Under certain conditions, the connections can constitute a source of heat such that after a long period the pieces of insulating material securing these connections can be negatively affected. A bad contact is a defect in a terminal, or in a connection that can lead to abnormal heat production. The bad contact test using heating wires is a test designed to simulate the overheating of a connection, taking into account the design of the connection and the current that passes through it under normal operating conditions, to simulate a the risk of fire. The test is intended to be applied only to screw terminal connections which the user or installer must make during the installation, maintenance or repair of the equipment and which are therefore beyond the control of the manufacturer. The test is applicable to screw terminals designed for a nominal current less than or equal to 63 A. NOTE — It is advisable to check other connection types by type testing and quality control methods. The glow wire test of standard UNE 20-672/2-1 or the needle burner test of standard UNE 20-672/2-2 can be applied to such insulated connections.