Описание работы типовых релейно-контакторных электрических схем управления электроприводами, страница 4

                                                                                                                                                       
   А    В    С            N                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         QF                       SB2                                                                                                 SB1                                                                   KT1                                                                                           KM1.2                                                                                                                                                                                                          KT1.1                                                                               KM1                                                                                                                                                          KT1.2                                            KM1                                                                                                                                                                                                                                                                                                                                                                                                                                         KM1.1                          TV                                             M1                                                                                                                                                                                                               HL                                                                                                                                                                                                                                                                                                                                                                               

Рисунок 7.6 – Схема управления электроприводом с подачей перед  
                            включением рабочего механизма предупредительного
                            светового сигнала

          Схема управления (рисунок 7.7) позволяет осуществить управление двигателем по циклу: ход «вперёд», на время Δt₁, реверс, ход «назад» на время Δt₂, реверс и повторение цикла. Причём повторение циклов будет прекращено только после нажатия кнопки стоп SB1.

          Включение двигателя осуществляется кнопкой SB2. Подаётся напряжение на электромагниты управления контактора КМ1 и реле времени КТ1. Контактор КМ1 подключает двигатель на ход «вперёд» на период времени, зависящий от величины уставки времени, на которую настроены контакты КТ1.3 и КТ1.2. После истечения времени уставки контакт КТ1.3 отключает электромагнит управления контактора КМ1.

А     В      С      N                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    QF1                               SB2                                                                                                  SB1                                          KM1   KT1.3                                                                                  KM2.1                                                                                                                                                                                                                            КТ1.1                                                                                                                                                                                           KM1                    KM2                                                KT1                                                                          KT2.2                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     KT1.2           KM2                                                                                                                            KT2.3                                                                                   KM1.1                                                                                                                                                                  М1     М1                                    KT2.1                                                                                                                                                                                                                                                                        KT2                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              TV                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         KM1.2             HL1                                                                                                                                                                                                           KM2.2                       HL2