Pump Station Control Diagram

The control circuit provides automatic and manual start-up of the pump station. Let's take a closer look at automatic startup. To do this, set switches S3, S4, S5 to "Automatic" position. Next, start the entire installation by pressing the S2 button. By supplying power to the electrical plant, voltage relays KV1, KV2, KV3 are powered and their contacts are closed in the circuits of contactors KM1, KM2, KM3. When the button S2 is pressed, it receives power from relay K1 - protection relay against automatic re-start of the pump in case of short-term system support and closes its contact K1.1 - button S2. In parallel, it receives power from the relay KM5, opening the gate valve of the first pump, and the relay of the magnetic starter KM1, closing its contacts and starting the engine of the first pump, and KM1 closes the contact KM1.3, after which the alarm of the first engine is turned on. At the same time, the time relay KT1 is powered with a time delay corresponding to the start of the engine. KT1 closes its contact KT1.2 in the control circuit of the second motor. It is powered by the relay KM6, opening the gate valve, and the relay of the magnetic starter KM2, starting the engine of the second pump, KM2 closes the contact KM2.3, the alarm of the second engine is turned on. At the same time, it receives power from the time relay KT2 and closes its contact KT2.2 in the motor control circuit of the third pump with time delay, then the third engine is switched on similarly. Manual start-up of the pump unit. To do this, set the set switches S3, S4, S5 to the position "Manual." The first engine is started by pressing S2 and SB1 button, the second and the third - by SB2 and SB3 buttons. Turning on the standby pump motor is an example of stopping the first pump. During the steady operation of the first pump, the normally closed contact of the relay of the magnetic starter KM 1.4 is in the open position. When the first engine is stopped (for example, the thermal relay has worked) in the control circuit of the first engine, the normally closed contact KK1 opens, the relay KM1 loses power and its normally closed contact KM1.1 returns to the initial position, that is, it opens. Thus, it receives power from voltage relay KV1 and closes its contact KV 1.1. At the same time, it receives power from the relay of the magnetic starter KM4, closes its contacts, and the backup engine starts. If all engines stop, the H5 "Alarm" signal goes off and the bell rings. By pressing S1 button the circuit is de-energized. Maximum protection of power circuits is provided by automatic switches SQ1, SQ2, SQ3, SQ4. Protection of ED against overload currents is provided by heat relays KK1... KK4. At currents exceeding the set points of the thermal relays, they open their contacts in the contactor circuits, as a result of which the engine is disconnected.