How a relay logic elevator works - YouTube Click to view on Bing1:14This dynamic circuit diagram (made for educational purpose) shows how a relay logic elevator works. Note that actually relays and contactors have a time response of a fraction of second.Author: electrovlogViews: 38K Dover Elevator - Hydraulic Pump Shuts Off - CR4 Discussion I have a Dover elevator single story 480 3 ph. On energizing, the hydraulic pump runs for about a minute and then shuts off. I have very limited schematics but I do see a pit safety switch in series with a power supply that could keep everything from working. Dover Elevator System, Inc. Dover Elevator Systems Inc., had been very flexible and forward looking to allow the highly sophisticated controller and traction machine of proprietary designs, to be manufactured in Malaysia, South Korea and China to make the products more cost effective in order to remain competitive in the market.