Cold weather arc flash due to condensation?

[drbond24]

This article is circulating around my work. Does anyone know any more about this? We have some doubts about it being true, but can't find any more information about it.



Thanks

 

[sameguy]

Looks bad, I would have stopped working and gone to the hospital. Facilities could get a new elec. to finish.

 

[kwired]

The guy decided his PPE was compromised and chose not to use any PPE.

I would also guess design of the meter would have an impact on how likely this might happen to the meter in that situation.

 

[Sahib]

Another mistake he did was holding the meter in his hand while taking measurement: he should have kept it separate from him.

 

[iceworm]

Discussion limited to cold weather causing condensation INSIDE of electrical equipment. Not discussing if the incident is true or not. Following is from direct experience with cold weather, interior of Alaska, -35F and colder, winter norm.

The condensation forms on (and inside if there are vents) the equipment when the cold device is brought inside.

Cold air is extremely dry - very little moisture is solution. Cold soaked device brought inside. Inside air is warm and contains quite a bit of moisture. Warm air gets next to cold device, air temp drops, moisture comes out of solution as condensation on device. It is a problem for bringing consumer electronics inside after transporting in the back of the truck. (yeah, we all drive trucks - looks like a redneck convention)

Most meters are some what sealed. Unless the warm, moist air can get inside of the meter, there won't be any condensation inside.

Got a job. Looks like a couple of week. See all later. Merry Christmas

the worm

 

[drcampbell]

It certainly seems plausible enough. If the meter were stored in a warm place for a long time, water vapor could have migrated in. When the temperature inside the meter dropped, the water vapor would condense into water droplets, which could have initiated an arc flash inside the meter.

It's also plausible that something completely different initiated this mishap, such as a multimeter with "amps" mode selected, or using a meter beyond its limits. (attempting to measure a 4160-volt circuit with a 1000-volt meter, thinking it was a 480-volt circuit, for example)

A safety voltmeter might have prevented this. With a 1 MΩ current-limiting resistor in each lead, there would never be enough current to sustain an arc.
https://www.tegam.com/shop/electrical-safety/110a/110asafety-voltmeter-cat-iii-and-cat-iv/

 

[kwired]

It's also plausible that something completely different initiated this mishap, such as a multimeter with "amps" mode selected, or using a meter beyond its limits. (attempting to measure a 4160-volt circuit with a 1000-volt meter, thinking it was a 480-volt circuit, for example)

Kind of something I was thinking also. Take a small plastic box and fill it with water, then bring two leads with 600 volts or less applied into that box, chances are it draws less than an amp in most instances. Contaminants in the water is what will vary the results.

 

[drbond24]

It's also plausible that something completely different initiated this mishap, such as a multimeter with "amps" mode selected, or using a meter beyond its limits. (attempting to measure a 4160-volt circuit with a 1000-volt meter, thinking it was a 480-volt circuit, for example)

This is what I was thinking also. However, some of the other comments say the condensation theory is plausible...I was not sure of that.

Some of the comments on the original Facebook posting this story came from pointed out that the burns are on the back of his hand. If the injuries are supposed to have come from the meter exploding in his hand, the burns would be on his palm. However, if the meter somehow initiated a flash from whatever equipment he was measuring then the burns are where they should be.