At my work place I have an electric door issue. it is activated when you swipe your ID badge through the card reader and the door unlatches. It was diagnosed as the olenoid that was faulty so a new solenoid was installed but is failing to operate correctly. The system is labelled as 24VDC. I tested the DC circuit and am reading -25.6 VDC. What does the minus sign mean? Does this explain why the door will not work.
Thank you all.
Thank you all.