Thought you might enjoy this circuit as it is quite an interesting one. We have a star delta starter which needs to change an electric valve position before it starts. When it stops, the valve needs to open again and wait for the next start.
What makes this even more interesting is the fact that we have two different control voltages, 230V on the pump circuit and 24V on the valve circuit. With the pump in the off position, the control valve needs to be open. This valve interacts with yet another circuit that will maintain the “priming” of the pump. Once we initiate the start cycle, auto or manual, we need to ensure that the valve is shut before the pump is allowed to start
When wiring and testing the circuit, we found that the electronics of the valve control created a feedback voltage which prevented the valve from shutting when the pump was stopped. This was an easy fix by breaking the one signal wire via the relay. We also opted to have a timer that will determine the runtime of the pump. Once started, we will allow the pump a pre-set time to run and then shut down. The float switch in the circuit is a high level only and there is no low level float in place, hence the timer
Have a look at the circuit below and see if it makes sense. It is a rather unusual circuit and possibly not something you would come across too often but I thought it would be worth having a look at.
Hope you enjoy the post and remember, Work Safe! No Risk is EVER Worth it in our trade.