It has been brought to MCE’s attention that if the voltage level of 5 volt power supply feeding the controller computer (swing panel) falls below regulation, it can have adverse effect on the operation of the motor control. In certain situations, the elevator computer may become inoperable and motor field voltage can drop to zero. Having very low or no motor field control can result in the car drifting in the direction of the load due to lack of torque control. This scenario is only applicable to inspection operation. Automatic and passenger operation use additional software monitors and are not affected.
