Electrical Journeyman Test 2020 With Complete Questions And Answers Rated
A+
Clearance - (ANSWERS)A statement from a person of authority that a section of line has been
很高兴见到你
disconnected from all sources of energy.
Steps after taking a clearance - (ANSWERS)Test, Clean, Ground.
Ohm's Law - (ANSWERS)It takes one Volt to push one Amp through one Ohm of resistance.
Safe working position with conductors - (ANSWERS)Insulate and Isolate.
Full capacity of a transformer - (ANSWERS)Achieved by paralleling the coils.
Full potential of a transformer - (ANSWERS)Achieved by seriesing the coils.
Restoring service with a bad transformer in a Wye/Delta bank - (ANSWERS)Isolate bad
transformer, re-connect bank as open Wye/open Delta, tell customer to reduce load of 50%.
Visual Tie Between on a Wye/Wye bank - (ANSWERS)To stabilize secondary voltage.
Grounding the secondary side of a transformer - (ANSWERS)To protect lineman, customers,
and equipment.
Turns ratio determination - (ANSWERS)Divide highest secondary voltage into input voltage.
Requirements for transformers to be paralleled - (ANSWERS)Same voltage ratings, same
primary phase, same frequency, same tap, impedance within .2%.
Parallel single phase transformers - (ANSWERS)Verify same frequency, voltage ratings, taps,
polarity, and impedance is within .2%; connect to same primary phase; connect everything
except hot legs; energize transformer; use voltmeter to check voltage and phase out; make and
break on secondary side; mark with yellow is leaving paralleled.
Checking when connecting transformers in a bank - (ANSWERS)Voltage rating, Polarity,
Impedance, Frequency, Taps.
Overloaded transformer calculation - (ANSWERS)37,500 ÷ 7200 = 5.2Amps X 1.25 = 6.5Amps.
Transformer is overloaded but is pulling less than 125%, I would not change it.
Amps drawn by a 20HP motor at 240V - (ANSWERS)20HP X 746(watts per HP) = 14,920 W;
I=P÷E; 14,920 240V= 62.16Amps.
Most important aspect of any job - (ANSWERS)Safety.
A+
Clearance - (ANSWERS)A statement from a person of authority that a section of line has been
很高兴见到你
disconnected from all sources of energy.
Steps after taking a clearance - (ANSWERS)Test, Clean, Ground.
Ohm's Law - (ANSWERS)It takes one Volt to push one Amp through one Ohm of resistance.
Safe working position with conductors - (ANSWERS)Insulate and Isolate.
Full capacity of a transformer - (ANSWERS)Achieved by paralleling the coils.
Full potential of a transformer - (ANSWERS)Achieved by seriesing the coils.
Restoring service with a bad transformer in a Wye/Delta bank - (ANSWERS)Isolate bad
transformer, re-connect bank as open Wye/open Delta, tell customer to reduce load of 50%.
Visual Tie Between on a Wye/Wye bank - (ANSWERS)To stabilize secondary voltage.
Grounding the secondary side of a transformer - (ANSWERS)To protect lineman, customers,
and equipment.
Turns ratio determination - (ANSWERS)Divide highest secondary voltage into input voltage.
Requirements for transformers to be paralleled - (ANSWERS)Same voltage ratings, same
primary phase, same frequency, same tap, impedance within .2%.
Parallel single phase transformers - (ANSWERS)Verify same frequency, voltage ratings, taps,
polarity, and impedance is within .2%; connect to same primary phase; connect everything
except hot legs; energize transformer; use voltmeter to check voltage and phase out; make and
break on secondary side; mark with yellow is leaving paralleled.
Checking when connecting transformers in a bank - (ANSWERS)Voltage rating, Polarity,
Impedance, Frequency, Taps.
Overloaded transformer calculation - (ANSWERS)37,500 ÷ 7200 = 5.2Amps X 1.25 = 6.5Amps.
Transformer is overloaded but is pulling less than 125%, I would not change it.
Amps drawn by a 20HP motor at 240V - (ANSWERS)20HP X 746(watts per HP) = 14,920 W;
I=P÷E; 14,920 240V= 62.16Amps.
Most important aspect of any job - (ANSWERS)Safety.
