MC II: Lesson 4 - Solid State Relays

Question 1

A ______ solid-state relay is an electronic device that performs the same function as an electromechanical relay.

a. non-programmable
b. programmable

Answer 1

a. non-programmable

Question 2

A ______ solid-state relay is an electronic device with control functions that include relays, timers, and counters.

a. non-programmable
b. programmable

Answer 2

b. programmable

Question 3

While a solid-state relay and an electromechanical relay perform the same function, the ______ relay has no moving parts as it switches electronically.

a. electromechanical
b. solid-state

Answer 3

b. solid-state

Question 4

The SSR operates as three independent circuits.

True or False

Answer 4

False

Question 5

The input circuit and the output circuit are electrically isolated from each other.

True or False

Answer 5

True

Question 6

SSRs are available with a variety of AC or DC input voltages, AC or DC output voltages, and output circuit ampacities from 3 amperes to 40 amperes.

True or False

Answer 6

True

Question 7

The input and output sections of an SSR are electrically isolated, by the use of a(n) ______.

a. control power transformer
b. optical coupling

Answer 7

b. optical coupling

Question 8

The input section of an SSR performs the same function as the ______ of an electromechanical relay.

a. coil
b. contact
c. overload

Answer 8

a. coil

Question 9

The output section of an SSR performs the same function as the ______ of an electromechanical relay.

a. coil
b. contact
c. overload

Answer 9

b. contact

Question 10

The type of load connection to the output circuit is the main consideration when selecting the switching method of a solid-state relay.

True or False

Answer 10

True

Question 11

______ switching is preferred for resistive loads because voltage and current are in phase in a purely resistive load; this allows the load to be switched on and off when voltage and current are at or near zero.

a. Instant-on
b. Peak
c. Zero

Answer 11

c. Zero

Question 12

______ switching is used with reactive loads or combinations of resistive and reactive loads, where the voltage and current are out of phase, and there is no advantage to switching at any particular point in the cycle. This switching method is identical to the operation of an electromechanical relay.

a. Instant-on
b. Peak
c. Zero

Answer 12

a. Instant-on

Question 13

______ switching is preferred for highly inductive or capacitive loads where voltage and current are nearly 90° out of phase, by switching when load voltage is at peak and load current is near zero.

a. Instant-on
b. Peak
c. Zero

Answer 13

b. Peak

Question 14

The electromechanical relay is more susceptible to temperature rise and voltage spikes than the solid state relay.

True or False

Answer 14

False

Question 15

A ______ can be used to protect SSRs from brief voltage spikes.

a. metal-oxide varistor
b. semiconductor fuse
c. zener diode

Answer 15

a. metal-oxide varistor

Question 16

Special ______ must be used to protect an SSR in a shorted condition.

a. metal-oxide varistors
b. semiconductor fuses
c. zener diodes

Answer 16

b. semiconductor fuse

Question 17

Intermittent problems or erratic operation with a programmable relay most likely indicates a ______ problem.

a. hardware
b. software

Answer 17

a. hardware

Question 18

Identify the NEMA ladder diagram symbols and letter code for a normally open and normally closed solid-state relay.

Answer 18

Question 19

______ the load is a condition that occurs when the load power is not present or too low, and the sensor input voltage never drops below SSR input drop value.

a. Erratic operation of
b. Failure to de-energize
c. Failure to energize

Answer 19

b. Failure to de-energize

Question 20

______ the load is a condition that occurs when the input control device is faulty.

a. Erratic operation of
b. Failure to de-energize
c. Failure to energize

Answer 20

c. Failure to energize

Question 21

______ occurs due to loose terminal connections, power source not operating within specifications, or ambient temperatures are out of range.

a. Erratic operation
b. Failure to de-energize
c. Failure to energize

Answer 21

a. Erratic operation

Question 22

Solid state relays cannot be used in 3-wire control schemes.

True or False

Answer 22

False