spraying contact cleaner while it's Live

[g-and-h_electric]

Hey guys..... I know this is a little off topic, but the flammable propellants in aerosol cans brought a new hazard to mind. The "new" environmentally friendly refrigerant used in refrigerators and freezers is either propane or butane based (I forget which). How is this safe at all????

I do refrigeration work for the shop that employs me, and saw the labels.

Just an FYI, nothing more from me..... too hot in Chicago to complain!


Howard

 

[garbo]

I really only use that kind of stuff to clean out gunk and dirt that is binding the mechanical operation. of contacts

Contact cleaner from the early 1980's had freon as the propellent and mechanics in our shop used it as a degreaser. First the only sold it to electricians then they made them replace the Freon with guess cheap compressed air.

 

[Joethemechanic]

Contact cleaner from the early 1980's had freon as the propellent and mechanics in our shop used it as a degreaser. First the only sold it to electricians then they made them replace the Freon with guess cheap compressed air.

At least they didn't replace it with propane, like they did in hairspray

 

[nascaraddict20]

Contact cleaner on live circuits is for folks who don't really want to see tomorrow.

 

[hbiss]

The "new" environmentally friendly refrigerant used in refrigerators and freezers is either propane or butane based (I forget which). How is this safe at all????

Non-odorized propane. It's safe for the environment (you can just vent it instead of recovering it) but you better drag it outside before you do. Fortunately, the refrigerators that use it use very little compared to one that uses Freon so there isn't much danger. So far, refrigeration equipment that uses propane is limited to the commercial market but in Europe they have used it in everything for many years with no issues.

-Hal

 

[mtnelect]

Refrigerants rated by ASHRAE
1) R-22 is heavier than air and displaces oxygen. That is a problem if there is a leak, and the compressor is in a basement.
2) R-22, R-134A & R-410A are rated "A" (non-toxic).
3) R-454B is replacing R-410A and is rated "2L".
4) While HFCs are rated as a 1 other very flammable refrigerant(s) like Propane (R-290) are rated at a 3. The thought of working with a flammable refrigerant deters a lot of technicians and contractors from using these newer HFO refrigerants.

 

[Hv&Lv]

https://www.chemtronicseu.com/content/msds/TDS_ES1605.pdf

Dielectric strength of 44kV
We use this with power on

 

[LarryFine]

"Pow-R-Wash PR is a plastics safe contact cleaner that removes oxides and other soils on de-energized equipment."

"Flammable — Do Not use near sources of ignition or energized equipment."

"Odor Mild Ethereal" - It smells slightly unworldly?

 

[Hv&Lv]

"Pow-R-Wash PR is a plastics safe contact cleaner that removes oxides and other soils on de-energized equipment."

"Flammable — Do Not use near sources of ignition or energized equipment."

"Odor Mild Ethereal" - It smells slightly unworldly?

Now you got me wondering…

I’ll check with the guys and see which one they are using. We have a cleaner that is applied from a sprayer adapter on a long stick and we use it to spray 25kV substation switches. I know pow-r-wash was on their truck at one time, I “snagged” a can and it’s in my shop..

Anyone remember the Bill Elliot commercial for oil filters?? “I snag ‘em from the shop”.

 

[winnie]

The "new" environmentally friendly refrigerant used in refrigerators and freezers is either propane or butane based (I forget which). How is this safe at all????

I have methane going into my kitchen, controlled by valves that kids can reach.

Propane and isobutane as refrigerants are not as safe (flammability wise) as the HFC and CFC refrigerants. But the risk is manageable.

I'm comfortable with the tiny quantities used in hermetic systems like small fridges. I don't think I'd be comfortable with 5-10 lbs in a split system connected to ductwork.

I think I'd prefer using propane and adding complexity for fire prevention to using chemically more complex refrigerants. CO2 as a refrigerant is pretty nice but comes with a severe complexity cost if you go above its critical point. Also a good propellant except for much higher pressure.

 

[kwired]

What is the voltage of the float switch?, You also have to take into account if the spray is conductive.

I was going to mention I was maybe more concerned about whether it is conductive than if it is flammable.

If it ignites it will only burn whatever you sprayed, as long as nothing else easily ignitable is in the vicinity. If it is conductive you have shock or even arcing to other items of different potential to take into consideration.

 

[Besoeker3]

Contact cleaner on live circuits is for folks who don't really want to see tomorrow.

Totally agree.

 

[drcampbell]

... "Odor Mild Ethereal" - It smells slightly unworldly?

It smells sort-of like ether.

 

[ptonsparky]

Contact cleaner on live circuits is for folks who don't really want to see tomorrow.

Especially if they cycle it a time or two.

 

[garbo]

Non-odorized propane. It's safe for the environment (you can just vent it instead of recovering it) but you better drag it outside before you do. Fortunately, the refrigerators that use it use very little compared to one that uses Freon so there isn't much danger. So far, refrigeration equipment that uses propane is limited to the commercial market but in Europe they have used it in everything for many years with no issues.

-Hal

The two large research buildings that I worked at had probably over 200 ultra low temperature freezers that used two refrigerant compressors. The second compressor used a blend of refrigerant but also flammable propane. 15 years ago heard they cost over $10,000 each for maybe 16 to 20 cubic feet of storage space. One research scientist told me he had samples over 15 years old in some of these freezers. My wife's aunt had a refrigerator from the 1930's and when she moved back I the 1970's the moving company refused to move it because the refrigerant was extremely poisonous. Think the freezer only held one ice cube tray.

 

[mtnelect]

Sounds like R-717 Ammonia, toxic and flammable.

 

[drcampbell]

Dichloromethane (CH2Cl2, aka. "Refrigerant-30", aka. "methylene chloride", aka. "paint remover") was popular at the time.