What can damage the insulation on supply connections at the motor starter?

The insulation on supply connections at the motor starter can be damaged by poor contacts or loose connections. When connections are not secure, it can lead to increased electrical resistance at the joint, generating heat due to the higher current flowing through the faulty contact. This heat can degrade the insulation over time, leading to eventual failure. Additionally, poor contacts can cause arcing and sparking, which can also contribute to insulation damage. In contrast, tight connections typically help prevent damage, while high voltage spikes could affect other components but are not a direct cause of insulation breakdown in the same way. Excessive heat can indeed damage insulation, but this is often a secondary effect resulting from other issues such as poor connectivity, making the understanding of contact integrity crucial in maintaining the health of motor starter connections.