Mike Dolt Enterprises
Mike Dolt Enterprises
User: fireshaper, Location: Australia
Asked on: Sunday, June 15, 2025 at 8:48 pm EDT
Answered on: Sunday, June 15, 2025 at 9:34 pm EDT
Question: Hi everyone,I’m seeking insight into a mass electrical outage that occurred at my commercial premises, a hot yoga studio located in Australia—on May 28, 2025. The incident resulted in a complete loss of power to my unit and significant damage to equipment. I’d greatly appreciate expert perspectives on what might have caused the issue and whether liability could fall on a builder working on the roof at the time.Background:My building is a single-level commercial complex with 7 units, all connected to a main switchboard at the opposite end of the property from my unit.I have one main panel and one subpanel inside my unit.The subpanel feeds 24 Far-Infrared heating panels, wired as 2 panels per circuit (12 circuits total).All equipment was functioning normally in the early morning (heating panels, AC, lights, computer).Incident:Around mid-morning, my entire unit suddenly lost power—every circuit tripped, including the main switch at the external building switchboard.At the same time, roofing contractors were replacing the metal roof across the building. They claimed to be working only at the opposite end of the building, focusing on air conditioners.My staff immediately consulted the builder, who began flicking breakers at both my internal panels. When nothing restored power, he brought in two workers and later accessed the main external switchboard.Shortly after they left, power returned to lights only. Heating panels and several devices remained non-functional. The builder had energized all the switches in my main panel and sub-panel. He then went down to the other end of the building and energized the main power switch which was in the off position (no one knows why it was off).Findings (from Licensed Electrician Contractor):All 15 sub-circuits were tested: 12 failed insulation resistance tests, with faults between active/earth and neutral/earth.11 of those 12 faulty circuits were connected to the heating panels.A total of 23 heating panels were damaged, along with a computer and 2 LED panels.They suspect a massive inrush current occurred when the builder reset the main breaker without isolating any downstream circuits.The inrush current estimate was 188A (24 x 1800W panels), which likely exceeded the breaker’s rating and triggered the damage.They concluded the most probable cause was improper energizing after an initial trip—everything was left ON during reset.No storms, grid faults, or external electrical events were reported in the area that day.
Okay, this is a complex situation with several potential contributing factors. Let's break it down, addressing potential causes and liability
Potential Causes of the Outage and Equipment Damage:
Based on your description and the electrician's findings, here's a breakdown of possible causes:1. Initial Trip Event (Unknown Cause)
The critical unknown is why the initial trip occurred. The fact that everything tripped, including the main breaker at the external switchboard, suggests a significant fault somewhere. Possibilities include:
Transient Overvoltage (Spike/Surge)
While you state no grid events, a transient overvoltage could have originated from within the building itself or even a nearby source. A sudden spike can damage insulation in multiple circuits simultaneously.
Short Circuit/Earth Fault
A single point of failure (e.g., a frayed wire in a heating panel) could have caused a short circuit or earth fault strong enough to trip the main breaker. This is less likely to damage so many circuits simultaneously but can still trigger a cascading effect.
Loose Connection/Arcing
A loose connection in the main panel or sub-panel, especially one carrying a heavy load, can arc and generate heat, damaging insulation and eventually leading to a fault. This arcing can also create voltage fluctuations that stress other components.
External Interference (Roof Works)
While the contractors claim they were only working on AC units and at the other end of the building, this is a key point to investigate. Possible scenarios related to the roof work:
Accidental Contact
Did the contractors accidentally drill/cut/impact electrical wiring within the roof cavity? Even if seemingly at the other end, wiring often runs the length of the building.
Vibration/Movement
Roof work creates vibration. This could have exacerbated a pre-existing weak point in the wiring (e.g., a loose connection or compromised insulation).
Moisture Ingress
Was there any chance of rain getting into the roof cavity during the roof replacement? Moisture can drastically reduce insulation resistance, leading to faults.
EMF Interference
Roofing Contractors equipment may have caused issues with some of the electrical wiring in the roof.2.
Builder's Actions (Improper Energizing)
Your electrician's assessment of "improper energizing" is highly plausible. The builder's actions likely compounded the initial problem. Here's why:
Resetting Main Breaker Without Isolation
Resetting the main breaker without first identifying and isolating the fault is extremely dangerous. It's like restarting a car with a known engine fire. The inrush current to all those damaged circuits likely caused further insulation breakdown and the burning out of the heating panels and other electronics.
"Flicking Breakers" Randomly
The builder's description of "flicking breakers" suggests a lack of understanding of electrical systems. This random switching could have further stressed the already damaged circuits.
Re-Energizing the Entire System
Re-energizing all circuits including the heating panels (24 x 1800W panels = 43.2kW and ~180 amps), without testing or isolating the initial problem would of placed extreme load back on the faulty circuit.
Liability Considerations
This is where things get tricky and require legal consultation. Here's a breakdown of potential liability:1.
Builders (Most Likely Liable)
Negligence
The builder's actions after the outage could be considered negligent. Resetting breakers without proper diagnostics and potentially causing further damage opens them up to liability.
Duty of Care
Builders have a duty of care to avoid damaging existing property while carrying out their work. If their roof work caused the initial outage (even indirectly via vibration or contact), they could be liable.
Breach of Contract (Potentially)
The roofing contract may have clauses about responsibility for damage caused during the works.
Workers Compensation Insurance
Check if the roofers had Workers Compensation Insurance if this can be used.2.
You (Potentially Partially Liable)
Electrical System Condition
If your electrical system was demonstrably old, poorly maintained, or non-compliant with current standards, it could be argued that it contributed to the problem. Regular electrical inspections are crucial for commercial properties.
Pre-Existing Conditions
If it can be proven that something such as moisture had accumulated in the roof before the contractor, then it could be a pre-existing condition.3.
Previous Contractors (Less Likely)
If there were previous electrical contractors who had done work on your premises, their work should be investigated and examined for any issues.
Recommendations
Consult a Lawyer (Crucially)
This situation demands legal advice from an experienced commercial litigation lawyer specializing in construction disputes and electrical damage claims in your specific Australian state. They can assess the evidence, advise on your legal options, and represent you in negotiations or litigation.2.
Document Everything (Meticulously)
Keep all documentation related to the incident, including the electrician's report, photographs, invoices, and communication with the builder. Document the builder's actions in detail (who did what, when, and where). Written statements from staff are valuable. Get a second opinion/assessment from another qualified electrician independent of the first one and the builder. This provides a check on the original assessment.3.
Investigate the Roof Work Thoroughly
Press the builder for specifics on exactly what work was done, where, and when. Request detailed diagrams or photographs. Ask the builder to provide any reports or logs of incidents that may have occurred on the day. Specifically ask questions around the moisture, wiring, and accidental contact by the builders.4.
Review Insurance Policies
Check your business insurance policy and the builder's insurance policy to determine coverage for property damage and liability. You will need to lodge a claim with your insurers.
Key Questions to Ask
To the Builder
What exactly did you do, and when? Did you notice any electrical problems before the outage? Were there any incidents (dropped tools, sparks, etc.)? Can you provide a log of the roofing process for the day?
To Your Electrician
Can you provide a more detailed breakdown of why you believe the builder's actions caused the specific damage? Can you identify the potential source of the initial fault?
To the Lawyer: What is the likelihood of successfully claiming against the builder? What evidence is needed to strengthen my case?This is a challenging situation, but by gathering thorough evidence, seeking expert advice, and understanding your legal options, you can work towards a fair resolution. Remember to prioritize safety and only allow qualified electricians to work on the electrical systems. Good luck! Flag for review