HVAC 3 phase shut off box ?

[Mech]

I was going by one of my areas dumpsters and found a large [ about 20" x 3' ] HVAC switch box .
Did a little diving , & it followed me home & got dismantled .
Always looking to add to the hardware collection - do a lot build , repair / and hardware is getting way too costly .
Assumed I would get some brass , well after taking apart the contacts knife blade had a slight yellow & a little dark color .
Scratched with a knife & see a very white / silver color .
I'm thinking a high silver content alloy ?
Any others recycled these ?

 

[Martijn]

I was going by one of my areas dumpsters and found a large [ about 20" x 3' ] HVAC switch box .
Did a little diving , & it followed me home & got dismantled .
Always looking to add to the hardware collection - do a lot build , repair / and hardware is getting way too costly .
Assumed I would get some brass , well after taking apart the contacts knife blade had a slight yellow & a little dark color .
Scratched with a knife & see a very white / silver color .
I'm thinking a high silver content alloy ?
Any others recycled these ?

Can you take a picture?

 

[kurtak]

I was going by one of my areas dumpsters and found a large [ about 20" x 3' ] HVAC switch box .
Did a little diving , & it followed me home & got dismantled .
Always looking to add to the hardware collection - do a lot build , repair / and hardware is getting way too costly .
Assumed I would get some brass , well after taking apart the contacts knife blade had a slight yellow & a little dark color .
Scratched with a knife & see a very white / silver color .
I'm thinking a high silver content alloy ?
Any others recycled these ?

What Martijn said - hard to say without pics

Kurt

 

[offtrailhiker]

Generally a high voltage contact is of a tungsten alloy. If you happen to have a melting furnace or forge toss it in. Tungsten won't melt however hot your home forge may get.

 

[kurtak]

Generally a high voltage contact is of a tungsten alloy. If you happen to have a melting furnace or forge toss it in. Tungsten won't melt however hot your home forge may get.

I don't mean to be rude here but this is a somewhat misleading post

First of all - just because they (contacts) are high voltage does not mean they will be tungsten (alloy)

It is not a question of their voltage that determines if they are made with tungsten - or other alloy

Rather - it is their "application" that determines what they are made of

Secondly - IF (the BIG IF) they are made with tungsten then they will be a "sintered" product & NOT a true alloy

An alloy is made where two or more metals are actually "melted" together making an actually "chemical bonding" of the metals with each other in "the alloy"

A sintered product is made by taking two or more metal "powders" & "compressing" them under HIGH heat & HIGH pressure so they are NOT actually chemically bonded - they are just different metals packed "very tightly" together

Generally speaking - about the "only" place you will find the "sintered" tungsten/silver type contacts is in hand thrown circuit breakers" --- such as the circuit breakers in your house hold electrical panel as well as LARGER industrial "hand thrown" circuit breakers --- these points run between 60 - 70 tungsten & 30 - 40 percent silver

These points can NOT be melted in a furnace due to the VERY high melt point of the tungsten (which why they are sintered & not a true alloy) nor can they be simply dissolved in nitric like you normally dissolve silver "alloys" --- in order to leach the silver "out" of the sintered tungsten they MUST be literally BOILED in nitric & to get ALL of the silver leached out of the tungsten it can take 24 hours to 48 hours of BOILING them in nitric

The other more/most common types of contacts are ether high voltage "magnetic disconnects" - or low voltage relays

High voltage magnetic disconnects will ALWAYS be a silver "alloy" & will generally be "about" 90% (plus) silver - these will melt in a furnace & as well dissolve in nitric like any other silver (true alloy)

Low voltage relays can be a silver alloy - or gold "plated" silver - or silver/palladium alloy - or solid palladium - or silver & other PGM alloy - or other solid PGM

There are a FEW other types of silver contacts /switches out there but they are not real common

This is why I asked for pics of what the OP has - so we can determine the "type" switch/contact he has & then determine if (worth) &/or how to process

Kurt

 

[Martijn]

Generally a high voltage contact is of a tungsten alloy. If you happen to have a melting furnace or forge toss it in. Tungsten won't melt however hot your home forge may get.

And beryllium copper is often used in high voltage contacts.

 

[anarxi]

in general, it's a completely useless and even dangerous thing in places.
it wasn't even worth raising...

although, frankly speaking,
I don't understand why you would ask a question without posting a photo.
after all, it's worth spending 15 seconds, taking a photo and posting it in your message.
using your phone.

 

[kurtak]

And beryllium copper is often used in high voltage contacts.

This is ONLY a concern in relays (whether high voltage or low voltage) where the "thin" reeds which the contact points are attached to need to "flex" to open & close the points when activated by the magnetic coil of the relay

That is "one" of the properties of BeCu - it hardens the copper such that it allows the copper to flex like a spring but also not stress crack from flexing due to its hardness --- other hardened copper alloys (such as phosphor bronze or nickel brass) tend to stress crack from flexing (if the reeds are too thin)

So they will use ether beryllium copper or beryllium bronze for the thin flexing reeds in magnetic (coil) activated relays

So BeCu is NOT a concern in contactors such as magnetic disconnects &/or hand thrown circuit breakers as the points are attached to much thicker/heavier copper/brass/bronze "solid" bus bars rather then flexing reeds

Beryllium copper is an alloy of copper plus 0.5 - 3 % beryllium & can be "somewhat" identified by eye as the copper will have a pinkish hue to it rather then the deeper red/orange of pure copper (along with its spring effect)

Beryllium bronze is an alloy of copper plus 0.2 - 2 % beryllium plus 0.2 - 2 % cobalt or nickel that has the more golden color of yellow brass (if nickel is used) or a slight blue hue (if cobalt is used)

It should also be noted here that not all the spring/reeds in relays are made of BeCu &/or Be bronze - they can also be made of phosphor bronze (CuSn) or nickel-silver (CuNiZn) (there is NO silver in this alloy it is just called nickel-silver due to its silver color resulting in the red being "bleached" out of the copper by the nickel) &/or out of spring steel --- CuSn & CuNiZn reeds in relays tend to stress crack from frequent flexing so to overcome that they will generally be 2 - 3 times thicker then BeCu or Be bronze reeds & as well the reeds will (generally) be longer &/or as well closer spacing between the points

So hopefully this will "somewhat" help to identify if the reeds in relays may - or not - be made of BeCu or Be bronze --- or made of some other copper spring alloy ------------

BeCu = very thin with a pinkish hue (color) rather then deeper red/orange

Be bronze = yellow brass color (CuBeNi) or redish with blue hue (CuBeCo) - but - also very thin

These will also have (generally) shorter reeds with a "relatively" wide spacing between points

CuSn (phosphor bronze) = yellow brass color ("may" be tin or silver plated) with thicker longer reeds & closer spaced

CuNiZn (nickel-silver - sometime called nickel brass) silver/grey color with thicker longer reeds & closer spaced & "may" (or not) be "slightly" magnetic depending on amount of nickel in the alloy

And then there are the spring steel reeds which will be very magnetic

For what it is worth

Kurt

 

[Mech]

Tried a neodymium magnet - not the slightest reaction .
Again HVAC hand operated switch box , guessing for roof top AC on a commercial building .

One item in picture was not intended - copper / brass golf tee remover from my recycle stuff

 

[Darkthirty]

Tried a neodymium magnet - not the slightest reaction .
Again HVAC hand operated switch box , guessing for roof top AC on a commercial building .

One item in picture was not intended - copper / brass golf tee remover from my recycle stuff
View attachment 66388View attachment 66389

White bronze maybe. Drip test it with nitric.

 

[snail]

White bronze maybe. Drip test it with nitric.

Most likely heavy silver plating. Hit it with a file or grinder.

 

[anarxi]

yes, the color is very similar to silver plating.
in any case, there is silver in the coating.
but there is so little of it that it is really not worth bothering about.
It would be much more valuable if they were made of copper.
but as they say: we have what we have.
free - bleach ,cottage cheese.

 

[Mech]

I did have one of the test kits - touch stone & gold , silver & platinum , but too much time [ at least a few + yrs. ] has past & the silver test chem. lost its ability.
Will use a grinder , either way it will go into my collection of future silver recovery stash .
Thanks

 

[Darkthirty]

I did have one of the test kits - touch stone & gold , silver & platinum , but too much time [ at least a few + yrs. ] has past & the silver test chem. lost its ability.
Will use a grinder , either way it will go into my collection of future silver recovery stash .
Thanks

Put a few drops of bleach on the exposed metal, black is a sign of silver

 

[Master Nater]

knife switches like these are usually solid copper ... or they could be silver or tin plating on copper. sometimes you can run into smaller knives made of brass, but usually only in smaller 30a switches. you can take a pair of pliers with a side-cutter, and cut off a small corner, or file off a corner to reveal the metal under the plating. you should clearly see the copper or brass underneath the silver or tin plating once you have exposed it. potassium dichromate silver testing solution should tell you whether you have silver or tin plating.