproof NEMA 3R enclosures.

• Extra spaces - Include 20-40% spare breaker capacity for future expansion.

Choose reputable brands like Square D, Eaton, Siemens or GE for proven reliability. Commercial-grade panels are most suitable for the demands of business settings.

Proper Planning and Preparation

Replacing a commercial panel requires extensive planning and preparation for a smooth, problem-free process:

• Obtain necessary permits and have inspections scheduled in advance with the local building department.

• Turn off and verify electrical supply is de-energized to the existing panel before starting work. Lock out/tag out procedures are vital.

• Carefully review the architectural plans and electrical diagrams for the building to understand the full scope of work.

• Inspect the existing wiring to ensure it is adequate and up to code. Replace undersized or damaged wires as needed.

• Obtain the new replacement panel and all needed materials - breakers, connectors, conduit, wire, etc.

• Arrange any necessary equipment rentals, such as lifts or cranes to access overhead panels.

• Schedule any required professional assistance from additional electricians or other tradespeople.

• Contact tenants to provide advance notice of power interruptions during the replacement process.

Thorough preparation is key to maximizing workflow efficiency and avoiding costly delays or shutdowns during the panel swap.

Step-by-Step Panel Replacement Process

Once fully prepared, I take the following steps to safely replace a commercial panel:

1. Disconnect and Remove the Old Panel

• Shut off the main breaker and verify power is off with a non-contact voltage tester.
• Disconnect all wires from breakers and label connections for the new panel.
• Remove mounting screws or bolts and take the old panel off the wall.

2. Install New Panel Enclosure

• Position the new panel enclosure and attach securely to the wall with appropriate fasteners.
• Attach the grounding wire to the panel case.
• Anchor the panel properly if in seismic zones.

3. Connect Wiring to Circuit Breakers

• Bolt down the new main breaker and wire the main feeds.
• Install each new circuit breaker in order and terminate labeled wires from the old panel.

4. Verify Proper Functionality

• Torque all connections to spec and double check wiring.
• Re-energize the main breaker and test lights/outlets circuit-by-circuit.
• Use a multimeter to verify proper voltage.
• Make any final adjustments and confirm full electrical service restoration.

5. Clean Up and Documentation

• Dispose of/recycle the old panel properly.
• Clean the jobsite thoroughly and finish any patching/painting.
• Complete all permit sign-offs and provide updated as-built diagrams.

Following meticulous protocols for each step minimizes the safety risks and potential for errors. I allow plenty of time so that I can work methodically without rushing.

Critical Safety Precautions

Safety is paramount when undertaking panel replacements in commercial facilities. I always adhere to required electrical safety procedures:

• Use proper PPE including arc flash safety equipment as indicated by hazard analysis. Face shield, gloves, FR clothing provide protection.

• Employ lock out/tag out procedures and verify de-energization before working. Prevent accidental re-energization.

• Exercise extreme caution when handling live parts. De-energize circuits whenever possible.

• Check for voltage in wires, even if circuits are off. Cap all wires until connections are finished.

• Keep flammable materials away from work area to prevent fire hazards.

• Maintain a clean workspace free of debris and tools that could cause slips, trips or falls.

• Follow OSHA and NEC safety standards at all times to reduce risk.

• Focus fully on the work without distractions. Rushing leads to mistakes.

Staying alert and adhering to electrical safe work practices prevents injuries and accidents on the job.

Conclusion

Upgrading commercial electrical panels requires extensive expertise and diligence. As a licensed electrician, I have the knowledge to systematically plan and execute panel replacements while prioritizing safety. Key steps include assessing why an upgrade is needed, selecting ideal equipment, proper planning and preparation, methodical installation, testing and inspection, documentation, and rigorous adherence to electrical safety protocols throughout the process. With patience and care, electrical contractors can safely provide businesses with upgraded panels that meet their evolving electrical demands.