conductive grease at electrical contact

Just a thought: what does the rail industry use for electric trains that have third- and fourth-rail electrical pick-up with a scrapey-shoe? Would contacting a number of urban transit systems be of value?

There is a conductive grease available for very high voltage use. It is primarily used by local electrical companies and railroads. You may want to ask them. I used at one time some grease that had silver in it, but I don't remember the name? I found it in the back of an electronics magazine.

The grease that we use on circuit breaker connections to bus bar, and any other conductive moving parts is Mobil 28, which is a red grease..

I have used both of the products below on substation switches up to 138 KV.

http://www.sanchem.com/aSpecialE.html

http://www.cool-amp.com/conducto-lube.htm

try Penetrox from Brundy.

go to http:\\fciconnect.com

search for Penetrox.

There are many such greases/fluids comertially available for this purpose. Dow makes 'silicone fluid/grease' which very popular for such application. Basically these stuff are 'die-electric'.

The main purpose of grease/oil around electrical contact is to prevent the contact heating up and prevent oxidization at high temperature which prevail there.

But Amol demands, "also the same is of conductive electrically", sounds dangerous. If this grease itself is conductive, and if get spread, then lead to short circuit/earthling etc.

But conductive grease sound interesting for some other applications…

DO NOT use silicon grease, or any other dielectric lubricant, directly on contact points. Silicon is an insulator, the opposite of a contact. Use of dielectric on the contacts will cause a high resistance connection, excessive heating, and eventual failure or fire.

Conductive grease is a specialized product designed specifically to prevent corrosion and improve conductivity of the sliding parts of the contacts themselves, making for a better connection. It is very thick, and does not flow at all. However, as you say, extreme care must be taken to ensure no conductive grease is left on the high voltage insulators. If grease does get on the insulators, it can be removed with mineral spirits.

<which we can use at the electrical contact high voltage >

Technically there are Conductors,Semiconductors and insulators. Greases cannot be the 1st and 2nd groups.Hence CAN only be insulators.

Greases do keep the environs of a wiping Contact free from pitting Oxidation. Current at any voltage is carried only by copper/alloys.

Yes Chemverse advertizes thus

<

CVC Graphikote - 66 (Conducive coating)

Dry graphite coating having controlled resistance for electrical conductivity used for corrugated boxes, plastics surfaces and components such as variable rheostats, conductive tracks, etc>

These are also greases, HENCE CANNOT CARRY CURRENT.

MM

Also at Chemverse is this product:

• SYNOL ECG - 77 (Contact Grease)
• A highly conductive electrical contact grease, compatible with metals, plastics, rubbers, etc. Suitably fortified to protect contacts against corrosion and wear. It is applicable to all types of contacts such as sliding / rotary controls, turret tuners, knife switches, bus bars, battery terminals, OLTCs, relays, contactors, etc.
• Packing : 550 ml. Aerosol

I've find the term conductive grease misleading. This one is advertised as "highly conductive". It is a spray, so if it really were highly conductive, you wouldn't want to spray it on or near switches, contactors, relays, etc.

I used to work in the coal mining industry, where cable reels were used with 990V three phase cables. The slip rings were lubed with "conductive grease" which, when sloppily applied, would span across phases -- so if it were conductive, you'd expect a big bang when the power was turned on.

Sanchem, in their lit for NO-OX-ID ASpecialE, has this to say about adding metal particles to grease, with the intent of increasing conductivity:

• Falicy of adding metals to increase Conductivity:
  Many contact greases have copper, zinc or other metals blended into a grease to increase conductivity. In a study for an aerospace company in 1985 it was concluded that putting a metal into grease does not help conductivity. In many cases it reduces conductivity. The United States Department of the Interior Bureau of Reclamation in their Facilities instruction Journal Volume 3-3 Electrical Connections for power circuits states in Sec. 6.3.2 that "Use of grease with embedded zinc particles will cause a poorer connection due to the lower conductivity of zinc".

So I agree with you that greases cannot (and generally should not) carry current. I don't know why these are called conductive greases. Do you Mukul, or anyone else here, know?

there are lots of silver / graphite based conductive fluids available for conductive track making on PCB , also oil based 3 phase starters for motors are still in use but that (oil) is not conductive only used for heat transfer and protection from oxidation.

a silicon based semi fluid with silver as conductive suppliment can be utilised, rs components may get you industrial quality conductive grease

.

Is it that you ask for grease because you want something slippery or that historically grease was used because of its impermeabiulity to water which would cause oxidation of various sorts.

If you are asking for a compound to apply to mated surfaces to protect from water or other forms of corrosion and still enable electrical continuity try this...

http://www.tefgel.com/

either tef gel or tuff gel

If you are looking at knife type disconnect switches, use Molykote 41 Grease. This grease has carbon black as a filler in that making it a silicone based conductive grease.

It maintains relatively low resistance electrical contact between sliding metal to metal contacts. This grease will prvide a continuous path between contact surfaces.

Molykote 41 will also serve to prevent normally closd switches from due to icing or corrosion.

You can write to me at satish@projectsalescorp.com or log onto www.projectsalescorp.com