Electric valve motor control circuit

Photocoupler

The electric valve control circuit consists of the following three parts: the main line, the control line, and the energy brake line aa.

The main line includes the power switch landscape. QF, the main contacts of the three-phase AC contactors KM1, KM2, the components of the thermal relay FR and the three-phase AC motor. The control circuit includes control buttons SB1 - SB5 , line BH of AC contactors KM1 - KM3 and their auxiliary contacts, power transformers Tl, T2, signal indicators HL1 - HIA, flash switches S1, S2, state selection switches SA1, SA2 And position switches sQl, SQ2, etc. The energy consumption circuit includes a bridge rectifier uc, a current limiting potentiometer RP, a storage capacitor C, and a main contact of the AC contactor KM3. The electric valve motor control circuit is shown in Figure 4-35.

When the line is in the hot standby state, the main line can be controlled or uncontrolled by selecting the switch positions of SA1 and SA2. When SA1 (SA2) is on the left, the coil of KMl (KM2) exits. When t is running, when SAl (SAZ) is on the right, the coil of KMl (KM2) is put into operation. When SA1 (SA2) is on the left, the signal indicator points. Bright, the operator or maintenance personnel can use this file to check whether the control circuit is powered. When the SA1 (勖 address) is on the right, the signal indicator does not light. Only after the valve motor is started, the signal indicators HL1, H12 (HL3) :, .HIA) will flash. Close the power switch QF, set the selector switch SA1 to the right, press SB1 (or SB2), and the current passes through Vll-SB1 (or SB2)-KM2 contact (2-3)-KM1 coil--s02-- SAl--FR contact (7-9)--KM3 contact (9-10)-SB5-Wll.KM1 coil is energized and rotated from magnesium, valve motor, open the valve. After the contact (5-6) of the KM1 is turned on, the flash switch sl operates, and the red light HL1 and the green light HL2 serve as flash indications. When the valve is opened to the limit position, SQ2 is disconnected, the coil of KM1 is de-energized, its main contact is reset, the power supply of the valve electric 杌 is disconnected, and the valve motor stops working.

Set selector switch SA2 to the right, press SB3 (or SB4), the current depends on Vll-SB3 (~a"SB4) -*KMl contact (13-14)---KM2 coil-,-SQl- *SAZ-FR contact (7-9)-KM3 contact (9-10)-SB5-W11, KM2 coil is electrically attracted and rotated from the chain f door motor, closing the valve. The contact at KM2 ( 12-15) After turning on, the flash switch S2 works, the red light HL3 and the green light fflA are flashed. When the valve is closed to the limit position, the position switch sQl is disconnected. The KM2 coil is de-energized, its main contact is reset, the valve is closed. The power to the motor is turned off.

During the process of opening the valve, the stop button SB5 is pressed during the obstacle, and the breaking contact is disconnected, so that the KM1 or KM2 curve coil is de-energized and the motor is de-energized. At the same time, the SB5's moving contact (19-W11) is closed. The KM3 coil is electrically connected, its contact (9-10) is disconnected - preventing KM1 or KM2 from malfunctioning, and the main contact of KM3 is closed, making the bridge The output of the rectifier and the stored energy of the capacitor simultaneously act on the windings of the motor to generate a braking torque that causes the motor to stop instantaneously. In this way, the same door can be stopped to the specified position without any error. In Figure 4-35, the potentiometer RP acts as a current limiting device. The braking current can be obtained by adjusting the RP. Generally, the braking current is 4.5A. In Figure 4-35, the electrolytic capacitor can be selected according to the power of the valve. If the power of the valve motor is less than 2 kW, the capacitor of lOO-ZOOlJLF' can be used. If the power of the valve motor is between Z and 5. 5 kW, it can be used. 400t, F or so capacitor. The withstand voltage of the capacitor is above 600V.