Chemical vs water fire extinguishers

[dadster4]

How do firemen not get electrocuted?

First thing firemen do is pull the meter on a house fire or disconnect feeds if possible on bigger structures. Damaged/burned electrical systems are a SOURCE of new fires elsewhere in the building. They also wear fire rated clothing, gloves, and boots...as I do at work for safety reasons.

 

[aczlan]

How do firemen not get electrocuted?

They shut down power first...

Aaron Z

 

[RNeumann]

How do firemen not get electrocuted?

We try very hard not to squirt water on energized electrical equipment or fires!

Once the electricity is turned off we will extinguish the fire. Typically with water. Although we have some tricks for molten metal which don’t respond well to water.

With regards to voltage- saying one would squirt water on anything under say 600v is not exactly sound. As an example the ignition on your car is typically 10,000+volts and we use water on that all the time.

This thread started on a far different topic. Bottom line for me is if I had an extinguisher on a tractor or near an outdoor welding operation I’d go for the water extinguisher with some soap in it. 99/100 fires will be in the vegetation and the water will do OK on the 1/100 vehicle type fires. In my shop and house I keep an ABC dry chem- 2A10BC will put out a lot of fire. If I saw an electrical fire in my home or shop I’d shut the power off and use a dry chem. It was outside my home (transformer, power lines etc) and I wasn’t working, I’d move away, call 911 and drink a beer while someone else dealt with it. If I was on duty I’d keep folks away until the utility had the power off. You don’t extinguish electrical fires.....you extinguish the results of an electrical fire.

 

[leonz]

I keep hoping that they bring back water acid foam fire suppression using vinegar and baking soda to make foam instead of sulfuric acid. It would certainly make blanketing lines of fire easier to coat everything with less water.

Metering two or three hundred gallons of strong cider vinegar or white vinegar and a premixed water solution with baking soda would work well with an eductor nozzle pulling the vinegar out of the tank to mix the two components together prior to pumping it out of the 2 inch hose line.

 

[mxm3904]

Look up FEDCO poly fire tank. It's a 5 gallon backpack type tank that hold 5 gal of water with a manual pump. I got one after I had a field catch on fire and it took 30 min for the fire department to show up. It's made for fighting brush fires. Seems to work good on the test fires I used it on.

 

[Mace Canute]

Since the subject of using water on an electrical fire has come up...as an old retired power lineman I've done quite a bit of washing dirty insulators on energized 25 kv, 72 kv and 138 kv power lines. The insulators get contaminated from dust in the air and start to leak a bit of current to ground and if the leakage gets high enough, the current can set fire to wood poles and or arc over and trip the circuit on steel poles. Along highways is the worse because of the salt used. When it dries up the cars pulverize it and it contaminates quite a distance each side of the highway. Once it builds up on the insulators a heavy dew or very light rain makes it very conductive. Usually rain washes it off fast enough that it's not a problem.

Anyways, we used a pressure pump that would maintain at least 1000 psi with a 1/8" orifice. (here's bigger ones out there too.) Heavy copper ground from the nozzle all the way along the hose to the pump & trailer and then everything was grounded. We used deionized water from the power plant and deionized water is a very very poor conductor.

The stream of water through the round orifice would break up into small droplets so it wasn't a solid stream of water like you sometimes see with low pressures and this was the primary safety feature of the washer and we always checked the pressure while spraying to make sure it was high enough to guaranteed the formation of water droplets.

Sometimes no matter how we approached the job, as soon as we hit the insulator with water it would flash over especially in one customer owned 72 kv substation. They didn't want to shut down the plant so we would try to wash the insulators while energizes and BANG! Flashover and their breakers would trip. After awhile they listened to us and shut their plant off first and isolated the line before we started to wash.

 

[MickeyDBC]

Back when I was young and everyone smoked and tossed the butts out the window we used to put out a lot of roadside fires with a wet feedsack. We would leave a couple of them in a 5 gallon bucket full of water in the back of the truck and just beat the fire out. Between that and a shovel you can put out a lot of fire.

 

[ruffdog]

Back when I was young and everyone smoked and tossed the butts out the window we used to put out a lot of roadside fires with a wet feedsack. We would leave a couple of them in a 5 gallon bucket full of water in the back of the truck and just beat the fire out. Between that and a shovel you can put out a lot of fire.

That is a good idea! Always ready and never needs recharging.

 

[Mace Canute]

Back when I was young and everyone smoked and tossed the butts out the window we used to put out a lot of roadside fires with a wet feedsack. We would leave a couple of them in a 5 gallon bucket full of water in the back of the truck and just beat the fire out. Between that and a shovel you can put out a lot of fire.

I remember when I was a kid and the old farts would love to burn off sloughs in the spring. They would use a pitchfork with a jute gunny sack tied around the tines and soak that in water when they had to do some judicious control of the grass fire. It worked quite well as I recall.

 

[cqaigy2]

I remember when I was a kid and the old farts would love to burn off sloughs in the spring. They would use a pitchfork with a jute gunny sack tied around the tines and soak that in water when they had to do some judicious control of the grass fire. It worked quite well as I recall.

Still a good method. That water goes a long ways, though i imagine sometimes you wish you had a longer handle.