motors
The part of a DC motor that makes electrical contact with the commutator to provide continuous voltage is the _____.
What is the brushes?
Operation of equipment or an electrical conductor beyond rated capacity, which will eventually cause damage or dangerous overheating.
What is a overload
One horsepower (hp) equals______of torque per second,
What is 550 foot-pounds of torque per second?
Which fixtures is designed for installation in the grid of a suspended ceiling?
What is a troffer fixture
In variable speed drives, what happens to horsepower in a constant torque load?
Horsepower increases and decreases in direct proportion to the speed.
Devices designed to open and close a circuit manually or automatically when a predetermined level of current exists, without damage to themselves when properly applied.
What is 430.109
Operation for alternate intervals of (1) load and no load, (2) load and rest, or (3) load, no load, and rest.
What is intermittent duty
A protective device that is an integral part of a motor or compressor that protects the motor against dangerous overheating due to overload or failure to start.
What is a thermal overload
A tungsten-halogen lamp is likely to contain _____ gas.
What is iodine
A motor controller must have a rating of no less than _____% of the motor full-load current.
What is 100%
According to the NEC Section 430.22when a single motor is supplied by a branch circuit, the ampacity must not be less than _____.
What is 125%
Devices designed to open and close a circuit manually or automatically when a predetermined level of current exists, without damage to themselves when properly applied.
What is a circuit breaker?
rpm
The number of shaft rotations made each minute, expected to be the approximate full-load speed of a motor at the rated power frequency.
Capacitance is measured in _____.
What is farads
What type of motor terminal arrangement has three coils connected and three coils isolated?
What is a wye connected motor
This is a type of single-phase induction motors has a start winding that is switched out of the circuit after the motor starts?
What is a capacitor start motor?
In a purely resistive circuit containing one 25-ohm resistor powered by 120VAC, the total current flow is _____ amps.
What is 4.8
Operation for alternate intervals of (1) load and no load, (2) load and rest, or (3) load, no load, and rest.
intermitant duty cycle
An electric current always produces _____.
what is a electric field
The NEMA design letter (A-F) refers to the motor's _____.
What is starting torque characteristics
A motor that has three sets of three leads with continuity between the wires in each set is a _____-connected motor.
What is a delta system
A component of electric motors or generators designed to reverse a unidirectional current.
What is a communtator
Operation at a substantially constant load for a period of three hours or more
What is continous duty
Capacitance is measured in _____.
What is 30mf
When is torque the highest
What is when force is applied