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complete solutions.
NCCER Electrical Test Preparation 99
complete solutions.
Article of the NEC covers grounding - ANSWER article 250
90 degree, explosion proof fitting - ANSWER GUAL
Dropout plate - ANSWER Metal plate with a curved surface for cable to follow as it passes from the tray
Common service voltages in the United States EXCEPT - ANSWER 372/575 3-PHASE, 4-WIRE
GFCI breaker - ANSWER Opens a circuit to prevent operation of an electrical device
What happens when one or more coils in a winding are grounded - ANSWER The motor will automatically blow fuses
Total connected load for eight incandescent lighting fixtures, each 120-volts, with a 200-watt lamp - ANSWER 13.3 amps
Must be grounded in a bussed gutter if used as the main service equipment - ANSWER Neutral busbar
When wall mounting cable tray, ensure that - ANSWER The building structure is strong enough to support the tray system
Purpose of sealing cable ends when reels of cable are in storage - ANSWER To keep moisture from creeping in
Outer covering on liquid-tight flexible metal conduit - ANSWER A moisture seal
complete solutions.
A good electrical connection should - ANSWER Be mechanically and electrically secure
Symbol normally used for duplex - ANSWER Circle with two parallel lines drawn through it
Disconnecting means are covered in - ANSWER NEC Section 110-
In relation to switches, the term throw refers to - ANSWER Number of internal operations that a switch can perform
A 3-phase, 4-wire, 480v service requires - ANSWER 3 current transformer(s)
Services conductors and equipment are covered in - ANSWER NEC Article 230
All receptacles installed on 25 amp and 20 amp branch circuits must be - ANSWER Grounding receptacles
The circular mil is based on - ANSWER Cross-sectional area of the wire
A transformer with the primary of 400 turns and a secondary of 300 turns has a - ANSWER Step-down turns ratio of 4:
Termination class that provides a seal against external elements - ANSWER Class 1
Calculations in AC circuits unless otherwise noted - ANSWER Rms values
When the coil turns are increased - ANSWER Induced voltage is increased
complete solutions.
Mineral insulated heating cable - ANSWER A type of heating cable that cannot be cut and terminated in the field.
CT under load - ANSWER The secondary should not be opened because of induced high voltage.
Transformer - ANSWER Electromagnetic Induction occurs.
Ground rod installation - ANSWER The top of the rod must be positioned flush with or below grade.
Offset bends - ANSWER The two kicks must be made perfectly parallel or the resulting offset will have a crooked bend.
Condulet as pulling point - ANSWER All types may be used for a 90 degree change in direction, except C.
Grounding system effectiveness - ANSWER Must limit the voltage on the electrical system and protect it from all undervoltage conditions.
Temporary power panel service - ANSWER The MOST common service used is 120/240 volt, 1-phase, 3- wire.
Overcurrent protective devices - ANSWER The 2 MOST common types are circuit breakers and fuses.
Insulation-resistance test instrument - ANSWER A megohmmeter is used to perform an insulation- resistance test on a 480-volt motor winding.
Seal in conduit - ANSWER Installed in a Class I location to prevent the passage of explosive gases in the conduit.
complete solutions.
OHM's law formula - ANSWER The correct formula is I=E/R.
Current transformer principle instrument - ANSWER A clamp-on ammeter operates on the current transformer principle.
Wiring diagram - ANSWER A drawing showing a point A to point B hookup of conductors.
HOA in motor control circuit - ANSWER Usually means Hands of Automatic.
Phase-to-phase voltage at load end - ANSWER For a 120/208 volt feeder with 5% voltage drop, it will be 197.60 volts.
Voltage - ANSWER Electromotive force.
Standard wire size system - ANSWER The standard wire size system used in the United States is AWG.
AL-CU switch - ANSWER Can be used with aluminum copper or copper clad aluminum wire.
Conduit fitting for access - ANSWER A fitting usually placed in the middle of a long run of rigid metal conduit.
Largest size of aluminum rigid conduit couplings - ANSWER 6 inches.
Thermocouple purpose - ANSWER To measure temperature.
Brass-colored terminal on receptacle - ANSWER Indicates it should be used to connect a hot wire.
Standard length of rigid conduit - ANSWER 10 feet.
complete solutions.
Symbol for primary side of a transformer - ANSWER H
Explosion-proof electrical fitting - ANSWER Using an amorphous sealed device
Use of a megger - ANSWER The electrician MUST be sure that the circuit is De-energized and locked, tagged out, and tested
Function of a ballast in a fluorescent fixture - ANSWER Steps up the voltage
Primary purpose of P&ID - ANSWER Provides scale drawings and piping and instrumentation control systems
Factor controlling speed of an induction motor - ANSWER Frequency
Distance between center-to-center bends for a 10-inch offset at 30 degrees - ANSWER 20 inches
Acceptable protection techniques for electrical equipment in hazardous locations - ANSWER Use duct- ignition proof equipment
Purpose of Lockout/Tagout - ANSWER Prevents operation
Equipment to locate a suspected short circuit in 1-phase of a 3-phase motor - ANSWER megger
1 line diagram with simplified symbols - ANSWER Indicates the interconnections and component parts of an electrical circuit
Effect of moisture inside a cadweld mold during welding - ANSWER The cadweld mold could explode
complete solutions.
Result of making 2 equal bends in opposite direction in a conduit run - ANSWER Offset
Unsupported means for cable trays - ANSWER #9 wire
Depths available for 4-inch square boxes - ANSWER 1 inch
Installed at an expansion joint for continuous ground between cable tray sections - ANSWER A bonding jumper
Color identifying insulated, grounded, number 4 conductors - ANSWER Green
Importance of torquing bolts when connecting busbars - ANSWER Decreases resistance on the connection
Protective devices for motors - ANSWER SOLENOID
Sizing of service conductors - ANSWER The total calculated load of the building
Number of complete AC cycles per second - ANSWER Frequency
Component of a dual element fuse - ANSWER Rejection clip
Holding contact in a motor starter - ANSWER Normally connected in parallel with the Start push button
Resistance of a circuit with 480 volts and 50amps - ANSWER 9.6 ohms
How a battery produces voltage - ANSWER Chemical reaction
