Where a 150 kva Study guides, Class notes & Summaries

A 150 kVA service transformer has a 480Y/277 volt 3-phase primary and a 208Y/120 volt, 3-phase secondary. What is the approximate full-load ampere rating of the primary of the transformer? correct answer: 180 amperes Where a conductor is marked RHW-2 on the insulation what does the "-2" represent? correct answer: The conductor has a maximum operating temperate of 90 degrees C. For a grounded electrical system supplied by a feeder or branch circuit, the equipment grounding conductor sha...

Conductors with _____ marked on the insulation are NOT approved for use in a wet location. - correct answer THHN conductors with THHN insulation are approved for use in dry and damp locations only and conductors with THWN, THHW, and THW insulation are recognized for use in dry and wet locations. Given: A one-family dwelling unit with a demand load of 200 amperes is supplied with a 120/240 volt, single-phase, electrical system from the local utility company. What is the MINIMUM size aluminu...

The National Electrical Code® (NEC) requirements found in Section 450.3 are for the protection of ? . - Answer-The windings of the transformer only Where primary-only protection for transformers is provided with rated currents of nine amperes or more, the basic rule requires that each transformer rated 1,000 volts, nominal, or less be protected by an individual overcurrent protective device on the primary side, rated or set at not more than ? of the rated transformer primary current. - Answe...

Conductors with _____ marked on the insulation are NOT approved for use in a wet location. - Answer THHN conductors with THHN insulation are approved for use in dry and damp locations only and conductors with THWN, THHW, and THW insulation are recognized for use in dry and wet locations. Given: A one-family dwelling unit with a demand load of 200 amperes is supplied with a 120/240 volt, single-phase, electrical system from the local utility company. What is the MINIMUM size aluminum THW ...

1. Disregarding exceptions, dry-type transformers located indoors having a rating of greater than _____ shall be installed in a transformer room of fire-resistant construction. A. 75 KVA B. 87 1/2 KVA C. 112 1/2 KVA D. 50 KVA - ANSWER-C- 112 1/2 KVA 450.21(B) pg 335 2. What is the MINIMUM height allowed for a fence enclosing an outdoor installation of 2,400 volt electrical equipment? A. 6 feet B. 7 feet C. 8 feet D. 9 feet - ANSWER-B - 60 7 feet 110.31 pg 49 3. Where powe...

1. Disregarding exceptions, dry-type transformers located indoors having a rating of greater than _____ shall be installed in a transformer room of fire-resistant construction. A. 75 KVA B. 87 1/2 KVA C. 112 1/2 KVA D. 50 KVA - ANSWER-C- 112 1/2 KVA 450.21(B) pg 335 2. What is the MINIMUM height allowed for a fence enclosing an outdoor installation of 2,400 volt electrical equipment? A. 6 feet B. 7 feet C. 8 feet D. 9 feet - ANSWER-B - 60 7 feet 110.31 pg 49 3. Where powe...

Journeyman Practice Test Questions and Answers Conductors with _____ marked on the insulation are NOT approved for use in a wet location. -Answer-THHN conductors with THHN insulation are approved for use in dry and damp locations only and conductors with THWN, THHW, and THW insulation are recognized for use in dry and wet locations. Given: A one-family dwelling unit with a demand load of 200 amperes is supplied with a 120/240 volt, single-phase, electrical system from the local utility co...

Conductors with _____ marked on the insulation are NOT approved for use in a wet location. - THHN conductors with THHN insulation are approved for use in dry and damp locations only and conductors with THWN, THHW, and THW insulation are recognized for use in dry and wet locations. Given: A one-family dwelling unit with a demand load of 200 amperes is supplied with a 120/240 volt, single-phase, electrical system from the local utility company. What is the MINIMUM size aluminum THW conductor...

Standard Ratings for Transformers (written on back page of NEC) correct answers15, 30, 45 ,75, 122.5, 150, 225, 300, 500, 750, 1000 ALL IN KVA (apparent power) What are the 2 types of transformers? correct answersDry type and liquid filled type Dry type transformer correct answersCommonly indoors and outdoors For 480 - 208/120V transformers Cooling medium is air Liquid type tranformer correct answersUsed for higher voltages Cooling medium is typically oil Must have containment if ...

Journeyman Electrician Practice Test Questions And Answers Conductors with _____ marked on the insulation are NOT approved for use in a wet location. - ANS THHN conductors with THHN insulation are approved for use in dry and damp locations only and conductors with THWN, THHW, and THW insulation are recognized for use in dry and wet locations. Given: A one-family dwelling unit with a demand load of 200 amperes is supplied with a 120/240 volt, single-phase, electrical system from the ...