Electrically connected pressure gauge and time relay are connected in series to the control circuit

As shown in the figure, the circuit uses two time relays KT1 and KT2 connected in series with the contacts of the electrical contact pressure gauge SP to overcome the problem that during the critical time of the motor's automatic start or automatic stop, the liquid or gas pressure has not yet reached the point where the SP voltage is completely reduced. When the contacts are in contact or are not completely separated, the intermediate relay contacts will tremble or spark, which improves the reliability of the circuit.