POWDER METAL CONTACTS
|Contactors, circuit breakers, thermostats, intelligent switches, etc|
AgC contact materials show a very high resistance against contact welding and low contact resistance. Resistance against welding increases with increasing graphite content. AgC materials have self-lubricating behavior when used as sliding contacts.
Mainly used in protective switches such as MCBs, MCCBs, residual current protective switches, or motor protective switches. Application is normally in asymmetric match with AgNi,AgW, AgWC or Cu.
Contacts made of AgW show a high anti-welding resistance and a high resistance to arc erosion due to high melting point and high hardness of W, they also have a good electrical and thermal conductivity.
AgW materials are mainly used in low voltage MCCB and ACB and protective switches.
The AgWC contact materials containing the refractory component WC have high hardness and resistance to mechanical wear, a low tendency towards contact welding, and a relatively stable contact resistance in service. AgWC contacts are produced by powder metallurgy infiltration.
Mainly used in heavy-duty switching devices, such as circuit breakers. residual current circuit breakers. In many cases they are used in asymmetric match with AgC
Due to high Ag content , AgWCC contacts have low contact resistance. They have very high anti-welding properties due to containing tungsten carbide and graphite with high melting point. AgWCC contacts are manufactured by sintering.
Mainly used in heavy-duty switching devices, such as circuit breakers. residual current circuit breakers. In many cases they are used in asymmetric match with AgNi, AgW or AgWC.
AgNiC contacts combine the advantages ofAgNi and AgC contacts. They have good resistance to electrical erosion and anti-welding properties.
AgNiC contacts are mainly used in MCCB, ACB.
CuW contact materials have excellent resistsnce against arc erosion and anti-welding properties up to very high curret. CuW contacts are produced in a great variety of shapes by means of powder metallurgy (pressing / sintering or infiltration). The tungsten content is 50%-80%.
CuW contacts are mainly used in medium and high voltage switchgears. Typical applications are in high voltage circuit breakers, load switches, transformer switches tap changers and low voltage arcing contacts.
In addition, CuW materials are widely used as electrodes, primarily for welding.
|Cu Content (wt.%)||50±2||40±2||30±2|
|EIec.Resistivity (p0 cm)||≤3.20||≤3.70||≤4.10|