1. Pre-opening Control Board Product Characteristic ® Specially designed circuit, Enables the safety , operation of the elevator during advanced door opening or re-leveling with door opening. ® Safety relays which use different metal materials in one set contactor to assure that the contactor will not stick. ®@ Modularized design, suitable for standard manufacturing , reduces errors in wire connection. ® Standard guide-rall card slot bottom shell, convenient for control cabinet installation. ® Complies with EN81,GB7588, passes