ETCP Electrical Exam

RMS voltage =

.707 of peak

What must be on Lock-out Devices

1 - Identity of employee applying device 2 - the Date the device was applied 3 - a legend that says:"Do Not Energize"

Live work is only permitted under NFPA 70E (Standard for Electrical Safety in the Workplace) if...

1- locking out all sources of Energy is Not possible 2- de-energizing a circuit will introduce a greater hazard (e.g., life support system)

Dip Switch Settings 1 thru 9

1-2-4-8-16-32-64-128-256

Power =

1. [VxI] 2. [RxIsquared] 3. [V2/R]

Power Factor formulas

1. cosine[phase angle] 2. Power[watts]/[VxI] 3. Real Power[watts]/Apparent Power[VA]

Maximum length of ethernet cable is

100 meters/328 ft.

What is considered to be the maximum allowable cable length for a DMX Cable?

1000 meters (3281')

Minimum Voltage allowable on a 120v branch circuit?

116.4 (3%)

Most Chain motors designed for use in North America operate correctly on___________ voltages

120/208v

Most Common service found at a Company switch in North America is?

120/208v 3-phase

maximum % of phase current found thru neutral

173%

A follow spot puts out 100fc @200 ft with a 40ft beam size. What is the beam size and foot candles at 100'

20 ft and 400fc (1/2 the size, 4x times the intensity)

An Arc Flash Can reach as much as _____________degrees F.

20,000º

NEC. Rule allowing an over-current device to be located 25 feet after a change in cable size.

25 foot Tap Rule (sec.520-69)

Maximum Allowable Voltage Drop on Feeders or Branch Circuits

3%

The rule for Lightning is called the

30/30 rule (if you hear thunder within 30 seconds of lightning, shut down outdoor generator and wait 30 minutes after last lightning strike to re-start)

Maximum units on multi-point bus (daisy chain)

32 Units

Maximum Total Allowable Voltage Drop non Both Feeder and Branch Circuits

5%

DMX can control _______ dimmers per universe in ________ steps per device

512 - 256

The average value of a fully rectified sinewave is __________ of peak

62%

Copper expands at what rate when vaporized in an Arc Flash?

67,000X

DMX-512 is an ___ bit Protocol

8-bit

Active Load

A load in which the power consumed doesn't change if the applied voltage changes.

Passive Load

A load in which the resistance doesn't change if the applied voltage changes.

Soft Patch

Assignment of Dimmers to virtual control channel

On single purchase counter-weight battens, what is the First action an Electrician should take?

Attach all fixtures before loading counter-weights

LED's are inherently___________ loads

Capacitive

When metering the load side of a transformer supplying 120/208v 3-phase, what is the minimum category meter to be used?

Category III

Servicing Chain Motor

Check Voltage to Coil

The best method for definitively determining the ampacity of a power panel is...

Check ampacity indicated on Breaker feeding the Company Switch

DMX- 512 Operates at __________ Kbytes per sec

DMX@ 250Kbytes Per sec

Meg-ohm meter (commonly called a megger)

Device for testing the effectiveness of insulation

A Bull/Company Switch allows an Electrician to

Disconnect Power from a System

Half the Voltage at the same Resistance

Draws 1/2 the Current

For low hanging Fog effect a technician would use________

Dry Ice

Personal Equipment required when working on 240v equipment where available fault current is unknown

Flame Resistant long Sleeve Shirt, Flame Resistant Pants, and Safety Glasses

DMX to Ethernet/Ethernet to DMX connectors

Gateway or Protocol converter

On a twist lock connector the __________ connects first when mating

Ground

A Rig of 208V HMI fixtures are on branch circuit breakers from distribution panel. The breakers are within rated use for the current load but are extremely hot, most likely from?

Harmonics

HRC

High Rupture Capacity Fuses

In the case of Resistive Loads current is_______with the Voltage

In phase

What does an Extension Cord extend?

It extends the electrical outlet to the power supply cord

In an Inductive Load the current ________ the Voltage

Lags

In the case of Capacitive Loads current_______ the Voltage

Leads

Cable Pick

Length = A + B - C

Chain Motor is a _________ load

Linear

An incoming road board requires 300A of 3-phase , how best to assure for a successful load-in?

Locate a company switch fed by a transformer capable of delivering the required 300a

When installation of tails are required at Company panel, the safest way to proceed is...

Lock-out/Tag-out the breaker feeding the panel serving as the Company switch

At one venue the Chain Motors worked properly with 100' of cable run. At next venue a cable run was 300' and the motors became intermittent. Why?

Longer cable run caused a Voltage drop

Cold Filament

Low Resistance\Large In-Rush Current

MBJ\SBJ

Main Bonding Jumper\ Secondary Bonding Jumper

Connection that returns fault current to the source

Make First\Break Last

A isolated ground 120v outlet, used in conjunction with an isolation transformer has an

Orange triangle on its face

An Opto-Splitter can protect a lighting system from_____on the DMX Cable

Over Voltage

Single Phase AC power formula

P(watts) = V x I x PF

Phase angle of 90 degrees =

PF of 0

Phase angle of 0 degrees =

PF of 1

An Inductor is to current what a___________ is to water.

Paddle wheel

Regarding OSHA/OHSA compliance for the entertainment electrician______is a concern

Personel Protection Equipment

P.O.E.

Power over Ethernet allows 48vdc over 2 unused wires

To assemble a Cat 5 data cable, use a _________ tool

RJ-45 crimp tool, jacket stripper, cable shears

K - Factor

Rating of how well transformers can handle loads current in the neutral conductor

RMD

Remote device management

Lost power is proportional to the _________ in the circuit

Resistance

Power Factor of 1 is a______load

Resistive

Lost power is proportional to the________ of the_________ flowing thru the circuit

Square of the Current

When a 3phase motor runs incorrectly in reverse rotation you should...

Swap two of the phase connections

If two control devices are connected on an Ethernet switch but can't communicate

The IP address settings are incorrect (should have the same network portion)

Neutrals can be referred to as

The grounded conductor; a normally current-carrying conductor

The best reason to power up a large Rig in sections is?

The initial power surge can overload power sources

Power is

The rate of doing work

The best way to deal with a non-sinusoidal load is to use a _________

Transformer with a High K-rating or an HMT

Best diagnostic tool for working with SCR dimmer system is a ______

True RMS Digital Meter

DMX cable must be

Twisted pair, low capacitance, and 120-ohm characteristic impedance

Use a _______ type fire extinguisher on electrical fires.

Type C extinguisher

Hots can be referred to as

Ungrounded conductors, phase conductors, live conductors

Vpeak =

V

Power (Watts) =

V x I

10.0.0.1 is a ______

Valid IP address

8 LED fixtures are separately controlled by a lighting console but currently units #2 & #7 are operating in unison. What's most practical troubleshooting step?

Verify that the DMX address of each unit is unique.

Apprent Power =

Voltage x Current

Peak Voltage formula

Vpeak = Vrms/1.414

VRMS =

Vpeak x 0.707

RMS Voltage formula

Vrms = Vpeak x 0.7071

If a lighting designer asks you to "Flag" a light what do you do?

Wave a hand in front of Luminaire

Loss of power due to resistance is known as

[I squared]R (copper loss/winding loss)

3-phase AC power per leg formula

[KVA / V x 1.732]/3

Electricity takes________________to return to source

as many paths available to it

Best location to ground a portable power generator providing supplementary power to a building for a show?

at house service entry (where power enters building) or service panel

Power Factor =

cos (phase angle between voltage and current)

Inductive loads have___________ fields

electromagnetic

Capacitive loads have_____________ fields

electrostatic

Three Phase kVA (formula)

kVA = (ILine x VLine x 1.732)/1000

Single Phase kVA (formula)

kVA = [Iphase x Vphase]/1000

AED UNIT will....

not shock if heartbeat is detected

Best Material for temporarily hanging 15 Luminares on ___?

schedule 40 iron pipe

NEC Code for: - Stage - Carnivals - Motion Picture

stage 520, carnivals 525, motion Picture 530

If fall protection has been used it must be

taken out of service

DMX "Slot to channel" best describes _______

the function of a Soft patch on a console