Solenoids and Control Relays Flashcards
A relay is an electromagnetically controlled ___.
A) amplifier
B) breaker
C) sensor
D) switch
D) switch
Machine tool relays typically have ___ contacts, but may have as many as ___ contacts.
A) 1 to 4 / 10
B) 2 to 4 / 8
C) 2 to 8 / 12
D) 2 to 10 / 16
C) 2 to 8 / 12
Match the control relay type to the correct current rating.
I. Most 10 A, some up to 15 A
II. Most 10 A, some up to 20 A
III. Most 10 A, some up to 60 A
IV. 10 to 30 A load dependent
A) General Purpose
B) IEC - Machine Control
C) NEMA - Machine Control
D) General Purpose - Plug-in
I. - B
II. - C
III. - A
IV. - D
AC solenoids or relays tend to chatter unless a(n) ___ coil is added.
A) eddy
B) laminate
C) shading
C) shading
When the latch coil of a(n) ___ latching relay is energized, the contacts change to their activated state. At the same time, a mechanical mechanism engages and holds the contacts in this state even after the latch coil is de-energized. When the unlatch coil is energized, it trips the mechanical mechanism, allowing the contacts to return to their normal state.
A) impulse
B) magnetic
C) mechanical
C) mechanical
The ___ rule is an explanation of the direction of a magnetic field around a coil relative to the direction of the current in the coil, where a left hand is used to illustrate the relationship.
A) left-hand coil
B) left-hand conductor
C) right-hand coil
D) right-hand conductor
A) left-hand coil
The type of load connection to the output circuit is the main consideration when selecting the switching method of a solid-state relay.
A) True
B) False
A) True
___ latching relays use residual magnetic force to hold the contacts in position after the coil is de-energized.
A) Impulse
B) Magnetic
C) Mechanical
B) Magnetic
___ type latching relays have a single coil that operates a cam mechanism to change the state of the contacts each time the coil is energized (pulsed) for a minimum of 50 milliseconds.
A) Impulse
B) Magnetic
C) Mechanical
A) Impulse
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
Solid-state relays cannot be used in 3-wire control schemes.
A) True
B) False
B) False
Contacts on relays that can be configured as either NO contacts or NC contacts are called ___ contacts.
A) auxiliary
B) convertible or reversible
C) interposing
D) inverter
B) convertible or reversible
___ latching relays have either single or dual coils.
A) Impulse
B) Magnetic
C) Mechanical
B) Magnetic
The SSR operates as three independent circuits.
A) True
B) False
B) False
Loss of a phase, overvoltage, undervoltage, and out of sequence (phase rotation) are conditions that can be detected by ___ sequence relays.
A) frequency
B) phase
C) voltage sensing
B) phase
