Okay, this is a potentially dangerous situation. You're dealing with a vandalized electrical system that you're trying to bring back online for a sale. Safety is paramount. Here's a breakdown of what you've said, and what you absolutely need to do, with a focus on safety and code compliance.

Understanding the Scope and Risks



Copper Theft = System Compromised

Copper theft is a hallmark of serious electrical damage. Thieves don't care about safety or code. Expect anything to be wrong. Just because the MDP "looks OK" doesn't mean it is.

Burn Marks = Evidence of Failure

The burn marks are critical. They indicate a fault, overload, or short circuit happened. This means insulation has likely failed, and components are damaged.

Utility Cut-Off

The utility's action is good, but it also suggests they may have concerns. Talk to them. Specifically ask why they cut power. Their reason could inform your inspection.

Missing Breakers/Feeders

This is a huge red flag. What were those feeders for? Where did they go? This needs investigation to determine the extent of the damage.

Age of Service

10 years is not ancient, but it's not new either. If the system has been abused, its lifespan is significantly reduced.

Your Proposed Actions - Evaluation



Cleaning Up

Good. This is necessary for a proper inspection.

Saving 'Fingers'

Hold off on this for now. We need to determine if the entire MDP needs to be replaced. Saving parts might be a waste if the busbars are damaged.

K/O Seals

Important for preventing debris and rodents.

Grounding/Bonding

Absolutely essential. This is the primary safety system. Verify all grounding and bonding is intact and properly sized according to code. This includes the grounding electrode system (ground rods, water pipe connection), the equipment grounding conductors, and bonding of metallic enclosures and conduits.

Ohm Out the Service

Incomplete. While checking resistance between phases and ground is a start, it's not sufficient. You need more thorough insulation resistance testing.

Preventing Energization

Good, but temporary. This needs to be a lock-out/tag-out procedure. Do not rely solely on your knowledge; use physical locks and tags.

What You MUST Do (Beyond What You Listed): A Step-by-Step Safety Plan1. STOP and Obtain Permits and Inspections

Do not proceed without consulting with the local electrical inspector. Explain the situation. They will likely require permits and specific inspections. This is for your safety and to ensure compliance. This is a commercial installation.2.

Detailed Visual Inspection



MDP and Switchgear

Remove the covers and inspect everything. Look for: Burn marks (inside and out). Arc flash damage (melted plastic, discoloration). Corrosion. Evidence of rodent or insect infestation. Loose connections. Cracked or damaged insulators. Damaged busbars (the copper bars that distribute power). Check for proper torque on all connections.

Conduits and Wiring

Trace all the cut conduits. Where did they go? What did they power? Inspect accessible wiring for damage (nicks, cuts, brittle insulation). Check conduit supports.

Disconnects

Open all disconnects and inspect for damage.

Grounding System

Visually verify the integrity of the grounding electrode system (ground rods, connections to building steel, water pipes).3.

Insulation Resistance Testing (Megger Testing)

This is non-negotiable.



Procedure

With the main breaker OFF and LOCKED OUT, and all branch circuit breakers OFF, perform megger tests:

Phase-to-Phase

Test between each phase conductor.

Phase-to-Ground

Test between each phase conductor and the ground conductor.

Neutral-to-Ground

Test between the neutral conductor and the ground conductor.

Voltage

Use the appropriate megger voltage (typically 500V or 1000V, depending on the voltage rating of the system).

Interpretation

Record the readings. Compare them to acceptable values for your voltage and wire type. Low resistance indicates insulation breakdown. Consult a qualified electrician or engineer for interpretation. Do not guess.

Important

Isolate sections of the system if necessary to pinpoint the location of the fault.4.

Continuity Testing

Verify the continuity of the grounding system. Use a low-resistance ohmmeter to check the resistance between all metallic enclosures, conduits, and equipment back to the grounding electrode conductor.5.

Ground Fault Loop Impedance Testing

Once you've restored power to a branch circuit, test the ground fault loop impedance at various points in the circuit. This ensures that a ground fault will trip the breaker quickly.6.

Breaker Testing (If Possible/Necessary)

Ideally, have the main breaker and some representative branch circuit breakers tested by a qualified testing company. They can verify that the breakers trip at their rated current. If you don't test, replace.7.

Load Calculation

Verify the service is adequately sized for the intended use of the building. Missing feeders suggest changes in the load.8.

Documentation

Keep meticulous records of all inspections, tests, and repairs. This will be invaluable for the potential buyer and for future maintenance.9.

Professional Consultation

This is also non-negotiable. Hire a licensed and experienced electrical contractor and a qualified electrical engineer. They can: Help you interpret the test results. Develop a repair plan. Ensure compliance with the National Electrical Code (NEC) and local codes. Oversee the work. Provide a written report certifying the safety and compliance of the electrical system.

Specific Answers to Your Question



Megger Test Before Energizing

YES, ABSOLUTELY. It's the minimum you need to do before the utility energizes the transformer. However, it's just one part of a comprehensive testing and inspection process.

Important Considerations



Liability

You are taking on significant liability by working on this system. If someone gets hurt or the building burns down due to a fault in the electrical system, you could be held responsible. This is why professional consultation and documentation are crucial.*

Honesty

Be upfront with the potential buyer about the damage and repairs. Disclosing this information will build trust and protect you from future liability. Provide them with all the documentation you've gathered.

In Summary:

You're facing a complex and potentially dangerous situation. Don't cut corners. Follow a systematic approach, prioritize safety, and involve qualified professionals. The cost of doing it right is far less than the cost of an accident or a lawsuit. Flag for review