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What size wire for a 20 amp breaker

#12

Biggest hand bender

1 1/4"

Ground fault protected system must operate to cause the service disconnect to open all ungrounded conductors to fault to circuit, maximum setting of the ground fault protection is _________ amperes and the maximum time delay is _________ seconds or ground fault occurs equal to or greater than 3000 amperes

1,200 amps / one second

What is the power factor for a purely resistive circuit

100%

Percentage for continuous duty

125%

Small remote ungrounded sewage pump room includes an indoor pinpoint 150 watt work light type lumineer on a 1/2 Hp, 120 volt single phase continuous duty pump motor. What is the minimum ampacity for this line single branch circuit where the indoor work light is to be used as a non continuous load

13.5 amps

Alternator turning at 3600 RPM is produced in 60 cycle voltage. How many stator poles are used in the alternator?

2 poles

Using the law of proportion you find the total current for the circuit

2.3 amps

Industrial plant with a total load 1,513kva, power factor of 87% which results in 908kvar of reactive power. How many 45kvar units will be required to correct out of phase condition without causing a leading power factor?

20 units

Counter top spaces _________ or more must have a recep

24" Article 210.52 (C)(1)

Largest solid size bare copper

4 AWG

Max amps for Control Transformers

5 Amps

Primary voltage of 480v created at 45 KVA 3 phase. Determine the maximum size circuit breaker protected transformer providing the primary only protection

70 amps table 240.6 (A) table 450.3 (B) (125% 9 amps or more)

One horsepower equals

746 watts

What is the power factor for a 3 phase load in the situation below?

76.79%

What is the max load for an overcurrent protection device

80%

Define Silicon Controlled Rectifier and its use in a variable frequency drive

A solid state device that varies current to change motor speed

Define Ground Fault Protection

A system intended to provide protection of equipment from damaging line-to-ground fault currents by operating to cause a disconnecting means to open all ungrounded conductors of the faulted circuit

6" offset is to be formed on a 3/4" emt conduit which one of the combinations is an acceptable offset?

A. 22.5 degree with 12" center to center (2.5 multiplier) B. 30 degree with 12 1/2" center to center (2 multiplier) C. 45degree with 8 1/2" center to center (1.41 multiplier) Answer is C

Define UFER

An electrical earth grounding method. It uses a concrete encased electrode to improve grounding in dry areas

Determine the maximum rating of the motor branch short circuit and ground fault protected device, 125hp, 480v, 3 phase induction motor where the starting current has an issue with tripping. Table 430.52 value using an inverse time fix trip circuit breaker.

Answer on test 450

Their are two critically important issues involved in securing job safety

Awareness and Common sense

What following functions do arc chutes perform in relationship to the arc

Contain, divide, extinguish

Define Buck-Boost transformers

Designed to reduce (buck) or raise (boost) line voltage from 5-20%. Small single phase transformers

When correcting power factor for motors, capacitors should be installed no further than the LOAD side of the

Disconnect

How often do you need a recept in a hallway

Every 10'

Material cost for a large conduit bending job can be reduced by using what?

Field made bends

Manual motor starters are used for

Fractional-horsepower motors

When resistance is added to a circuit current _____________

Goes down

EGC (Equipment Grounding Conductor)

Has to be put in everything whenever you are running wire

Define Inrush Current

Highest current that's available when applying power

Define Overtravel

How much further the armature switch travels once it makes contact

NODODE

Normally Open Delay On De-Energize

NODOE

Normally Open Delay On Energize

A standard limit switch is made up of what

Operator head, Actuator, Body

All ungrounded service conductors must have _________ but not necessarily short circuit protection

Overload protection

Which one of the following fuses would be the best selection for a DC photovoltaic source and output circuits?

Photovoltaic solar UL2579

Apprenticeship program exist with the primary purpose of__________

Producing future craftsman

The voltage of a dual voltage motor is doubled 115v to 230v the current is ___________

Reduced by half

How do Auto Transformers work

Reduced voltage starting. Reduces the load on the motor then you can ramp it up without having a large current in rush. Start it slowly then bring it up to speed.

Auto transformer used for reduced voltage motor starting is a method of reducing current through the motor windings and _____________ during the motor starting?

Reducing load on the power distribution circuit

In Paralleling GenSets, the _________ fields are connected in _________

Series / Parallel

DODE timers are _________ if they require an external switch

Solid state

Where can't you utilize standard lock nuts and bushings

Supply side service disconnect lock nuts can't be used

If the grounded metal outlet box is _____________ and there is direct metal to metal contact between the mounting strap of the device and the grounding metal box, the equipment bonding jumper is not required

Surface mounted

If you double the voltage what happens to the current

The current gets cut in half


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