Ground Transformer safety versus pole transformer

[honda1998civic]

So I’m looking to build a new home and we are discussing the in ground power to the house meter but I’m just curious about the safety of Transformer being on the ground. When I hear a transformer blow that is on the pole it is very loud but I have less concern because it is up in the air. So should I be concerned with transformer on the ground or is there no arc flash that occurs?

 

[Showkey]

All the power lines ( underground) and transformers on on the ground never seems to a concern in our area.

Its preferred as the storms rarely knock the power out now and 4-5 years ago it was considered a huge costly upgrade. Think underground benefits of lower maintenance and no outages pay for those higher costs.

Then there’s benefit of not seeing the poles.

 

[Stuart in MN]

I wouldn't worry about it. While the terminals are exposed on pole mounted transformers, the terminals on pad mount transformers installed at grade level are inside a metal enclosure. That enclsoure should provide protection in the event of an arc flash (unless you run into it with a truck or something, and then you'll probably have other things to worry about.)

 

[BillK]

My neighborhood is getting close to 50 years old. All of the power is in the ground and the transformers are on the ground. I have lived here since 1978 and the transformer in front of our house is the original one. No issues. I think a few have failed over the years but it has never been a problem.

 

[mike93lx]

I would never choose above ground distribution when in ground is an option.

 

[RPH]

Only problem I had with a ground transformer was in Florence, Ky. They built a freeway off ramp and stick the transformer in the middle of the grass circle. It ended up being a low spot. Had the 100 year storm and that xformer blew up. Blackout at the plant for a couple days.

 

[mikedodge]

Lots of transformers on the ground. The only risk is morons running into them. Everything is above ground in our neighborhood and never had a transformer blow.

 

[walta]

I feel the below ground service is much more reliable.

Yes transformers do fail from time to time but I see no reason to believe one is more or less likely to fail.

When I built my home they asked where I wanted the new transformer and I pointed to a spot and that is where it sits. It sits about 25 feet from the garage sometime it feel uncomfortably close. The only real risk I see is fire and that seems small at that distance.

Walta

 

[nadogail]

Ground Mounted, properly engineered, is better.

 

[wyliesdiesels]

Are you worried that a ground transformer will explode? What else safetywise could you be worried about?

 

[83VillageRepair]

So I’m looking to build a new home and we are discussing the in ground power to the house meter but I’m just curious about the safety of Transformer being on the ground. When I hear a transformer blow that is on the pole it is very loud but I have less concern because it is up in the air. So should I be concerned with transformer on the ground or is there no arc flash that occurs?

The noise you hear on overhead transformer outage is the expulsion fuse (google it) blowing, not the transformer blowing. It sounds like a shotgun shell going off and is designed that way to extinguish the arc.

Underground services are inherently more reliable but when they have an outage it will be much much longer. So fewer longer outages for underground and frequent shorter outages for overhead.

Both are equally as safe.

Wade

 

[engineer2]

We have underground power lines in our subdivision. A lot nicer than overhead lines.
It's been very reliable after the replaced a bad transformer and fixed one of the underground lines that was damaged from water infiltration.
On some streets they put the transformers in the front yard, which is ugly.
Over the years most of the transformers have tilted or settled part way into the ground. Not sure if the power company takes steps to prevent that.

Every few years a fence installer hits a power line. Even though line locations get paint marked, people make mistakes:
Hear a big zap, lights out, people yelling, Com Ed arriving later to fix the damage. I was told the lines are supposed to be 6 feet deep and fence posts around here are put in 4 ft deep, so something's not right. Maybe the lines are shallower near the transformer.

 

[MBfreak]

My input from having worked with HV, MV and LV power systems for +50 years. Even once in the US, HVDC link on the west coast.
MV and LV distribution will be very much more reliable with underground ( > 1,6 m deep) cables and nicely designed prefab buildings for the transformers and switchgear. And of course the MV system topology shall be ring so that a single MV cable fault can be disconnected in a matter of minutes and service restored.
There are several posibilties to also do likewise on HV installations up to 170 kV, quite simple.
On 245 kV and above cables and GIS indoor are common in many countries, google ie St Johns Wood 420/275/145 kV substation in London UK.

Ola

 

[rburke65]

I think you’d have nothing to worry about with the electrical feeders under ground. Good luck.