Mixed Deck — All CME Topics Flashcards

What is the purpose of a contactor's auxiliary contact in a motor control circuit?

Answer: Provide a holding circuit to maintain the contactor energized after the start button is released

The normally-open auxiliary (sealing) contact creates a parallel path around the momentary start pushbutton, latching the coil circuit closed after the button is released.

Per NEC 680.22, what type of receptacles are required within 6 to 10 feet of the inside walls of a permanently installed swimming pool?

Answer: GFCI-protected receptacles

NEC 680.22(A)(1) requires all receptacles located between 6 and 10 feet of a permanently installed pool to be GFCI protected.

When a master electrician's employee makes a serious code violation due to a misunderstanding of instructions, professional responsibility dictates that the master electrician should:

Answer: Accept accountability, correct the violation, and provide additional training to prevent recurrence

The master electrician is responsible for the actions of those working under their supervision and must correct errors and improve processes.

What is the consequence of non-compliance in CME professional practice?

Answer: Potential fines, license revocation, legal liability, and reputational damage

Non-compliance can result in significant consequences including monetary fines, suspension or revocation of professional licenses, civil or criminal liability, lawsuits, and lasting damage to professional reputation.

In designing a motor control center (MCC) for an industrial plant, what is the minimum short-circuit current rating (SCCR) that must be marked on the MCC assembly per NEC 409.110?

Answer: 5,000A minimum unless labeled for specific ampere rating

NEC 409.110(4) requires industrial control panels to be marked with their SCCR, with a minimum of 5,000A unless the panel is marked for a specific higher rating.

A Master Electrician employs unlicensed workers to perform work that requires a licensed electrician. This is primarily a violation of:

Answer: State electrical licensing law

Allowing unlicensed individuals to perform work requiring a license violates state electrical licensing statutes, which the state licensing board enforces.

When grounding an indoor separately derived AC system, such as a dry-type transformer, which of the following must be used as the grounding electrode?

Answer: The building or structure grounding electrode system.

NEC 250.30(A)(4) mandates that for an indoor separately derived system, the building or structure's existing grounding electrode system must be used as the grounding electrode for the new system. This ensures all grounded systems within the building are bonded together, minimizing potential differences.

What is the primary purpose of a 'punch list' at the end of a construction project?

Answer: To document incomplete or deficient items that must be corrected before final payment

A punch list is a final inspection document identifying remaining deficiencies or incomplete work items the contractor must address before receiving final payment.

Under the Fair Labor Standards Act (FLSA), non-exempt employees must receive overtime pay at what rate for hours worked beyond 40 per week?

Answer: 1.5 times the regular rate of pay

The FLSA mandates that covered, non-exempt employees receive at least one and one-half times their regular hourly rate for all hours worked beyond 40 in a workweek.

An electrical installation in a commercial building is modified by the utility, resulting in a higher available fault current (AFC) at the service equipment. Per NEC 110.24(B), what is the primary action required by the master electrician?

Answer: Recalculate the AFC and adjust the field-installed label on the service equipment.

NEC 110.24(B) requires that when modifications to the electrical installation affect the maximum available fault current at the service, the AFC must be verified or recalculated. The required field marking must then be adjusted to reflect the new AFC level to ensure the service equipment ratings are still sufficient.

What is the consequence of failing to adhere to electrical codes and standards?

Answer: Failure can lead to accidents, fines, injuries, and damage.

Failing to adhere to electrical codes and standards carries severe consequences, as these regulations are designed to prevent hazards. Non-compliant installations significantly increase the risk of electrical fires, shocks, and equipment damage, potentially leading to serious injuries or even fatalities. Additionally, such failures can result in costly fines, legal liabilities, and invalidated insurance claims.

When sizing the supply conductors for an industrial machine per NEC 670.4(A), what is the minimum ampacity required relative to the machine's full-load current rating?

Answer: 125% of the machine's full-load current rating

NEC 670.4(A) requires supply conductors for industrial machinery to be sized at not less than 125% of the machine's nameplate full-load current.

In a switchboard installation, what is the minimum headroom required in front of the equipment per NEC 110.26(A)(3)?

Answer: 6.5 feet

NEC 110.26(A)(3) requires a minimum headroom of 6.5 feet (2.0 m) in front of electrical equipment 600V or less.

Under NEC Article 547, receptacles in agricultural buildings that are subject to moisture must have:

Answer: GFCI protection

NEC 547.5(G) requires GFCI protection for receptacles in areas of agricultural buildings exposed to moisture to protect against electric shock.

When a service disconnect is located remotely from the meter, what is required at the meter location per NEC 230.82?

Answer: A means to disconnect all conductors from the service entrance conductors

NEC 230.82 lists equipment permitted on the supply side of the service disconnect, and the primary requirement for remote disconnects is that a means to disconnect all conductors must be accessible.

When two qualified electricians perform group lockout/tagout, what must each individual do?

Answer: Apply their own personal lock to a hasp on each energy isolation point

Group LOTO requires each individual to apply their own personal lock to the hasp so no single person can inadvertently restore energy.

A master electrician is bidding on a project where the scope is not fully defined and significant changes are anticipated. Which type of contract would best protect the electrician from financial loss due to unforeseen work and scope modifications?

Answer: Cost-Plus Contract

A Cost-Plus contract is most appropriate when the scope of work is not clearly defined. Under this model, the contractor is reimbursed for the actual costs incurred (labor, materials, etc.) plus an agreed-upon fee or percentage for overhead and profit. This structure minimizes the contractor's risk from unknown conditions, unlike a Lump Sum contract which would be very risky.

Why is energy efficiency important in electrical systems design?

Answer: To reduce operational costs and minimize environmental impact.

Energy efficiency in electrical systems design focuses on minimizing wasted energy, which directly translates to lower electricity bills and reduced operational costs over the system's lifespan. Furthermore, by consuming less energy, the system contributes to a smaller carbon footprint and reduced demand on power generation, thereby minimizing environmental impact. It's a key aspect of sustainable and cost-effective design.

According to NFPA 70E, what is the minimum approach boundary within which all exposed energized conductors operating at 601–2,500V must be treated as energized?

Answer: Limited approach boundary

The limited approach boundary is the closest distance at which unqualified persons are permitted and within which all conductors must be treated as energized.

A 120/240V, 1-phase service supplies a dwelling with 24,000 VA total demand load. What is the calculated service entrance conductor ampacity?

Answer: 100 A

I = VA / V = 24,000 / 240 = 100 A; service entrance conductors must be rated for the full calculated load.