MC II: Lesson 4 - Solid State Relays Flashcards
A ______ solid-state relay is an electronic device that performs the same function as an electromechanical relay.
a. non-programmable
b. programmable
a. non-programmable
A ______ solid-state relay is an electronic device with control functions that include relays, timers, and counters.
a. non-programmable
b. programmable
b. programmable
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
b. solid-state
The SSR operates as three independent circuits.
True or False
False
The input circuit and the output circuit are electrically isolated from each other.
True or False
True
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
True
The input and output sections of an SSR are electrically isolated, by the use of a(n) ______.
a. control power transformer
b. optical coupling
b. optical coupling
The input section of an SSR performs the same function as the ______ of an electromechanical relay.
a. coil
b. contact
c. overload
a. coil
The output section of an SSR performs the same function as the ______ of an electromechanical relay.
a. coil
b. contact
c. overload
b. contact
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
True
______ 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
c. Zero
______ 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
a. Instant-on
______ 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
b. Peak
The electromechanical relay is more susceptible to temperature rise and voltage spikes than the solid state relay.
True or False
False
A ______ can be used to protect SSRs from brief voltage spikes.
a. metal-oxide varistor
b. semiconductor fuse
c. zener diode
a. metal-oxide varistor
Special ______ must be used to protect an SSR in a shorted condition.
a. metal-oxide varistors
b. semiconductor fuses
c. zener diodes
b. semiconductor fuse
Intermittent problems or erratic operation with a programmable relay most likely indicates a ______ problem.
a. hardware
b. software
a. hardware
Identify the NEMA ladder diagram symbols and letter code for a normally open and normally closed solid-state relay.
______ 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
b. Failure to de-energize
______ 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
c. Failure to energize
______ 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
a. Erratic operation
Solid state relays cannot be used in 3-wire control schemes.
True or False
False
