Mike Dolt Enterprises
Mike Dolt Enterprises
User: Doc13067, Location: Bucks County/Philadelphia, PA USA
Asked on: Wednesday, June 2, 2021 at 9:41 pm EDT
Answered on: Thursday, June 20, 2024 at 11:43 am EDT
Question: I just looked at a job for installing mini splits in a modular home. I saw a Siemens 200A panel that looked about 20 years old with 4 vacant spaces. Just to make sure, I took the cover off and found service wires that are way too small, or so I thought. I didn’t have much time and will go back, but what I saw were aluminum wires that were definitely not 4/0. The panel had an inspection sticker on it so I’m baffled. These wires were 2/0 at best. Has anyone ever seen this? Is there something I’m not aware of or is this a major problem....
Possible Explanations
Aluminum Conductor Material
Aluminum conductors are typically smaller in diameter than copper conductors for the same amperage rating. This is because aluminum has a lower conductivity than copper.
Upgraded Service
It's possible that the service wires were upgraded to aluminum at some point in the past. Aluminum wiring was commonly used in the 1960s and 1970s, although it has since been phased out due to safety concerns.
Special Permission
In some cases, aluminum service wires may be allowed by special permission from the local electrical inspector. This could be due to the difficulty of accessing the service entrance or other factors.
Safety Concerns
If the service wires are indeed aluminum and undersized, there are several potential safety concerns:
Overheating
Undersized wires can overheat, leading to insulation damage and potential fire hazards.
Connection Problems
Aluminum wires can be more difficult to connect securely than copper wires. This can lead to loose connections and increased resistance, which can also cause overheating.
Corrosion
Aluminum wires are more susceptible to corrosion than copper wires. Corrosion can weaken the wires and increase the risk of failure.
Recommendations
Confirm Wire Size
Return to the site and measure the service wires accurately using a wire gauge or micrometer.
Research History
Contact the local electrical inspector to inquire about any special permissions or previous upgrades to the service entrance.*
Consult with a Licensed Electrician: If the service wires are confirmed to be undersized, consult with a licensed electrician for further evaluation and recommendations. It may be necessary to upgrade the service entrance to meet current code requirements. Flag for review