Sliding Connections Between Chassis and Device (For Withdrawable Devices)
The sliding connections between the chassis and device are made up of two parts: clusters and disconnecting contacts. Grease between the clusters and the disconnecting contacts facilitates the connection and avoids damaging the silver-coated surface by reducing the racking-in friction.
The grease breaks down over time and it is therefore necessary to replace it regularly.
Preventive maintenance for the sliding connections consists in periodically removing grease and applying new grease in compliance with grease types recommended by Schneider Electric.
In sulphurous (corrosive) atmospheres (H2S/SO2), it is necessary to implement the cleaning procedure using Thiourea solution, with mandatory regreasing using the specified fluorinated grease. This type of grease protects the silver and copper-coated contacts against sulphuration, which can cause a build-up of silver or copper sulphide on the contacts. The insulating properties of silver or copper sulphide can increase the resistance of the contact and lead to greater temperature rise.