Card Set Information
what is the phase to phase voltage of a delta system?
what is the phase to phase voltage of a wye system?
it is 2 times the neutral voltage
how are switches defined and categorized?
by the number of poles and throws
ladder diagrams are known as elementary diagrams
how are contacts of a drum switch manipulated?
rotation of the switch
drum switches are capable of handling currents larger than normal pilot devices
what are limit switches composed of?
actuator and contacts
what are the 2 most common types of proximity switches?
inductive and capacitive
what are 2 types of starter motors?
manual and magnetic
the first thing to do when troubleshooting relays is_____
check for voltage
why are overload relays used?
to protect the motor
how are seal in contacts placed relative to start button contacts?
what configuration do push buttons usually come in?
normally open and normally closed
which starter is operated by a coil inside the contactor?
what are AC motors primarily composed of?
stator, rotor, and end plates
what are the 3 basic parts of a DC motor?
frame, end plates and armature
what determines the speed of an AC induction motor?
the # of poles... more poles make less speed and more power. less poles make more speed and less power.
what are the 2 windings of a single phase motor?
run and start
if poles are removed from an AC motor, speed and horsepower will NOT increase
how do you change rotation on a 3 phase motor?
swapping 2 leads or using a drum switch
what would happen to a single phase AC motor if run winding and start winding were left energized?
they would burn up
what is the opposition of electron flow in a DC circuit?
what is an AC wave form called?