PLC Ch. 7 Review Practice Test.
PLC Ch. 7 Review Practice Test. Explain the difference between the timed and instantaneous contacts of a mechanical timing relay. - CORRECT ANSWER Instantaneous contacts change state as soon a the timer coil is powered while the delayed contacts change their state at the end of the time delay. Draw the symbol and explain the operation of each of the following timed contacts of a mechanical timing relay: a. On-delay timer - NOTC contact b. On-delay timer - NCTO contact c. Off-delay timer - NOTO contact d. Off-delay timer - NCTC contact - CORRECT ANSWER a. When de-energized TD1 contacts are open. When TD coil is energized the timing period starts. TD1 contacts are delayed from closing. After time delay period has elapsed, TD1 contacts close. When TD coil is de-energized TD1 contacts open instantly. b. When de-energized TD1 contacts are closed. When TD coil is energized the timing period starts. TD1 contacts are delayed from opening. After time delay period has elapsed, TD1 contacts open. When TD coil is de-energized TD1 contacts close instantly. c. When TD coil is de-energized TD1 contacts are open. When TD coil is energized the TD1 contacts close instantly. When the TD coil is de-energized the timing period starts. After time delay period has elapsed, TD1 contacts open. d. When TD coil is de-energized TD1 contacts are closed.
Información del documento
- Subido en
- 23 de julio de 2024
- Número de páginas
- 3
- Escrito en
- 2023/2024
- Tipo
- Examen
- Contiene
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