Lesson 404 - Timing Relays: On-Delay, Interval, and Recycle

c. off-delay

A device that starts its timing function after power is removed from its coil (mechanical-type) or if the external switch is opened (solid-state) is called a(n) ___ timer. Select one: a. recycle b. one-shot c. off-delay d. on-delay

d. interval

A mechanical-type ___ timer has contacts that change state at the same time control power is applied and revert to their original state after a predetermined period of time even though control power is still present. Select one: a. on-delay b. recycle c. off-delay d. interval

b. 11

A one-shot timing relay has an ___-pin base (socket). Select one: a. 8 b. 11

a. does

A retentive timer is a timer that ___ maintain its current accumulated time value when its control input signal is interrupted or power to the timer is removed. Select one: a. does b. does not

a. 8

An interval timing relay has an ___-pin base (socket). Select one: a. 8 b. 11

b. 11

An off-delay timing relay has an ___-pin base (socket). Select one: a. 8 b. 11

a. 8

An on-delay timing relay has an ___-pin base (socket). Select one: a. 8 b. 11

c. off-delay

At a predetermined period of time after the external switch has opened, the contacts of a solid-state ___ timer will change state. Select one: a. recycle b. one-shot c. off-delay d. on-delay

b. ON

Fifteen seconds after Sw 1 is closed, the red light will be ___. Select one: a. OFF b. ON

c. either a or b

For programmable logic relays (PLRs), the internal timers may be programmed with ___ format. Select one: a. function block diagram b. line (ladder) diagram c. either a or b d. neither a nor b

d. M2 is energized. When START is pushed and released, M2 de-energizes and M1 energizes. After 6 minutes, M1 de-energizes and M2 is energized again.

For the circuit shown below, which of the statements correctly describes the operation? TR is an ON-Delay Relay Select one: a. When START is pushed and released, M2 immediately energizes. After 6 minutes, M1 also energizes. b. M2 is energized. When START is pushed and released, M1 also energizes. After 6 minutes, M1 de-energizes while M2 remains energized. c. M2 is energized. When START is pushed and released, M2 de-energizes and the 6-minute time period begins. At the end of the timed period, M1 energizes. d. M2 is energized. When START is pushed and released, M2 de-energizes and M1 energizes. After 6 minutes, M1 de-energizes and M2 is energized again.

d. Neither M1 nor M2 is running. After START is pushed and released, M2 starts and runs for 2 minutes. M2 then stops and M1 starts. M1 continues to run until STOP is pushed.

For the diagram shown below, ___ is the correct sequence of operation. TR is an interval relay. Select one: a. Neither M1 nor M2 is running. After START is pushed and released, M1 starts and runs for 2 minutes. M1 then stops and M2 starts. M2 continues to run until STOP is pushed. b. Only M2 is running. After START is pushed and released, M2 stops immediately and M1 starts and runs for 2 minutes and stops. M2 then restarts and runs until STOP is pushed. c. M1 & M2 are both running. Immediately after START is pushed and released, M1 starts and runs for 2 minutes and then stops. When M1 stops, M2 starts and runs until STOP is pushed. d. Neither M1 nor M2 is running. After START is pushed and released, M2 starts and runs for 2 minutes. M2 then stops and M1 starts. M1 continues to run until STOP is pushed.

b. on-delay, off-delay, one-shot, and recycle

Four basic timing functions available on solid-state timers are ___. Select one: a. on-delay, off-delay, one-shot, and synchronous b. on-delay, off-delay, one-shot, and recycle c. on-delay, off-delay, one-shot, and dashpot d. on-delay, off-delay, synchronous, and dashpot

b. IV

In Figure 404-040, symbol ___ is used in a ladder diagram for an NC timed open set of contacts. Select one: a. II b. IV c. VI d. III e. I f. V

d. V

In Figure 404-040, symbol ___ is used in a ladder diagram for an NO timed closed set of contacts. Select one: a. I b. VI c. III d. V e. IV f. II

b. off-delay

Mechanical-type ___ timers are used in applications where the load is to remain energized for some preset period of time after control power has been removed. Select one: a. on-delay b. off-delay c. interval d. recycle

a. on-delay

NCTO contacts are associated with ___ timing relays. Select one: a. on-delay b. off-delay

a. on-delay

NOTC contacts are associated with ___ timing relays. Select one: a. on-delay b. off-delay

b. off-delay

NOTO contacts are associated with ___ timing relays. Select one: a. on-delay b. off-delay

b. True

ON-delay timer contacts do not change position until the set time period passes after the timer receives power. Select one: a. False b. True

a. programmed

Programmable logic relays (PLRs) have internal timers that are ___ into the control circuit. Select one: a. programmed b. hard-wired

a. 3

Refer to Figure 404-013. Point H on the ladder diagram should be connected at terminal ___ on the relay socket. Select one: a. 3 b. 1 c. 7 d. 4 e. 2

e. 1

Refer to Figure 404-013. Point J on the ladder diagram should be connected at terminal ___ on the relay socket. Select one: a. 2 b. 3 c. 7 d. 4 e. 1

d. 7

Refer to Figure 404-013. Point M on the ladder diagram should be connected at terminal ___ on the relay socket. Select one: a. 6 b. 8 c. 5 d. 7

a. OFF

Refer to Figure 404-042. Fifteen seconds after Sw 1 is closed, the red light will be ___. Select one: a. OFF b. ON

a. ON

Refer to Figure 404-042. Five seconds before Sw 1 is closed, the green light will be ___. Select one: a. ON b. OFF

a. OFF

Refer to Figure 404-042. One second after Sw 1 is closed, the red light will be ___. Select one: a. OFF b. ON

a. ON

Refer to Figure 404-042. Sw 1 has been closed for 40 seconds and is then opened. Five seconds after Sw 1 is opened, the green light will be ___. Select one: a. ON b. OFF

b. OFF

Refer to Figure 404-043. Fifteen seconds after Sw 1 is closed, the green light will be ___. Select one: a. ON b. OFF

b. OFF

Refer to Figure 404-043. Five seconds before Sw 1 is closed, the red light will be ___. Select one: a. ON b. OFF

b. OFF

Refer to Figure 404-043. One second after Sw 1 is closed, the red light will be ___. Select one: a. ON b. OFF

C

Select (as required) the NEMA or industry standard symbol for an NOTC set of timing relay contacts.

b. III

Select one: a. I b. III c. IV d. II

c. II

Select one: a. I b. IV c. II d. III

d. III

Select one: a. II b. I c. IV d. III

a. IV

Select one: a. IV b. II c. I d. III

d. 1323

Since a real-time clock for a PLC or PLR is based on 24 hr (military time), the required setting for operation at 1:23 pm is ___. Select one: a. 2323 b. 1123 c. 0123 d. 1323

a. ON

Sw 1 has been closed for 40 seconds and is then opened. Five seconds after Sw 1 is opened, the green light will be ___. Select one: a. ON b. OFF

c. both a and b

Synchronous clock timers are ___. Select one: a. AC operated b. accurate c. both a and b d. neither a nor b

b. ON

TR is a solid-state on-delay relay. Five seconds before Sw 1 is closed, the green light will be ___. Select one: a. OFF b. ON

b. OFF

TR is a solid-state on-delay relay. Five seconds before Sw 1 is closed, the red light will be ___. Select one: a. ON b. OFF

b. II & III only

The contacts of energized solid-state ___ relays change state immediately when the initiating contact (external switch) is closed. I. on-delay II. off-delay III. one-shot IV. interval V. recycle Select one: a. I only b. II & III only c. I & V only d. II & IV only e. I & IV only f. none of these

e. none of these

The contacts of energized solid-state ___ relays change state immediately when the initiating contact (external switch) is opened. I. on-delay II. off-delay III. one-shot IV. interval V. recycle Select one: a. I & V only b. I & IV only c. II & IV only d. II & III only e. none of these

b. IV only

The contacts of solid-state ___ relays change state immediately when coil power is applied. I. on-delay II. off-delay III. one-shot IV. interval V. recycle Select one: a. I & V only b. IV only c. II & IV only d. II & III only e. I only f. all of these

d. dashpot

The time delay period for a ___ timer is determined by how quickly air or liquid passes through an orifice. Select one: a. programmable b. synchronous clock c. solid-state d. dashpot

a. immediately

When coil voltage is applied, the contacts of a solid-state interval relay change state ___. Select one: a. immediately b. at the end of time period T

a. at the end of time period T

When coil voltage is applied, the contacts of a solid-state on-delay relay change state ___. Select one: a. at the end of time period T b. immediately

a. at the end of time period T

When coil voltage is applied, the contacts of a solid-state recycle relay change state ___. Select one: a. at the end of time period T b. immediately

a. II

Which of the diagrams shown in Figure 404-050 illustrates the operation of an interval relay? Select one: a. II b. I c. IV d. III

d. III

Which of the diagrams shown in Figure 404-050 illustrates the operation of an on-delay relay? Select one: a. I b. IV c. II d. III

d. Immediately, NO timed contacts open and NC timed contacts close.

Which of the following statements is true when the coil of an on-delay timing relay is de-energized? Select one: a. After a pre-programmed period of time, NO timed contacts close and NC timed contacts open. b. After a pre-programmed period of time, NO timed contacts open and NC timed contacts close. c. Immediately, NO timed contacts close and NC timed contacts open. d. Immediately, NO timed contacts open and NC timed contacts close.

a. On-delay

___ timers are the most commonly used timing relays. Select one: a. On-delay b. Off-delay c. One-shot d. Recycle

d. Recycle

___ timers are used when multiple fixed-timed outputs alternating from "ON" to "OFF" are required to control a load during the entire time control power is applied. Select one: a. ON-delay b. OFF-delay c. One-shot d. Recycle