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? - ANSWER180 amperes
A 50 kVA transformer with a 480-volt, 3-phase, primary and a 208Y/120 volt, 3-phase sec...
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? -
ANSWER180 amperes
A 50 kVA transformer with a 480-volt, 3-phase, primary and a 208Y/120 volt, 3-phase secondary is to
be installed. Overcurrent protection is required on both primary and secondary sides of the
transformer. Determine the MAXIMUM standard size overcurrent protection device permitted on the
primary side. - ANSWER150 amperes
A commercial building is to be supplied with a transformer having a 480Y/277 volt, 3-phase primary
and a 208Y/120 volt, 3-phase secondary. The secondary will have a balanced computed demand load
of 416 amperes per phase. The transformer is required to have a MINIMUM kVA rating of _____ . -
ANSWER150 kVA
A fifteen (15) ft. horizontal run of rigid metal conduit (RMC) is to be installed between two enclosures
located in a Class II, Division 1 hazardous location. One enclosure is dust ignition-proof; the other is
not. The NEC® requires a MINIMUM of _____ sealing fittings. - ANSWERNone required
A motel to be constructed will have two (2), 20-ampere, 120-volt branch circuits provided for the
exterior electric signs. Determine the demand load, in VA, for the electric signs, on the feeder and
service-entrance conductors. - ANSWER3,000 VA
A panelboard is limited to 42 overcurrent protective devices where _____. - ANSWERthe panelboard
is a "split-bus" type panelboard
A recreational vehicle campground has one hundred-fifty (150) campsites provided with electrical
power. Twenty-five (25) of the campsites are reserved as tent sites. How many of the sites are
required to have a 20-ampere, 125-volt receptacles provided? - ANSWER150
A thermal barrier shall be required if the space between the resistors and reactors, of 600 volts or
less, and combustible material is LESS than _____. - ANSWER12 inches
, A twenty-five (25) ft. long tap conductor tapped from a 100 ampere rated feeder conductor, shall
have an ampacity of NOT less than _____. - ANSWER33.3 amperes
AFCI protection is required for all 15- and 20-ampere, 120-volt branch-circuits supplying outlets
located in _____. - ANSWERguest rooms and guest suites of hotels and motels that are provided with
permanent provisions for cooking
After all demand factors have been taken into consideration for an office building, the demand load
is determined to be 90,000 VA. Where the building has a 120/240 volt, single-phase electrical
system, what MINIMUM size copper conductors with THHW insulation are required for the
underground installed ungrounded (phase) service-lateral conductors? - ANSWER500 kcmil
After applying all demand factors, the ampacity of the service-entrance conductors are required to
be NOT less than _____ where both the overcurrent device and its assembly are not listed for
operation at 100 percent of their rating. - ANSWERthe sum of the noncontinuous loads plus 125
percent of the continuous loads
All 15- and 20-ampere, 125- and 250-volt, nonlocking receptacles installed in a wet location shall be
listed _____ type. - ANSWERweather-resistant
All 240-volt, twist-lock, 30-ampere receptacles on a construction site where supplied from a
temporary service, are required to be provided with _____when not covered by an assured
grounding program. - ANSWERGFCI protection
All metallic switchgear rated for over 600 volts shall be provided with a grounding busbar for the
purpose of connecting the _____. - ANSWERmetallic shield of cables
An aluminum grounding electrode shall be _____. - ANSWERprohibited
An emergency system is required to have NO more than _____ to have power available in the event
of failure of the normal electrical supply system. - ANSWER10 seconds
An inverse time circuit breaker used as the disconnecting means for a 50 hp, 480-volt, three-phase
continuous-duty, induction-type ac motor shall have an ampere rating of at LEAST _____. -
ANSWER75 amperes
An outdoor motor fuel gasoline dispensing pump is considered to be a Class I, Division 2
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller ClassRep2. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $13.49. You're not tied to anything after your purchase.
