Sunday, October 13, 2013

Settling soils can create short in electric meter box

We've lived in the same house for over 20 years. This neighborhood is well-known for its expansive soils and bentonite clay. Real estate offices write about it for home buyers who are new to the area (example here). Over the past few years, we've been going through a dry spell. This causes these soils to shrink. Our garage and driveway have sunk over four inches, causing us to have them mudjacked. I've got multiple photos of that process, but since the focus of this post is the electric meter box, let me show a photo of how I knew that the soil was sinking relative to the house:


See where the paint on the conduit stops? That's four to five inches from the ground. That's a pretty good indicator that the ground is sinking relative to the meter box, and that's not a good thing. So on August 18, I called Xcel, who is my electric provider. I asked them to come and check my meter box. Within a couple of weeks, I got a call from the gas meter people stating that they would come by to check that meter. I said that they were welcome to, but I was more concerned with the electric meter box. Evidently they came, found nothing wrong with the gas meter, and went on their way. 

On October 5th, I saw an Xcel electric truck pull up in front of my house. The tech said that she was in the neighborhood and asked if I still wanted my meter box checked. Yes, please. She said she would have been by sooner, but she'd been working many extra shifts due to the 1000-year flood that we had the second week of September.  So we went back and had a look. She pulled the meter and then opened the box. Interestingly, one of the feed cables had settled and was in contact with the box -- which isn't good. Here's a shot of the "as-found" condition:

In fact, the cable the tech's glove is on has pulled down so much that it is in contact in two places; the upper right meter contact, and the cable guide to the right.

Ah, so I was right: it did need to have an extension spliced in to relieve the tension and make sure that the cable was not touching the contact or the guide.  I was happy that I hadn't called for nothing.  It turns out that the cable clamp screws were in very tight, so I volunteered to try to loosen them.  She reminded me that all the cables were live, so please don't slip and get into some voltage.  Er, thanks, I guess.  Luckily, I got both screws cracked loose with no mishaps or slippage.  Whew.

The tech then cut out a section of cable and prepared to spliced in an extension.  Evidently the cable was worse than it originally looked:


Yes, cable was visible through the insulation. It happens that there is a clear layer of tape between the rubber insulation and the cable. That's all that was preventing a major short in the box.

If I hadn't called and the soil had continued to settle just a little bit more, then a major short would have occurred. That causes a lot of heat which can easily lead to a fire. As a firefighter, I've been to fires in my neighborhood due to exactly this cause. My meter box is mounted on brick, so I was more safe than houses where the box is mounted directly to flammable siding. But these kinds of shorts can also cause nasty surges and spikes, and wreak havoc on expensive electronics like big-screen TVs, computers, audio systems, and the like.

Moral of the story: if you see evidence of the soil setting down from your meter, call your utility and have it checked. It may save your electronics at a minimum, or a devastating house fire. Be safe out there!

2 comments:

  1. This just happened to our rental house. We DID get the short (only way we realized it) and the electrician said we were lucky we didn't have a fire. I was totally unaware of this as a potential issue for homeowners - glad to see you've posted about it!

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  2. I'm glad that you didn't have a fire! Sorry that you had the issue, though.

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