R2 LT1 Flashcards
What switch design is largely preferred in bigger commercial and industrial installations where line voltage switches are used?
Toggle design
What does the term ‘grade’ refer to in switches?
Different levels of quality
What is the continuous current rating of most 20A switches?
16A
What does the R in R-2 refer to?
Receptacle
What are some variations of receptacles within the specification grade?
Commercial, construction, industrial, heavy-duty
How can you recognize isolated ground receptacles?
Green triangle on face
What is the key difference between a 15A and 20A receptacle?
Slot shape
What type of switch is most suitable for a 240V single-phase load where all live conductors are interrupted?
c. DPST
What are some variations within the specification grade of switches?
Commercial, construction, industrial, heavy-duty
How many terminals does a double-pole, double-throw (DPDT) switch have?
Six
What is the maximum voltage rating for L5-15R receptacles?
125V
What is the third grade of receptacles manufactured for?
To meet demanding requirements of hospital grade
What additional features may general-use switches include in their design?
Pilot lighting, dimmer function, motion-sensing capabilities
How many activation cycles are most certified electrical specification grade switches able to provide?
Thirty to fifty thousand
What does SPST stand for in switch terminology?
Single Pole Single Throw
What does a SPST switch’s actuator positions indicate?
ON or OFF
What is rotary activation?
Turning knob to activate mechanism
Which certification bodies are commonly found on switches sold in Canada?
CSA Group, UL, ULC
What does DPDT stand for?
Double Pole Double Throw
What ratings do general-use switches have?
Voltage, ampacity, horsepower
How are switches classified?
By their number of poles and throws
What is an SPST switch used for?
Simple on-off control of a single load
What are some example styles of general-use switches?
Doorjamb-mounted, pull-chain, key-locking, push-button
What is a DPDT switch equivalent to?
Two SPDT switches
How do general-use toggle switches activate?
Move handle up or down
What does the 15 in L5-15R refer to?
15A
What are the two styles in which fifteen- and twenty-amp non-locking receptacles are manufactured?
Standard style and decorator style
Why are specification grade devices more reliable?
Robust and longer service life
How can the hospital grade receptacles be identified?
By a green dot on the face
What is the purpose of isolated ground receptacles?
Supply sensitive electronic equipment
What is the shape of the slot for the identified conductor on a 15A receptacle?
Vertical
What is the shape of the slot for the identified conductor on a 20A receptacle?
T-slot
What is a key consideration with switches that have additional features like pilot lighting, dimmer function, and motion-sensing capabilities?
That the conductor is identified at the switch location
Where are residential grade switches generally used?
Residential installations
What CEC rule limits circuit loading to 80% of the rating of the overcurrent device?
CEC rule 8-104
Describe the activation method for Decora style switches.
Acts like a see-saw
Why do switch manufacturers limit the use of their devices to 80% of the marked ampacity?
Because the majority of circuit protection devices are not marked for continuous operation at their full ampacity.
What are some other activation methods for switches mentioned in the text?
Pull-chain, key, doorjamb
What must electrical equipment bear to show it has met safety standards in Canada?
Evidence of Approval
Why is it important to verify the electrical ratings of switches?
Ensure safe use within intended circuit
Why are switches intended to be installed within an enclosure?
Kept dry and free of dust
What does ‘throw’ mean in switch terminology?
The number of positions of the switch actuator
