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Pulling off an electric meter, San Miguel de Allende CFE employee (C) Daniel Friedman at InspectApedia.comElectric Meter Burn-Up Case Report
Overheated aluminum-to-copper connector in meter base

Loss of electrical power in half of a home traced to electric meter damage:

This article describes the loss of power in one side of an electrical panel due to an overheated connection in the electric meter base.

The electric meter itself burned and parts of its main electrical power connectors melted (photo above) principally because of a poor copper-to-aluminum wire connection in the meter base.

Photo at page top: an electrical utility worker from CFE is removing the electric meter to diagnose why electrical power was lost in one half of the electrical panel for this building.

This article series also discusses the visual inspection of electrical meters & meter bases & explains how to estimate the electrical service size, (or "electrical power" or "service amps") at a building by visual examination of the service entry cables, electric meter and meter base, electrical service panel, main switch, & other details.

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

Aluminum-to-Copper SEC Connection Leads to Electric Meter Burn-Up Failure

In a case similar to the U.S. electric meter burn damage reported by a California reader at ELECTRIC METER ARC BURN POWER LOSS, below I illustrate a wiring connection overheat that resulted in melting electric meter parts and loss of electrical power in one side of the electrical panel of a home in central Mexico.

Burned under-side of an electric meter following an overheated aluminum SEC connector (C) Daniel Friedman at InspectApedia.com

A call to the utility company brought service workers who quickly found the problem. Here are the electric meter and electric meter base showing that the meter and meter base connectors had burned and melted.

Electric meter base burn damage following an overheated Aluminum SEC connection (C) Daniel Friedman at InspectApedia.com

When electrical power was lost on some of the circuits in the home, a simple digital VOM test in the electrical panel found that all of the power on one side of the electric panel was off.

This electrical panel is supplied by two separate 120VAC electric meters, each providing power to half of the panel and together providing 240VAC power.

Dual service electric meters powering an electrical panel (C) Daniel Friedman at InspectAPedia.com

The dual-service dual-meter system is used in cities where electric utility rates are set in plateaus of usage. Splitting electrical use across two billing accounts can, in that case, reduce the total electrical utility bill. It also meant that when the meter failed, only half of the home's electricity was lost.

Below my photo shows the burned, melted electric meter base connector parts that were removed from the meter base during repairs.

It appears that the aluminum SEC wire, connected also to a copper wire that ran from the meter base inside to the electrical panel, overheated, leading to arc burning and ultimately melted connections.

Burned and melted electric meter base parts probably due to a poor aluminum-to-copper meter wiring connection (C) Daniel Friedman at InspectApedia.com

CFE workers take care to tighten the electrical connectors but they do not use an anti-oxidant on the freshly-stripped aluminum conductor.

I suspect that the connector joining the aluminum SEC, the copper feed wire between the meter base and the electric panel, and the connector itself all overheated to cause melting and arc-burning until the connection failed completely.

Below: The CFE worker is installing a new meter base connector into the existing meter socket. You can see the second electric meter of the pair at the left in this photo.

Installing replacement connector in a damaged electric meter base (C) Daniel Friedman at InspectApedia.com

Luckily buildings in this local are typically constructed of adobe or concrete. When an electrical connector or wire overheats, the most common experience is a loss of electrical power rather than a catastrophic building fire. In a wood-framed structure or where combustible materials are close to the overheating components, the fire risk would probably be greater.

In any event possible failure and electrical shock hazards remain when electrical components fail.

 




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Reader Comments, Questions & Answers About The Article Above

Below you will find questions and answers previously posted on this page at its page bottom reader comment box.

Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

Question: bad lug in the meter pan ?

My electrical company said that there was a bad lug in the meter pan but I didn't actually see it.

Do you have information at InspectApedia.com about how to detect or diagnose a bad electric meter connection that might cause flickering lights or intermittent power loss?

Thanks! [paraphrased by editor] - Anonymous by private email 2020/03/04

Reply:

You might see flickering lights or you might lose power but visual inspection is really what's needed. The electrician will look for a bad connection that's loose, corroded, or otherwise damaged and she may also check for damaged service entry wiring.

Reader follow-up:

Thanks! Is there a good resource where I can find an electrical contractor who specializes in lugs? Or can a general electrician do the job?

Reply:

Any licensed electrician who installs electric meters and panels can do what you need. 

Send me photos of what you find and let me know what you're told and I can comment further. 


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