Electrical contacts are often manufactured from relatively soft materials, which are subject to wear. Additionally the contact surface oxides, increasing resistance, there is a special product for lubricating electrical contacts.
Contact Grease ? CU contains copper particle which is used when you need particles (conductive) to assist in oxide breakup and you require good lubrication and abrasion. Example: disconnect switches or large connectors and relays.
- Has a good lubricating property, even with heavy wiping contacts
- Lowers resistance across contacts
- Prevents tracking and shorting out
- Eliminates arcing
- Loosens and softens oxide films
- Is not harmful to plastics and rubbers
- Protects metal parts against corrosion
While some of the above points may seem contradictory, in practice they are not. In a closed contact, the film of lubricant is thinly squeezed. Because it is so thin, the current passes freely through the Contact Grease – CU film across the contact.
In fact, because the Contact Grease CU takes up irregularities in the surface of the contact resistance is lowered and effective contact area is increased. When the contact begins to open, some of the grease strings across the gap, forming bridges. As this happens, the electrical resistance increases.
It is also this effect of reducing the flow of current, which eliminates arcing. Thus while Contact Grease ? CU does not normally allow current to flow through it, in the thin film squeezed between contacts it allows the current to flow freely.