How long must a dry motor be conducted before resting after the 1st attempt?

For the proper operation of the ERJ 170/175 aircraft, after conducting a dry motor attempt, it is essential to allow sufficient resting time before attempting another motor. This resting period is necessary to prevent overheating and to ensure that the electrical and mechanical systems have time to cool down. According to the procedures outlined for these aircraft, the duration for the rest period after the first dry motor attempt is mandated to be 5 minutes. This guideline helps maintain the integrity of the engines and systems during testing and prevents potential damage due to continuous operational stress. Understanding such limitations is vital for ensuring safety and reliability during ground operations.