At present,the electric systems of underground electric- loader poweredLHDs,which were made in China and other countries,used the contact starters and break-ers,with the result that the power consumption was high atld the contacts were failed con-stantly.As viewed from these problems,the authors have developed a power-saving typecontactless starting control device.This paper describes in detail the basic principles andprotection functions of this new device,which can be used as a reference for the startingcontrol of underground elecfric-powered LHDs and other electromechanical equipment.